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Image: Udo Jandrey
22.03.2024

New model for sustainable structures of textile-reinforced concrete

By reinforcing concrete with textiles instead of steel, it is possible to use less material and create slender, lightweight structures with a significantly lower environmental impact. The technology to utilise carbon fibre textiles already exists, but it has been challenging, among other things, to produce a basis for reliable calculations for complex and vaulted structures. Researchers from Chalmers University of Technology, in Sweden, are now presenting a method that makes it easier to scale up analyses and thus facilitate the construction of more environmentally friendly bridges, tunnels and buildings.

By reinforcing concrete with textiles instead of steel, it is possible to use less material and create slender, lightweight structures with a significantly lower environmental impact. The technology to utilise carbon fibre textiles already exists, but it has been challenging, among other things, to produce a basis for reliable calculations for complex and vaulted structures. Researchers from Chalmers University of Technology, in Sweden, are now presenting a method that makes it easier to scale up analyses and thus facilitate the construction of more environmentally friendly bridges, tunnels and buildings.

"A great deal of the concrete we use today has the function to act as a protective layer to prevent the steel reinforcement from corroding. If we can use textile reinforcement instead, we can reduce cement consumption and also use less concrete − and thus reduce the climate impact," says Karin Lundgren, who is Professor in Concrete Structures at the Department of Architecture and Civil Engineering at Chalmers.

Cement is a binder in concrete and its production from limestone has a large impact on the climate. One of the problems is that large amounts of carbon dioxide that have been sequestered in the limestone are released during production. Every year, about 4.5 billion tonnes of cement are produced in the world and the cement industry accounts for about 8 percent of global carbon dioxide emissions. Intensive work is therefore underway to find alternative methods and materials for concrete structures.

Reduced carbon footprint with thinner constructions and alternative binders
By using alternative binders instead of cement, such as clay or volcanic ash, it is possible to further reduce carbon dioxide emissions. But so far, it is unclear how well such new binders can protect steel reinforcement in the long term.

"You could get away from the issue of corrosion protection, by using carbon-fibres as reinforcement material instead of steel, because it doesn't need to be protected in the same way. You can also gain even more by optimising thin shell structures with a lower climate impact," says Karin Lundgren.

In a recently published study in the journal Construction and Building Materials, Karin Lundgren and her colleagues describe a new modelling technique that was proved to be reliable in analyses describing how textile reinforcement interacts with concrete.

"What we have done is to develop a method that facilitates the calculation work of complex structures and reduces the need for testing of the load-bearing capacity," says Karin Lundgren.

One area where textile reinforcement technology could significantly reduce the environmental impact is in the construction of arched floors. Since the majority of a building’s climate impact during production comes from the floor structures, it is an effective way to build more sustainably. A previous research study from the University of Cambridge shows that textile reinforcement can reduce carbon dioxide emissions by up to 65 percent compared to traditional solid floors.

Method that facilitates calculations
A textile reinforcement mesh consists of yarns, where each yarn consists of thousands of thin filaments (long continuous fibres). The reinforcement mesh is cast into concrete, and when the textile-reinforced concrete is loaded, the filaments slip both against the concrete and against each other inside the yarn. A textile yarn in concrete does not behave as a unit, which is important when you want to understand the composite material's ability to carry loads. The modelling technique developed by the Chalmers researchers describes these effects.

"You could describe it as the yarn consisting of an inner and an outer core, which is affected to varying degrees when the concrete is loaded. We developed a test and calculation method that describes this interaction. In experiments, we were able to show that our way of calculating is reliable enough even for complex structures," says Karin Lundgren.

The work together with colleagues is now continuing to develop optimisation methods for larger structures.

"Given that the United Nations Environment Programme (UNEP) expects the total floor area in the world to double over the next 40 years due to increased prosperity and population growth, we must do everything we can to build as resource-efficiently as possible to meet the climate challenge," says Karin Lundgren.

Source:

Chalmers | Mia Halleröd Palmgren

Smart glove teaches new physical skills Image: Alex Shipps/MIT CSAIL
18.03.2024

Smart glove teaches new physical skills

Adaptive smart glove from MIT CSAIL researchers can send tactile feedback to teach users new skills, guide robots with more precise manipulation, and help train surgeons and pilots.

You’ve likely met someone who identifies as a visual or auditory learner, but others absorb knowledge through a different modality: touch. Being able to understand tactile interactions is especially important for tasks such as learning delicate surgeries and playing musical instruments, but unlike video and audio, touch is difficult to record and transfer.

Adaptive smart glove from MIT CSAIL researchers can send tactile feedback to teach users new skills, guide robots with more precise manipulation, and help train surgeons and pilots.

You’ve likely met someone who identifies as a visual or auditory learner, but others absorb knowledge through a different modality: touch. Being able to understand tactile interactions is especially important for tasks such as learning delicate surgeries and playing musical instruments, but unlike video and audio, touch is difficult to record and transfer.

To tap into this challenge, researchers from MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) and elsewhere developed an embroidered smart glove that can capture, reproduce, and relay touch-based instructions. To complement the wearable device, the team also developed a simple machine-learning agent that adapts to how different users react to tactile feedback, optimizing their experience. The new system could potentially help teach people physical skills, improve responsive robot teleoperation, and assist with training in virtual reality.

Will I be able to play the piano?
To create their smart glove, the researchers used a digital embroidery machine to seamlessly embed tactile sensors and haptic actuators (a device that provides touch-based feedback) into textiles. This technology is present in smartphones, where haptic responses are triggered by tapping on the touch screen. For example, if you press down on an iPhone app, you’ll feel a slight vibration coming from that specific part of your screen. In the same way, the new adaptive wearable sends feedback to different parts of your hand to indicate optimal motions to execute different skills.

The smart glove could teach users how to play the piano, for instance. In a demonstration, an expert was tasked with recording a simple tune over a section of keys, using the smart glove to capture the sequence by which they pressed their fingers to the keyboard. Then, a machine-learning agent converted that sequence into haptic feedback, which was then fed into the students’ gloves to follow as instructions. With their hands hovering over that same section, actuators vibrated on the fingers corresponding to the keys below. The pipeline optimizes these directions for each user, accounting for the subjective nature of touch interactions.

“Humans engage in a wide variety of tasks by constantly interacting with the world around them,” says Yiyue Luo MS ’20, lead author of the paper, PhD student in MIT’s Department of Electrical Engineering and Computer Science (EECS), and CSAIL affiliate. “We don’t usually share these physical interactions with others. Instead, we often learn by observing their movements, like with piano-playing and dance routines.

“The main challenge in relaying tactile interactions is that everyone perceives haptic feedback differently,” adds Luo. “This roadblock inspired us to develop a machine-learning agent that learns to generate adaptive haptics for individuals’ gloves, introducing them to a more hands-on approach to learning optimal motion.”

The wearable system is customized to fit the specifications of a user’s hand via a digital fabrication method. A computer produces a cutout based on individuals’ hand measurements, then an embroidery machine stitches the sensors and haptics in. Within 10 minutes, the soft, fabric-based wearable is ready to wear. Initially trained on 12 users’ haptic responses, its adaptive machine-learning model only needs 15 seconds of new user data to personalize feedback.

In two other experiments, tactile directions with time-sensitive feedback were transferred to users sporting the gloves while playing laptop games. In a rhythm game, the players learned to follow a narrow, winding path to bump into a goal area, and in a racing game, drivers collected coins and maintained the balance of their vehicle on their way to the finish line. Luo’s team found that participants earned the highest game scores through optimized haptics, as opposed to without haptics and with unoptimized haptics.

“This work is the first step to building personalized AI agents that continuously capture data about the user and the environment,” says senior author Wojciech Matusik, MIT professor of electrical engineering and computer science and head of the Computational Design and Fabrication Group within CSAIL. “These agents then assist them in performing complex tasks, learning new skills, and promoting better behaviors.”

Bringing a lifelike experience to electronic settings
In robotic teleoperation, the researchers found that their gloves could transfer force sensations to robotic arms, helping them complete more delicate grasping tasks. “It’s kind of like trying to teach a robot to behave like a human,” says Luo. In one instance, the MIT team used human teleoperators to teach a robot how to secure different types of bread without deforming them. By teaching optimal grasping, humans could precisely control the robotic systems in environments like manufacturing, where these machines could collaborate more safely and effectively with their operators.

“The technology powering the embroidered smart glove is an important innovation for robots,” says Daniela Rus, the Andrew (1956) and Erna Viterbi Professor of Electrical Engineering and Computer Science at MIT, CSAIL director, and author on the paper. “With its ability to capture tactile interactions at high resolution, akin to human skin, this sensor enables robots to perceive the world through touch. The seamless integration of tactile sensors into textiles bridges the divide between physical actions and digital feedback, offering vast potential in responsive robot teleoperation and immersive virtual reality training.”

Likewise, the interface could create more immersive experiences in virtual reality. Wearing smart gloves would add tactile sensations to digital environments in video games, where gamers could feel around their surroundings to avoid obstacles. Additionally, the interface would provide a more personalized and touch-based experience in virtual training courses used by surgeons, firefighters, and pilots, where precision is paramount.

While these wearables could provide a more hands-on experience for users, Luo and her group believe they could extend their wearable technology beyond fingers. With stronger haptic feedback, the interfaces could guide feet, hips, and other body parts less sensitive than hands.

Luo also noted that with a more complex artificial intelligence agent, her team's technology could assist with more involved tasks, like manipulating clay or driving an airplane. Currently, the interface can only assist with simple motions like pressing a key or gripping an object. In the future, the MIT system could incorporate more user data and fabricate more conformal and tight wearables to better account for how hand movements impact haptic perceptions.

Luo, Matusik, and Rus authored the paper with EECS Microsystems Technology Laboratories Director and Professor Tomás Palacios; CSAIL members Chao Liu, Young Joong Lee, Joseph DelPreto, Michael Foshey, and professor and principal investigator Antonio Torralba; Kiu Wu of LightSpeed Studios; and Yunzhu Li of the University of Illinois at Urbana-Champaign.

The work was supported, in part, by an MIT Schwarzman College of Computing Fellowship via Google and a GIST-MIT Research Collaboration grant, with additional help from Wistron, Toyota Research Institute, and Ericsson.

Source:

Alex Shipps, MIT CSAIL

Empa researcher Simon Annaheim is working to develop a mattress for newborn babies. Image: Empa
11.03.2024

Medical textiles and sensors: Smart protection for delicate skin

Skin injuries caused by prolonged pressure often occur in people who are unable to change their position independently – such as sick newborns in hospitals or elderly people. Thanks to successful partnerships with industry and research, Empa scientists are now launching two smart solutions for pressure sores.

If too much pressure is applied to our skin over a long period of time, it becomes damaged. Populations at high risk of such pressure injuries include people in wheelchairs, newborns in intensive care units and the elderly. The consequences are wounds, infections and pain.

Skin injuries caused by prolonged pressure often occur in people who are unable to change their position independently – such as sick newborns in hospitals or elderly people. Thanks to successful partnerships with industry and research, Empa scientists are now launching two smart solutions for pressure sores.

If too much pressure is applied to our skin over a long period of time, it becomes damaged. Populations at high risk of such pressure injuries include people in wheelchairs, newborns in intensive care units and the elderly. The consequences are wounds, infections and pain.

Treatment is complex and expensive: Healthcare costs of around 300 million Swiss francs are incurred every year. "In addition, existing illnesses can be exacerbated by such pressure injuries," says Empa researcher Simon Annaheim from the Biomimetic Membranes and Textiles laboratory in St. Gallen. According to Annaheim, it would be more sustainable to prevent tissue damage from occurring in the first place. Two current research projects involving Empa researchers are now advancing solutions: A pressure-equalizing mattress for newborns in intensive care units and a textile sensor system for paraplegics and bedridden people are being developed.

Optimally nestled at the start of life
The demands of our skin are completely different depending on age: In adults, the friction of the skin on the lying surface, physical shear forces in the tissue and the lack of breathability of textiles are the main risk factors. In contrast, the skin of newborns receiving intensive care is extremely sensitive per se, and any loss of fluid and heat through the skin can become a problem. "While these particularly vulnerable babies are being nursed back to health, the lying situation should not cause any additional complications," says Annaheim. He thinks conventional mattresses are not appropriate for newborns with very different weights and various illnesses. Annaheim's team is therefore working with researchers from ETH Zurich, the Zurich University of Applied Sciences (ZHAW) and the University Children's Hospital Zurich to find an optimal lying surface for babies' delicate skin. This mattress should be able to adapt individually to the body in order to help children with a difficult start in life.

In order to do this, the researchers first determined the pressure conditions in the various regions of the newborn's body. "Our pressure sensors showed that the head, shoulders and lower spine are the areas with the greatest risk of pressure sores," says Annaheim. These findings were incorporated into the development of a special kind of air-filled mattress: With the help of pressure sensors and a microprocessor, its three chambers can be filled precisely via an electronic pump so that the pressure in the respective areas is minimized. An infrared laser process developed at Empa made it possible to produce the mattress from a flexible, multi-layered polymer membrane that is gentle on the skin and has no irritating seams.

After a multi-stage development process in the laboratory, the first small patients were allowed to lie on the prototype mattress. The effect was immediately noticeable when the researchers filled the mattress with air to varying degrees depending on the individual needs of the babies: Compared to a conventional foam mattress, the prototype reduced the pressure on the vulnerable parts of the body by up to 40 percent.

Following this successful pilot study, the prototype is now being optimized in the Empa labs. Simon Annaheim and doctoral student Tino Jucker will soon be starting a larger-scale study with the new mattress with the Department of Intensive Care Medicine & Neonatology at University Children's Hospital Zurich.

Intelligent sensors prevent injuries
In another project, Empa researchers are working on preventing so-called pressure ulcer tissue damage in adults. This involves converting the risk factors of pressure and circulatory disorders into helpful warning signals.

If you lie in the same position for a long time, pressure and circulatory problems lead to an undersupply of oxygen to the tissue. While the lack of oxygen triggers a reflex to move in healthy people, this neurological feedback loop can be disrupted in people with paraplegia or coma patients, for example. Here, smart sensors can help to provide early warning of the risk of tissue damage.

In the ProTex project, a team of researchers from Empa, the University of Bern, the OST University of Applied Sciences and Bischoff Textil AG in St. Gallen has developed a sensor system made of smart textiles with associated data analysis in real time. "The skin-compatible textile sensors contain two different functional polymer fibers," says Luciano Boesel from Empa's Biomimetic Membranes and Textiles laboratory in St. Gallen. In addition to pressure-sensitive fibers, the researchers integrated light-conducting polymer fibers (POFs), which are used to measure oxygen. "As soon as the oxygen content in the skin drops, the highly sensitive sensor system signals an increasing risk of tissue damage," explains Boesel. The data is then transmitted directly to the patient or to the nursing staff. This means, for instance, that a lying person can be repositioned in good time before the tissue is damaged.

Patented technology
The technology behind this also includes a novel microfluidic wet spinning process developed at Empa for the production of POFs. It allows precise control of the polymer components in the micrometer range and smoother, more environmentally friendly processing of the fibers. The microfluidic process is one of three patents that have emerged from the ProTex project to date.

Another product is a breathable textile sensor that is worn directly on the skin. The spin-off Sensawear in Bern, which emerged from the project in 2023, is currently pushing ahead with the market launch. Empa researcher Boesel is also convinced: "The findings and technologies from ProTex will enable further applications in the field of wearable sensor technology and smart clothing in the future."

Source:

Dr. Andrea Six, Empa

Feathers from waterfowl (c) Daunen- und Federnverbände Mainz
05.03.2024

Adhesives: Feathers replace petroleum

Adhesives are almost always based on fossil raw materials such as petroleum. Researchers at Fraunhofer have recently developed a process that allows to utilize keratin for this purpose. This highly versatile protein compound can be found, for instance, in chicken feathers. Not only can it be used to manufacture a host of different adhesives for a variety of applications, but the processes and end products are also sustainable and follow the basic principles underlying a bioinspired circular economy. The project, developed together with Henkel AG & Co. KGaA, addresses a billion-dollar market.

Adhesives are almost always based on fossil raw materials such as petroleum. Researchers at Fraunhofer have recently developed a process that allows to utilize keratin for this purpose. This highly versatile protein compound can be found, for instance, in chicken feathers. Not only can it be used to manufacture a host of different adhesives for a variety of applications, but the processes and end products are also sustainable and follow the basic principles underlying a bioinspired circular economy. The project, developed together with Henkel AG & Co. KGaA, addresses a billion-dollar market.

Adhesives are found nearly everywhere: in sports shoes, smartphones, floor coverings, furniture, textiles or packaging. Even auto windshields are glued into place using adhesives. Experts recognize more than 1,000 different types of adhesives. These can bond almost every imaginable material to another. Adhesives weigh very little and so lend themselves to lightweight design. Surfaces bonded with adhesive do not warp because, unlike with screw fastenings, the load is distributed evenly. Adhesives do not rust, and seal out moisture. Surfaces bonded with adhesive are also less susceptible to vibration. Added to which, adhesives are inexpensive and relatively easy to work with.

Feathers from poultry meat production
Traditionally, adhesives have almost always been made from fossil raw materials such as petroleum. The Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB has recently adopted a different approach. Researchers there have been using feathers as a base material instead of petroleum. Feathers are a by-product of poultry meat production. They are destroyed or mixed into animal feed. But feathers are far too valuable to go to waste because they contain the structural protein keratin. This biopolymer is found in animals and makes up talons, claws, hooves or feathers. Its fibrous structure is extremely strong.

Why keratin is perfect for manufacturing adhesives
Keratin is a biodegradable and thus eco-friendly material whose structure has specific properties that make it particularly suitable for the manufacture of adhesives. Keratin's polymer structure, i.e., its very long-chain molecules, as well as its ability to undergo cross-linking reactions predestine it for the manufacture of various adhesives. “The properties required for adhesives are to some extent already inherent in the base material and only need to be unlocked, modified and activated,” explains project manager Dr. Michael Richter.

Platform chemical and specialty adhesives
Over the past three years, Fraunhofer IGB has been working with Henkel AG & Co. KGaA on the KERAbond project: “Specialty chemicals from customized functional keratin proteins” — Kera being short for keratin, combined with the English word bond. Henkel is a global market leader in the adhesives sector.

The partners in the project have recently developed and refined a new process. In the first stage, feathers received from the slaughterhouse are sterilized, washed and mechanically shredded. Next, an enzyme process splits the long-chain biopolymers or protein chains into short-chain polymers by means of hydrolysis.

The output product is a platform chemical that can serve as a base material for further development of specially formulated adhesives. “We use the process      and the platform chemical as a “toolbox” to integrate bio-enhanced properties into the end product,” says Richter. This means parameters can be specified for the target special adhesive such as curing time, elasticity, thermal properties or strength. Also, it’s not just adhesives that are easy to manufacture but also related substances such as hardeners, coatings or primers.

In the next stage, the Fraunhofer team set about converting the feathers on a large scale. Ramping up the process fell to the Fraunhofer Center for Chemical-Biotechnological Processes CBP in Leuna. The aim was to prove that the keratin-based platform chemicals can also be manufactured cost-efficiently on an industrial scale. This involved processing several kilograms of chicken feathers, with the material produced being used for promising initial material trials at Fraunhofer IGB and Henkel.

Foundations of a bioinspired economy
This bioinspired process is of particular significance for the Fraunhofer-Gesellschaft. Biotechnology is in fact one of the main fields of research for the Fraunhofer-Gesellschaft: “We draw our inspiration from functionality or properties that already exist in nature or in natural raw materials. And we attempt to translate these properties into products through innovative manufacturing methods. This generates a bioinspired cycle for valuable raw materials, Richter explains.

The project carries some economic weight. According to Statista, around one million tons of adhesives were manufactured in Germany alone in 2019. Total value is around 1.87 billion euros.

A patent application has been filed for the new process and an article published in a scientific journal. Two PhD students who have conducted extensive research on the project at Henkel and Fraunhofer are expected to complete their theses in the first quarter of 2024. This new keratin-based technology will allow a host of platform chemicals to be produced in a sustainable, bioinspired way.

The KERAbond project has been funded and supported over the past three years by Fachagentur Nachwachsende Rohstoffe (FNR) in Gülzow on behalf of the Federal Ministry of Food and Agriculture (BMEL) under the Renewable Resources Funding funding program (grant number 22014218).

Source:

Fraunhofer IBG

Photo: guentherlig, Pixabay
01.03.2024

The most tasteful kind of coating

Tiny external structures in the wax coating of blueberries give them their blue colour, researchers at the University of Bristol can reveal. This applies to lots of fruits that are the same colour including damsons, sloes and juniper berries.

In the study, published in Science Advances, researchers show why blueberries are blue despite the dark red colour of the pigments in the fruit skin. Their blue colour is instead provided by a layer of wax that surrounds the fruit which is made up of miniature structures that scatter blue and UV light. This gives blueberries their blue appearance to humans and blue-UV to birds. The chromatic blue-UV reflectance arises from the interaction of the randomly arranged crystal structures of the epicuticular wax with light.

Tiny external structures in the wax coating of blueberries give them their blue colour, researchers at the University of Bristol can reveal. This applies to lots of fruits that are the same colour including damsons, sloes and juniper berries.

In the study, published in Science Advances, researchers show why blueberries are blue despite the dark red colour of the pigments in the fruit skin. Their blue colour is instead provided by a layer of wax that surrounds the fruit which is made up of miniature structures that scatter blue and UV light. This gives blueberries their blue appearance to humans and blue-UV to birds. The chromatic blue-UV reflectance arises from the interaction of the randomly arranged crystal structures of the epicuticular wax with light.

Rox Middleton, Research Fellow at Bristol’s School of Biological Sciences, explained: “The blue of blueberries can’t be ‘extracted’ by squishing – because it isn’t located in the pigmented juice that can be squeezed from the fruit. That was why we knew that there must be something strange about the colour.

“So we removed the wax and re-crystallised it on card and in doing so we were able to create a brand new blue-UV coating.”

The ultra-thin colourant is around two microns thick, and although less reflective, it’s visibly blue and reflects UV well, possibly paving the way for new colorant methods.

“It shows that nature has evolved to use a really neat trick, an ultrathin layer for an important colorant," added Rox.

Most plants are coated in a thin layer of wax which has multiple functions, many of them that scientists still don’t understand. They know that it can be very effective as a hydrophobic, self-cleaning coating.

However until now, researchers did not know how important the structure was for visible colouration.

Now the team plan to look at easier ways of recreating the coating and applying it. This could lead to a more sustainable, biocompatible and even edible UV and blue-reflective paint.

Furthermore these coatings could have the same multiple functions as natural biological ones that protect plants.

Rox added: “It was really interesting to find that there was an unknown coloration mechanism right under our noses, on popular fruits that we grow and eat all the time.

“It was even more exciting to be able to reproduce that colour by harvesting the wax to make a new blue coating that no-one’s seen before.

“Building all that functionality of this natural wax into artificially engineered materials is the dream!”

Source:

Bristol University

Paper: ‘Self-assembled, Disordered Structural Colour from Fruit Wax Bloom’ by Rox Middleton et al in Science Advances.

(c) RMIT University
26.02.2024

Cooling down with Nanodiamonds

Researchers from RMIT University are using nanodiamonds to create smart textiles that can cool people down faster.

The study found fabric made from cotton coated with nanodiamonds, using a method called electrospinning, showed a reduction of 2-3 degrees Celsius during the cooling down process compared to untreated cotton. They do this by drawing out body heat and releasing it from the fabric – a result of the incredible thermal conductivity of nanodiamonds.

Published in Polymers for Advanced Technologies, project lead and Senior Lecturer, Dr Shadi Houshyar, said there was a big opportunity to use these insights to create new textiles for sportswear and even personal protective clothing, such as underlayers to keep fire fighters cool.

The study also found nanodiamonds increased the UV protection of cotton, making it ideal for outdoor summer clothing.

Researchers from RMIT University are using nanodiamonds to create smart textiles that can cool people down faster.

The study found fabric made from cotton coated with nanodiamonds, using a method called electrospinning, showed a reduction of 2-3 degrees Celsius during the cooling down process compared to untreated cotton. They do this by drawing out body heat and releasing it from the fabric – a result of the incredible thermal conductivity of nanodiamonds.

Published in Polymers for Advanced Technologies, project lead and Senior Lecturer, Dr Shadi Houshyar, said there was a big opportunity to use these insights to create new textiles for sportswear and even personal protective clothing, such as underlayers to keep fire fighters cool.

The study also found nanodiamonds increased the UV protection of cotton, making it ideal for outdoor summer clothing.

“While 2 or 3 degrees may not seem like much of a change, it does make a difference in comfort and health impacts over extended periods and in practical terms, could be the difference between keeping your air conditioner off or turning it on,” Houshyar said. “There’s also potential to explore how nanodiamonds can be used to protect buildings from overheating, which can lead to environmental benefits.”

The use of this fabric in clothing was projected to lead to a 20-30% energy saving due to lower use of air conditioning.

Based in the Centre for Materials Innovation and Future Fashion (CMIFF), the research team is made up of RMIT engineers and textile researchers who have strong expertise in developing next-generation smart textiles, as well as working with industry to develop realistic solutions.

Contrary to popular belief, nanodiamonds are not the same as the diamonds that adorn jewellery, said Houshyar. “They’re actually cheap to make — cheaper than graphene oxide and other types of carbon materials,” she said. “While they have a carbon lattice structure, they are much smaller in size. They’re also easy to make using methods like detonation or from waste materials.”

How it works
Cotton material was first coated with an adhesive, then electrospun with a polymer solution made from nanodiamonds, polyurethane and solvent.

This process creates a web of nanofibres on the cotton fibres, which are then cured to bond the two.

Lead researcher and research assistant, Dr Aisha Rehman, said the coating with nanodiamonds was deliberately applied to only one side of the fabric to restrict heat in the atmosphere from transferring back to the body.  

“The side of the fabric with the nanodiamond coating is what touches the skin. The nanodiamonds then transfer heat from the body into the air,” said Rehman, who worked on the study as part of her PhD. “Because nanodiamonds are such good thermal conductors, it does it faster than untreated fabric.”

Nanodiamonds were chosen for this study because of their strong thermal conductivity properties, said Rehman. Often used in IT, nanodiamonds can also help improve thermal properties of liquids and gels, as well as increase corrosive resistance in metals.

“Nanodiamonds are also biocompatible, so they’re safe for the human body. Therefore, it has great potential not just in textiles, but also in the biomedical field,” Rehman said.

While the research was still preliminary, Houshyar said this method of coating nanofibres onto textiles had strong commercial potential.
 
“This electrospinning approach is straightforward and can significantly reduce the variety of manufacturing steps compared to previously tested methods, which feature lengthy processes and wastage of nanodiamonds,” Houshyar said.

Further research will study the durability of the nanofibres, especially during the washing process.

Source:

Shu Shu Zheng, RMIT University

wind energy Photo: Carlos / Saigon - Vietnam, Pixabay
21.02.2024

Composites' hopes are pinned on wind energy and aviation sectors

Composites Germany - Results of the 22nd Composites Market Survey

  • Critical assessment of the current business situation
  • Future expectations brighten
  • Investment climate remains subdued
  • Different expectations of application industries
  • Growth drivers with slight shifts
  • Composites index points in different directions

For the 22nd time, Composites Germany has collected current key figures on the market for fiber-reinforced plastics. All member companies of the supporting associations of Composites Germany: AVK and Composites United as well as the associated partner VDMA were surveyed.
In order to ensure that the different surveys can be compared without any problems, no fundamental changes were made to the survey. Once again, mainly qualitative data was collected in relation to current and future market developments.

Composites Germany - Results of the 22nd Composites Market Survey

  • Critical assessment of the current business situation
  • Future expectations brighten
  • Investment climate remains subdued
  • Different expectations of application industries
  • Growth drivers with slight shifts
  • Composites index points in different directions

For the 22nd time, Composites Germany has collected current key figures on the market for fiber-reinforced plastics. All member companies of the supporting associations of Composites Germany: AVK and Composites United as well as the associated partner VDMA were surveyed.
In order to ensure that the different surveys can be compared without any problems, no fundamental changes were made to the survey. Once again, mainly qualitative data was collected in relation to current and future market developments.

Critical assessment of the current business situation
After consistently positive trends were seen in the assessment of the current business situation in 2021, this has slipped since 2022. There is still no sign of a trend reversal in the current survey. The reasons for the negative sentiment are manifold and were already evident in the last survey.

At present, politicians do not seem to be able to create a more positive environment for the industry with appropriate measures. Overall, Germany in particular, but also Europe, is currently experiencing a very difficult market environment.

However, the main drivers of the current difficult situation are likely to be the persistently high energy and commodity/raw material prices. In addition, there are still problems in individual areas of the logistics chains, for example on the main trade/container routes, as well as a cautious consumer climate. A slowdown in global trade and uncertainties in the political arena are currently fueling the negative mood in the market.

Despite rising registration figures, the automotive industry, the most important application area for composites, has not yet returned to its former volume. The construction industry, the second most important key area of application, is currently in crisis. Although the order books are still well filled, new orders are often failing to materialize. High interest rates and material costs coupled with the high cost of living are having a particularly negative impact on private construction, but public construction is also currently unable to achieve the targets it has set itself. According to the ZDB (Zentralverband Deutsches Baugewerbe), the forecasts in this important sector remain gloomy: "The decline in the construction industry is continuing. Turnover will fall by 5.3% in real terms this year and we expect a further 3% drop next year. Residential construction remains responsible for the decline, which will slump by 11% in real terms this year and continue its downward trajectory at -13% in 2024."

It is not only the assessment of the general business situation that remains pessimistic. The situation of their own companies also continues to be viewed critically. The picture is particularly negative for Germany. Almost 50% of respondents are critical of the current business situation in Germany. The view of global business and Europe is somewhat more positive. Here, "only" 40% and 35% of respondents respectively assess the situation rather negatively.

Future expectations brighten
Despite the generally rather subdued assessment of the business situation, many of those surveyed appear to be convinced that the mood is improving, at least in Europe. When asked about their assessment of future general business development, the values for Europe and the world are more optimistic than in the last survey. The survey participants do not currently expect the situation in Germany to improve.

Respondents were more optimistic about their own company's future expectations for Europe and the global market.

The participants seem to be assuming a moderate short to medium-term recovery of the global economy. The forecasts are more optimistic than the assessment of the current situation. It is striking that the view of the German region is more critical in relation to Europe and the global economy. 28% of those surveyed expect the general market situation in Germany to develop negatively. Only 13% expect the current situation to improve. The figures for Europe and the world are better.

Investment climate remains subdued
The current rather cautious assessment of the economic situation continues to have an impact on the investment climate.

While 22% of participants in the last survey still assumed an increase in personnel capacity (survey 1/2023 = 40%), this figure is currently only 18%. In contrast, 18% even expect a decrease in personnel.

The proportion of respondents planning to invest in machinery is also declining. While 56% of respondents in the last survey still expected to make such investments, this figure has now fallen to 46%.

Different expectations of application industries
The composites market is characterized by a high degree of heterogeneity in terms of both materials and applications. In the survey, the participants are asked to give their assessment of the market development of different core areas.

The expectations are extremely varied. The two most important application areas are the mobility and construction/infrastructure sectors. Both are currently undergoing major upheavals or are affected by declines, which is also clearly reflected in the survey. Growth is expected above all in the wind energy and aviation sectors.

Growth drivers with slight shifts
In terms of materials, there has been a change in the assessment of growth drivers. While the respondents in the last 9 surveys always named GRP as the material from which the main growth impetus for the composites sector is to be expected, the main impetus is now once again expected to come from CFRP or across all materials.

There is a slight regional shift. Germany is seen less strongly as a growth driver. In contrast, Europe (excluding Germany) and Asia are mentioned significantly more.

Composites index points in different directions
The numerous negative influences of recent times continue to be reflected in the overall Composites Index. This continues to fall, particularly when looking at the current business situation. On the other hand, there is a slight improvement in expectations for future market development, although this remains at a low level.

The total volume of processed composites in Europe in 2022 was already declining, and a further decline must also be expected for 2023. This is likely to be around 5% again.

It remains to be seen whether it will be possible to counteract the negative trend. Targeted intervention, including by political decision-makers, would be desirable here. However, this cannot succeed without industry/business. Only together will it be possible to maintain and strengthen Germany as a business/industry location. For composites as a material group in general, there are still very good opportunities to expand the market position in both new and existing markets due to the special portfolio of properties. However, the dependency on macroeconomic developments remains. It is now important to develop new market areas through innovation, to consistently exploit opportunities and to work together to further implement composites in existing markets. This can often be achieved better together than alone. With its excellent network, Composites Germany offers a wide range of opportunities.

The next composites market survey will be published in July 2024.

Source:

Composites Germany

Wearable Robots for Parkinson’s Disease Image: Tom Claes, unsplash
19.02.2024

Wearable Robots for Parkinson’s Disease

Freezing is one of the most common and debilitating symptoms of Parkinson’s disease, a neurodegenerative disorder that affects more than 9 million people worldwide. When individuals with Parkinson’s disease freeze, they suddenly lose the ability to move their feet, often mid-stride, resulting in a series of staccato stutter steps that get shorter until the person stops altogether. These episodes are one of the biggest contributors to falls among people living with Parkinson’s disease.

Today, freezing is treated with a range of pharmacological, surgical or behavioral therapies, none of which are particularly effective. What if there was a way to stop freezing altogether?

Freezing is one of the most common and debilitating symptoms of Parkinson’s disease, a neurodegenerative disorder that affects more than 9 million people worldwide. When individuals with Parkinson’s disease freeze, they suddenly lose the ability to move their feet, often mid-stride, resulting in a series of staccato stutter steps that get shorter until the person stops altogether. These episodes are one of the biggest contributors to falls among people living with Parkinson’s disease.

Today, freezing is treated with a range of pharmacological, surgical or behavioral therapies, none of which are particularly effective. What if there was a way to stop freezing altogether?

Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and the Boston University Sargent College of Health & Rehabilitation Sciences have used a soft, wearable robot to help a person living with Parkinson’s walk without freezing. The robotic garment, worn around the hips and thighs, gives a gentle push to the hips as the leg swings, helping the patient achieve a longer stride.

The device completely eliminated the participant’s freezing while walking indoors, allowing them to walk faster and further than they could without the garment’s help.

“We found that just a small amount of mechanical assistance from our soft robotic apparel delivered instan-taneous effects and consistently improved walking across a range of conditions for the individual in our study,” said Conor Walsh, the Paul A. Maeder Professor of Engineering and Applied Sciences at SEAS and co-corresponding author of the study.

The research demonstrates the potential of soft robotics to treat this frustrating and potentially dangerous symptom of Parkinson’s disease and could allow people living with the disease to regain not only their mobility but their independence.

For over a decade, Walsh’s Biodesign Lab at SEAS has been developing assistive and rehabilitative robotic technologies to improve mobility for individuals’ post-stroke and those living with ALS or other diseases that impact mobility. Some of that technology, specifically an exosuit for post-stroke gait retraining, received support from the Wyss Institute for Biologically Inspired Engineering, and Harvard’s Office of Technology Development coordinated a license agreement with ReWalk Robotics to commercialize the technology.

In 2022, SEAS and Sargent College received a grant from the Massachusetts Technology Collaborative to support the development and translation of next-generation robotics and wearable technologies. The research is centered at the Move Lab, whose mission is to support advances in human performance enhancement with the collaborative space, funding, R&D infrastructure, and experience necessary to turn promising research into mature technologies that can be translated through collaboration with industry partners. This research emerged from that partnership.

“Leveraging soft wearable robots to prevent freezing of gait in patients with Parkinson’s required a collaboration between engineers, rehabilitation scientists, physical therapists, biomechanists and apparel designers,” said Walsh, whose team collaborated closely with that of Terry Ellis,  Professor and Physical Therapy Department Chair and Director of the Center for Neurorehabilitation at Boston University.

Leveraging soft wearable robots to prevent freezing of gait in patients with Parkinson’s required a collaboration between engineers, rehabilitation scientists, physical therapists, biomechanists and apparel designers.

The team spent six months working with a 73-year-old man with Parkinson’s disease, who — despite using both surgical and pharmacologic treatments — endured substantial and incapacitating freezing episodes more than 10 times a day, causing him to fall frequently. These episodes prevented him from walking around his community and forced him to rely on a scooter to get around outside.

In previous research, Walsh and his team leveraged human-in-the-loop optimization to demonstrate that a soft, wearable device could be used to augment hip flexion and assist in swinging the leg forward to provide an efficient approach to reduce energy expenditure during walking in healthy individuals.

Here, the researchers used the same approach but to address freezing. The wearable device uses cable-driven actuators and sensors worn around the waist and thighs. Using motion data collected by the sensors, algorithms estimate the phase of the gait and generate assistive forces in tandem with muscle movement.

The effect was instantaneous. Without any special training, the patient was able to walk without any freezing indoors and with only occasional episodes outdoors. He was also able to walk and talk without freezing, a rarity without the device.

“Our team was really excited to see the impact of the technology on the participant’s walking,” said Jinsoo Kim, former PhD student at SEAS and co-lead author on the study.

During the study visits, the participant told researchers: “The suit helps me take longer steps and when it is not active, I notice I drag my feet much more. It has really helped me, and I feel it is a positive step forward. It could help me to walk longer and maintain the quality of my life.”

“Our study participants who volunteer their time are real partners,” said Walsh. “Because mobility is difficult, it was a real challenge for this individual to even come into the lab, but we benefited so much from his perspective and feedback.”

The device could also be used to better understand the mechanisms of gait freezing, which is poorly understood.

“Because we don’t really understand freezing, we don’t really know why this approach works so well,” said Ellis. “But this work suggests the potential benefits of a ’bottom-up’ rather than ’top-down’ solution to treating gait freezing. We see that restoring almost-normal biomechanics alters the peripheral dynamics of gait and may influence the central processing of gait control.”

The research was co-authored by Jinsoo Kim, Franchino Porciuncula, Hee Doo Yang, Nicholas Wendel, Teresa Baker and Andrew Chin. Asa Eckert-Erdheim and Dorothy Orzel also contributed to the design of the technology, as well as Ada Huang, and Sarah Sullivan managed the clinical research. It was supported by the National Science Foundation under grant CMMI-1925085; the National Institutes of Health under grant NIH U01 TR002775; and the Massachusetts Technology Collaborative, Collaborative Research and Development Matching Grant.

Source:

The research is published in Nature Medicine.
Source Leah Burrows
Harvard John A. Paulson. School of Engineering and Applied Sciences

Researchers led by Bernd Nowack have investigated the release of nanoparticles during the washing of polyester textiles. Image: Empa Image: Empa
14.02.2024

Release of oligomers from polyester textiles

When nanoplastics are not what they seem ... Textiles made of synthetic fibers release micro- and nanoplastics during washing. Empa researchers have now been able to show: Some of the supposed nanoplastics do not actually consist of plastic particles, but of water-insoluble oligomers. The effects they have on humans and the environment are not yet well-understood.

Plastic household items and clothing made of synthetic fibers release microplastics: particles less than five millimetres in size that can enter the environment unnoticed. A small proportion of these particles are so small that they are measured in nanometers. Such nanoplastics are the subject of intensive research, as nanoplastic particles can be absorbed into the human body due to their small size – but, as of today, little is known about their potential toxicity.

When nanoplastics are not what they seem ... Textiles made of synthetic fibers release micro- and nanoplastics during washing. Empa researchers have now been able to show: Some of the supposed nanoplastics do not actually consist of plastic particles, but of water-insoluble oligomers. The effects they have on humans and the environment are not yet well-understood.

Plastic household items and clothing made of synthetic fibers release microplastics: particles less than five millimetres in size that can enter the environment unnoticed. A small proportion of these particles are so small that they are measured in nanometers. Such nanoplastics are the subject of intensive research, as nanoplastic particles can be absorbed into the human body due to their small size – but, as of today, little is known about their potential toxicity.

Empa researchers from Bernd Nowack's group in the Technology and Society laboratory have now joined forces with colleagues from China to take a closer look at nanoparticles released from textiles. Tong Yang, first author of the study, carried out the investigations during his doctorate at Empa. In earlier studies, Empa researchers were already able to demonstrate that both micro- and nanoplastics are released when polyester is washed. A detailed examination of the released nanoparticles released has now shown that not everything that appears to be nanoplastic at first glance actually is nanoplastic.

To a considerable extent, the released particles were in fact not nanoplastics, but clumps of so-called oligomers, i.e. small to medium-sized molecules that represent an intermediate stage between the long-chained polymers and their individual building blocks, the monomers. These molecules are even smaller than nanoplastic particles, and hardly anything is known about their toxicity either. The researchers published their findings in the journal Nature Water.

For the study, the researchers examined twelve different polyester fabrics, including microfiber, satin and jersey. The fabric samples were washed up to four times and the nanoparticles released in the process were analyzed and characterized. Not an easy task, says Bernd Nowack. "Plastic, especially nanoplastics, is everywhere, including on our devices and utensils," says the scientist. "When measuring nanoplastics, we have to take this 'background noise' into account."

Large proportion of soluble particles
The researchers used an ethanol bath to distinguish nanoplastics from clumps of oligomers. Plastic pieces, no matter how small, do not dissolve in ethanol, but aggregations of oligomers do. The result: Around a third to almost 90 percent of the nanoparticles released during washing could be dissolved in ethanol. "This allowed us to show that not everything that looks like nanoplastics at first glance is in fact nanoplastics," says Nowack.

It is not yet clear whether the release of so-called nanoparticulate oligomers during the washing of textiles has negative effects on humans and the environment. "With other plastics, studies have already shown that nanoparticulate oligomers are more toxic than nanoplastics," says Nowack. "This is an indication that this should be investigated more closely." However, the researchers were able to establish that the nature of the textile and the cutting method – scissors or laser – have no major influence on the quantity of particles released.

The mechanism of release has not been clarified yet either – neither for nanoplastics nor for the oligomer particles. The good news is that the amount of particles released decreases significantly with repeated washes. It is conceivable that the oligomer particles are created during the manufacturing of the textile or split off from the fibers through chemical processes during storage. Further studies are also required in this area.

Nowack and his team are focusing on larger particles for the time being: In their next project, they want to investigate which fibers are released during washing of textiles made from renewable raw materials and whether these could be harmful to the environment and health. "Semi-synthetic textiles such as viscose or lyocell are being touted as a replacement for polyester," says Nowack. "But we don't yet know whether they are really better when it comes to releasing fibers."

Source:

Empa

Photo: TheDigitalArtist, Pixabay
31.01.2024

“Smart nanocomposites” for wearable electronics, vehicles, and buildings

  • Small, lightweight, stretchable, cost-efficient thermoelectric devices signify a breakthrough in sustainable energy development and waste heat recovery.
  • Next-gen flexible energy harvesting systems will owe their efficiency to the integration of graphene nanotubes. They offer easy processability, stable thermoelectric performance, flexibility, and robust mechanical properties.
  • Nanocomposites have high market potential in manufacturing generators for medical and smart wearables, vehicles sensors, and efficient building management.

Around half of the world’s useful energy is wasted as heat due to the limited efficiency of energy conversion devices. For example, one-third of a vehicle’s energy dissipates as waste heat in exhaust gases. At the same time, vehicles contain more and more electronic devices requiring electrical energy.

  • Small, lightweight, stretchable, cost-efficient thermoelectric devices signify a breakthrough in sustainable energy development and waste heat recovery.
  • Next-gen flexible energy harvesting systems will owe their efficiency to the integration of graphene nanotubes. They offer easy processability, stable thermoelectric performance, flexibility, and robust mechanical properties.
  • Nanocomposites have high market potential in manufacturing generators for medical and smart wearables, vehicles sensors, and efficient building management.

Around half of the world’s useful energy is wasted as heat due to the limited efficiency of energy conversion devices. For example, one-third of a vehicle’s energy dissipates as waste heat in exhaust gases. At the same time, vehicles contain more and more electronic devices requiring electrical energy. As another example, lightweight wearable sensors for health and environmental monitoring are also becoming increasingly demanding. The potential to convert waste heat or solar energy into useful electrical power has emerged as an opportunity for more sustainable energy management. Convenient thermoelectric generators (TEGs) currently have only low effectiveness and a relatively large size and weight. Based on expensive or corrosion-vulnerable materials, they are rigid and often contain toxic elements.
 
Recently developed, easy-to-process, self-supporting and flexible nonwoven nanocomposite sheets demonstrate excellent thermoelectric properties combined with good mechanical robustness. A recent paper in ACS Applied Nano Materials described how researches combined a thermoplastic polyurethane (TPU) with TUBALLTM graphene nanotubes to fabricate a nanocomposite material capable of harvesting electrical energy from sources of waste heat.

Thanks to their high aspect ratio and specific surface area, graphene nanotubes provide TPU with electrical conductivity, making it possible to achieve high thermoelectrical performance while maintaining or improving mechanical properties. “Stiffness, strength, and tensile toughness were improved by 7, 25, and 250 times compared to buckypapers, respectively. Nanocomposite sheet shows low electrical resistivity of 7.5*10-3 Ohm×cm, high Young’s modulus of 1.8 GPa, failure strength of 80 MPa, and elongation at break of 41%,” said Dr. Beate Krause, Group Leader, Leibniz-Institut für Polymerforschung Dresden e. V.

Graphene nanotubes, being a fundamentally new material, provide an opportunity to replace current TEG materials with more environmentally friendly ones. The sensors powered by such thermoelectric generators could act as a “smart skin” for vehicles and buildings, providing sensoring capabilities to monitor performance and prevent potential issues before they lead to breakdowns, ensuring optimal operational efficiency. In aircraft, no-wire nanocomposites could serve as stand-alone sensors for monitoring deicing systems, eliminating the need for an extensive network of electrical cables. The high flexibility, strength, and reliability of graphene nanotube-enabled thermoelectric materials also extend their applications into the realm of smart wearable and medical devices.

Source:

Leibniz-Institut für Polymerforschung Dresden e. V. / OCSiAl

Photo: Sibi Suku, unsplash
29.01.2024

Naturalistic silk spun from artificial spider gland

Researchers led by Keiji Numata at the RIKEN Center for Sustainable Resource Science in Japan, along with colleagues from the RIKEN Pioneering Research Cluster, have succeeded in creating a device that spins artificial spider silk that closely matches what spiders naturally produce. The artificial silk gland was able to re-create the complex molecular structure of silk by mimicking the various chemical and physical changes that naturally occur in a spider’s silk gland. This eco-friendly innovation is a big step towards sustainability and could impact several industries. This study was published January 15 in the scientific journal Nature Communications.

Researchers led by Keiji Numata at the RIKEN Center for Sustainable Resource Science in Japan, along with colleagues from the RIKEN Pioneering Research Cluster, have succeeded in creating a device that spins artificial spider silk that closely matches what spiders naturally produce. The artificial silk gland was able to re-create the complex molecular structure of silk by mimicking the various chemical and physical changes that naturally occur in a spider’s silk gland. This eco-friendly innovation is a big step towards sustainability and could impact several industries. This study was published January 15 in the scientific journal Nature Communications.

Famous for its strength, flexibility, and light weight, spider silk has a tensile strength that is comparable to steel of the same diameter, and a strength to weight ratio that is unparalleled. Added to that, it’s biocompatible, meaning that it can be used in medical applications, as well as biodegradable. So why isn’t everything made from spider silk? Large-scale harvesting of silk from spiders has proven impractical for several reasons, leaving it up to scientists to develop a way to produce it in the laboratory.

Spider silk is a biopolymer fiber made from large proteins with highly repetitive sequences, called spidroins. Within the silk fibers are molecular substructures called beta sheets, which must be aligned properly for the silk fibers to have their unique mechanical properties. Re-creating this complex molecular architecture has confounded scientists for years. Rather than trying to devise the process from scratch, RIKEN scientists took a biomimicry approach. As Numata explains, “in this study, we attempted to mimic natural spider silk production using microfluidics, which involves the flow and manipulation of small amounts of fluids through narrow channels. Indeed, one could say that that the spider’s silk gland functions as a sort of natural microfluidic device.”

The device developed by the researchers looks like a small rectangular box with tiny channels grooved into it. Precursor spidroin solution is placed at one end and then pulled towards the other end by means of negative pressure. As the spidroins flow through the microfluidic channels, they are exposed to precise changes in the chemical and physical environment, which are made possible by the design of the microfluidic system. Under the correct conditions, the proteins self-assembled into silk fibers with their characteristic complex structure.

The researchers experimented to find these correct conditions, and eventually were able to optimize the interactions among the different regions of the microfluidic system. Among other things, they discovered that using force to push the proteins through did not work; only when they used negative pressure to pull the spidroin solution could continuous silk fibers with the correct telltale alignment of beta sheets be assembled.

“It was surprising how robust the microfluidic system was, once the different conditions were established and optimized,” says Senior Scientist Ali Malay, one of the paper’s co-authors. “Fiber assembly was spontaneous, extremely rapid, and highly reproducible. Importantly, the fibers exhibited the distinct hierarchical structure that is found in natural silk fiber.”

The ability to artificially produce silk fibers using this method could provide numerous benefits. Not only could it help reduce the negative impact that current textile manufacturing has on the environment, but the biodegradable and biocompatible nature of spider silk makes it ideal for biomedical applications, such as sutures and artificial ligaments.

“Ideally, we want to have a real-world impact,” says Numata. “For this to occur, we will need to scale-up our fiber-production methodology and make it a continuous process. We will also evaluate the quality of our artificial spider silk using several metrics and make further improvements from there.”

Source:

RIKEN Center for Sustainable Resource Science, Japan

Converting CO2 to Solid Carbon Nanofibers (c) Zhenhua Xie/Brookhaven National Laboratory and Columbia University; Erwei Huang/Brookhaven National Laboratory
22.01.2024

Converting CO2 to Solid Carbon Nanofibers

Tandem electrocatalytic-thermocatalytic conversion could help offset emissions of potent greenhouse gas by locking carbon away in a useful material.

Scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory and Columbia University have developed a way to convert carbon dioxide (CO2), a potent greenhouse gas, into carbon nanofibers, materials with a wide range of unique properties and many potential long-term uses. Their strategy uses tandem electrochemical and thermochemical reactions run at relatively low temperatures and ambient pressure. As the scientists describe in the journal Nature Catalysis, this approach could successfully lock carbon away in a useful solid form to offset or even achieve negative carbon emissions.

Tandem electrocatalytic-thermocatalytic conversion could help offset emissions of potent greenhouse gas by locking carbon away in a useful material.

Scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory and Columbia University have developed a way to convert carbon dioxide (CO2), a potent greenhouse gas, into carbon nanofibers, materials with a wide range of unique properties and many potential long-term uses. Their strategy uses tandem electrochemical and thermochemical reactions run at relatively low temperatures and ambient pressure. As the scientists describe in the journal Nature Catalysis, this approach could successfully lock carbon away in a useful solid form to offset or even achieve negative carbon emissions.

“You can put the carbon nanofibers into cement to strengthen the cement,” said Jingguang Chen, a professor of chemical engineering at Columbia with a joint appointment at Brookhaven Lab who led the research. “That would lock the carbon away in concrete for at least 50 years, potentially longer. By then, the world should be shifted to primarily renewable energy sources that don’t emit carbon.”

As a bonus, the process also produces hydrogen gas (H2), a promising alternative fuel that, when used, creates zero emissions.

Capturing or converting carbon?
The idea of capturing CO2 or converting it to other materials to combat climate change is not new. But simply storing CO2 gas can lead to leaks. And many CO2 conversions produce carbon-based chemicals or fuels that are used right away, which releases CO2 right back into the atmosphere.

“The novelty of this work is that we are trying to convert CO2 into something that is value-added but in a solid, useful form,” Chen said.

Such solid carbon materials—including carbon nanotubes and nanofibers with dimensions measuring billionths of a meter—have many appealing properties, including strength and thermal and electrical conductivity. But it’s no simple matter to extract carbon from carbon dioxide and get it to assemble into these fine-scale structures. One direct, heat-driven process requires temperatures in excess of 1,000 degrees Celsius.

“It’s very unrealistic for large-scale CO2 mitigation,” Chen said. “In contrast, we found a process that can occur at about 400 degrees Celsius, which is a much more practical, industrially achievable temperature.”

The tandem two-step
The trick was to break the reaction into stages and to use two different types of catalysts—materials that make it easier for molecules to come together and react.

“If you decouple the reaction into several sub-reaction steps you can consider using different kinds of energy input and catalysts to make each part of the reaction work,” said Brookhaven Lab and Columbia research scientist Zhenhua Xie, lead author on the paper.

The scientists started by realizing that carbon monoxide (CO) is a much better starting material than CO2 for making carbon nanofibers (CNF). Then they backtracked to find the most efficient way to generate CO from CO2.

Earlier work from their group steered them to use a commercially available electrocatalyst made of palladium supported on carbon. Electrocatalysts drive chemical reactions using an electric current. In the presence of flowing electrons and protons, the catalyst splits both CO2 and water (H2O) into CO and H2.

For the second step, the scientists turned to a heat-activated thermocatalyst made of an iron-cobalt alloy. It operates at temperatures around 400 degrees Celsius, significantly milder than a direct CO2-to-CNF conversion would require. They also discovered that adding a bit of extra metallic cobalt greatly enhances the formation of the carbon nanofibers.

“By coupling electrocatalysis and thermocatalysis, we are using this tandem process to achieve things that cannot be achieved by either process alone,” Chen said.

Catalyst characterization
To discover the details of how these catalysts operate, the scientists conducted a wide range of experiments. These included computational modeling studies, physical and chemical characterization studies at Brookhaven Lab’s National Synchrotron Light Source II (NSLS-II)—using the Quick X-ray Absorption and Scattering (QAS) and Inner-Shell Spectroscopy (ISS) beamlines—and microscopic imaging at the Electron Microscopy facility at the Lab’s Center for Functional Nanomaterials (CFN).

On the modeling front, the scientists used “density functional theory” (DFT) calculations to analyze the atomic arrangements and other characteristics of the catalysts when interacting with the active chemical environment.

“We are looking at the structures to determine what are the stable phases of the catalyst under reaction conditions,” explained study co-author Ping Liu of Brookhaven’s Chemistry Division who led these calculations. “We are looking at active sites and how these sites are bonding with the reaction intermediates. By determining the barriers, or transition states, from one step to another, we learn exactly how the catalyst is functioning during the reaction.”

X-ray diffraction and x-ray absorption experiments at NSLS-II tracked how the catalysts change physically and chemically during the reactions. For example, synchrotron x-rays revealed how the presence of electric current transforms metallic palladium in the catalyst into palladium hydride, a metal that is key to producing both H2 and CO in the first reaction stage.

For the second stage, “We wanted to know what’s the structure of the iron-cobalt system under reaction conditions and how to optimize the iron-cobalt catalyst,” Xie said. The x-ray experiments confirmed that both an alloy of iron and cobalt plus some extra metallic cobalt are present and needed to convert CO to carbon nanofibers.

“The two work together sequentially,” said Liu, whose DFT calculations helped explain the process.

“According to our study, the cobalt-iron sites in the alloy help to break the C-O bonds of carbon monoxide. That makes atomic carbon available to serve as the source for building carbon nanofibers. Then the extra cobalt is there to facilitate the formation of the C-C bonds that link up the carbon atoms,” she explained.

Recycle-ready, carbon-negative
“Transmission electron microscopy (TEM) analysis conducted at CFN revealed the morphologies, crystal structures, and elemental distributions within the carbon nanofibers both with and without catalysts,” said CFN scientist and study co-author Sooyeon Hwang.

The images show that, as the carbon nanofibers grow, the catalyst gets pushed up and away from the surface. That makes it easy to recycle the catalytic metal, Chen said.

“We use acid to leach the metal out without destroying the carbon nanofiber so we can concentrate the metals and recycle them to be used as a catalyst again,” he said.

This ease of catalyst recycling, commercial availability of the catalysts, and relatively mild reaction conditions for the second reaction all contribute to a favorable assessment of the energy and other costs associated with the process, the researchers said.

“For practical applications, both are really important—the CO2 footprint analysis and the recyclability of the catalyst,” said Chen. “Our technical results and these other analyses show that this tandem strategy opens a door for decarbonizing CO2 into valuable solid carbon products while producing renewable H2.”

If these processes are driven by renewable energy, the results would be truly carbon-negative, opening new opportunities for CO2 mitigation.

Source:

Brookhaven National Laboratory

Photo: Walmart Inc.
15.01.2024

What is a Virtual Fitting Room? Advantages and Early Adopters

One of the major concerns of online shopping is a consumer’s inability to touch, feel and experience products. This concern is more problematic for fashion products, when the right fit is critical for purchase decisions. Virtual Fitting Room (VFR), a technology that allows consumers to test size and fit without having to try clothing on themselves, eases this concern.

What is a Virtual Fitting Room (VFR)?
A Virtual Fitting Room (VFR) is a function that shows and visualizes a shopper’s outfit without physically trying on and touching items. VFR utilizes Augmented Reality (AR) and Artificial Intelligence (AI). By using AR for VFR, a webcam scans the body shape of shoppers and creates a 360-degree, 3D model based on their body shape.

One of the major concerns of online shopping is a consumer’s inability to touch, feel and experience products. This concern is more problematic for fashion products, when the right fit is critical for purchase decisions. Virtual Fitting Room (VFR), a technology that allows consumers to test size and fit without having to try clothing on themselves, eases this concern.

What is a Virtual Fitting Room (VFR)?
A Virtual Fitting Room (VFR) is a function that shows and visualizes a shopper’s outfit without physically trying on and touching items. VFR utilizes Augmented Reality (AR) and Artificial Intelligence (AI). By using AR for VFR, a webcam scans the body shape of shoppers and creates a 360-degree, 3D model based on their body shape.

AI further operates VFR by using algorithms and machine learning to design a full-body 3D model of a shopper standing in front of the camera. A combination of AR and AI technology allows VFR to place items on real-time images as a live video so that customers can check the size, style and fit of the products they’re considering purchasing.

Shoppers can try on clothes and shoes at home without visiting a physical store. In order to do this, customers need to first make sure they have the right settings on their phone. Then, they download a brands’ mobile applications with the Virtual Fitting Room function or visit apparel brands’ websites that support this VFR function and upload a photo of their body shape. Some brands allow a customer to create an avatar using their body shape to test out the fashion items virtually, instead of uploading a photo of themselves.

How does using a Virtual Fitting Room benefit fashion retailers?

  • Provides a convenient shopping experience
    Research conducted by the National Retail Federation in 2020 stated that 97% of consumers have ended a shopping trip or stopped searching for the item they had in mind because the process was inconvenient.
    Shoppers surveyed not only said that in-person shopping was inconvenient but that online shopping felt even more inconvenient to them.
    VFR eliminates all of these processes. Shoppers can walk over to the VFR and see what the clothes look like quickly without needing to change them.
     
  • Overcomes the limitations of online shopping
    As of 2017, 62% of shoppers preferred to shop at physical apparel stores because they could see, touch, feel and experience products. This was a major problem that online shopping could not overcome.
    VFR solves this problem effectively. According to a Retail Perceptions Report, about 40% of buyers said they would be willing to pay more if they could experience the product through AR technology. By incorporating new technologies, VFR makes shopping fun and offers a personalized shopping experience to customers, which can attract more people to online channels.
     
  • Reduces the return rate
    High return rates are a big administrative headache for fashion brands. Moreover, it threatens to cut into the profits of fashion brands if they offer free returns. 30% of the return rate in e-commerce fashion shopping is due to purchases of small-sized products, and another 22% happens due to purchases of too large-sized products.
    However, VFR alleviates this problem. Whether in store or online, people can check the fit and size of items without having to wear them themselves.

Which brands are already using Virtual Fitting Room (VFR) technology?
Gucci

Gucci is the first luxury brand which adopted VFR. They partnered with Snapchat to launch an augmented reality shoe try-on campaign. It created a virtual lens that superimposed and overlaid a digital version of the shoe on the shopper’s foot when the foot was photographed using a cell phone camera.

Along with the Shop Now button, which guides shoppers to its online store, Gucci achieved 18.9 million Snapchat users and reported positive return on ad spend, which is a marketing metric that measures the amount of revenue earned on all dollars spent on advertising from this campaign.

Otero Menswear
Otero Menswear is a brand focused on apparel for men shorter than 5’10” (1,78 m). Otero added VFR software to its online store to provide perfect fitting sizes to its customers. First, it asks customers four quick questions about their height, leg length, waist size and body type. Then, it offers a virtual avatar corresponding with the answers. Shoppers then use this avatar to see how different sizes of Otero clothing would look on them.
 
Walmart
In May 2021, Walmart announced that they plan to acquire Zeekit, a virtual fitting room platform, to provide enhanced and social shopping experiences for customers during the pandemic.

When customers upload pictures of themselves and enter their body dimensions, Zeekit builds a virtual body and then customers can dress it accordingly. Customers will simply post their photos or choose virtual models on the platform that represent the best fitting of their height, body and skin tone. Shoppers can even share their virtual clothes with others to get various opinions. Walmart brings a comprehensive and social experience to digital shopping for customers through this acquisition of VFR.

According to research by Valuates Reports, it is expected that sales of the global virtual fitting room market will grow to $6.5 million by 2025. By adopting VFR, consumers will be able to experience convenience in an advanced shopping environment. At the same time, fashion retailers will be able to increase online sales and reduce return rates by offering customers personalized online shopping experiences using VFR technology.

Source:

Heekyeong Jo and B. Ellie Jin
This article was originally published by members of the Wilson College of Textiles’ Fashion Textile and Business Excellence Cooperative.

Bakery Pexels at Pixabay
08.01.2024

BakeTex: Textile baking mat supports bakeries in saving energy

The ongoing energy crisis is increasingly pushing the bakery trade to its limits. Bakeries everywhere are having to close because they can no longer afford the sharp rise in the cost of electricity and gas. The use of energy-efficient ovens and the optimisation of production processes are important components that help to save energy. Researchers at the Fraunhofer Application Centre for Textile Fibre Ceramics TFK in Münchberg have now developed another building block: a textile baking base.
 
In bakeries, trays are normally used as a base for the baked goods in combination with baking paper or flour, which not only leads to large amounts of waste, but also to health problems (baker's asthma). The baking trays are also heavy and their mass increases the energy consumption in the oven, as they have to be heated with every baking process.

The ongoing energy crisis is increasingly pushing the bakery trade to its limits. Bakeries everywhere are having to close because they can no longer afford the sharp rise in the cost of electricity and gas. The use of energy-efficient ovens and the optimisation of production processes are important components that help to save energy. Researchers at the Fraunhofer Application Centre for Textile Fibre Ceramics TFK in Münchberg have now developed another building block: a textile baking base.
 
In bakeries, trays are normally used as a base for the baked goods in combination with baking paper or flour, which not only leads to large amounts of waste, but also to health problems (baker's asthma). The baking trays are also heavy and their mass increases the energy consumption in the oven, as they have to be heated with every baking process.

With this in mind, the Bavarian Research Foundation approved a research project in 2021 to develop an alternative to conventional baking trays, which was successfully completed in 2023. The project partners were the Fraunhofer Application Centre for Textile Fibre Ceramics TFK from Münchberg, Fickenschers Backhaus GmbH from Münchberg and Weberei Wilhelm Zuleeg GmbH from Helmbrechts.

The aim of the project was to develop an energy-saving, pollutant-free and reusable textile baking mat with an integrated non-stick effect for use in industrial bakeries. Lightweight and heat-resistant textiles offer the potential to lower the preheating temperature in the oven and thus reduce energy consumption.
 
In a first step, a thin para-aramid fabric made of 120 g/m² long staple fibre yarn was therefore produced and stretched on a metallic frame. "The leno weave proved to be particularly suitable for the weave. Its characteristic lattice structure ensures that the textile is not only light but also permeable to air," says Silke Grosch from the Fraunhofer Application Centre TFK.

"In addition, by fixing the threads in place, the fabric cannot warp during washing and retains its shape for a long time." Finally, a full-surface silicone coating ensures that the baked goods do not stick to the baking base. This means that the previously necessary baking paper and flour layer can be dispensed with. To ensure that the rolls come out of the oven just as crispy and brown as with a standard baking tray, only the baking programme needs to be adjusted. Another key advantage of the textile baking tray is that it can be folded and therefore stored in a space-saving manner.

In the course of the fourth industrial revolution (Industry 4.0), the baking tray will be equipped with intelligent additional functions. On the one hand, the production data in the bakery can be determined using RFID chips or QR codes, and on the other hand, baked goods can be advertised in a targeted manner using customised branding.

Prof. Dr Frank Ficker, Head of the Fraunhofer Application Centre TFK, sums up: "With the textile baking base, we have developed a contemporary and resource-saving product together with our project partners that is characterised by its low weight and high flexibility. Together with the potential energy savings, this makes it interesting for many bakeries."

The Fraunhofer Application Centre for Textile Fibre Ceramics TFK in Münchberg specialises in the development, manufacture and testing of textile ceramic components. It is part of the Fraunhofer Centre for High Temperature Lightweight Construction HTL in Bayreuth, a facility of the Fraunhofer Institute for Silicate Research ISC with headquarters in Würzburg.

Source:

Fraunhofer Application Centre for Textile Fibre Ceramics
Translation Textination

Better Manufacturing Method for Wound Closures (c) Wilson College of Textiles
03.01.2024

Better Manufacturing Method for Wound Closures

If you’ve ever gotten stitches or had surgery, you may have had a suture. They’re the threads used to close wounds or join tissues together for other purposes.

But did you know that there are different types of sutures which can have an effect on your experience at the doctor or surgeon’s office?

Barbed sutures, for example, can reduce the amount of time you spend on the operating table and lower the likelihood of surgical complications. That type of suture has its roots in the Triangle and is being advanced by students and faculty at the Wilson College of Textiles.

Dr. Gregory Ruff, a nationally-renowned plastic surgeon, first invented the innovative closure in 1991, just down the road in Chapel Hill, North Carolina.

“I was thinking about the fact that we sew wounds together with a loop and a knot and if you tie it too tight, it can constrict the circulation and kill the tissue in that loop,” Dr. Ruff remembers.

If you’ve ever gotten stitches or had surgery, you may have had a suture. They’re the threads used to close wounds or join tissues together for other purposes.

But did you know that there are different types of sutures which can have an effect on your experience at the doctor or surgeon’s office?

Barbed sutures, for example, can reduce the amount of time you spend on the operating table and lower the likelihood of surgical complications. That type of suture has its roots in the Triangle and is being advanced by students and faculty at the Wilson College of Textiles.

Dr. Gregory Ruff, a nationally-renowned plastic surgeon, first invented the innovative closure in 1991, just down the road in Chapel Hill, North Carolina.

“I was thinking about the fact that we sew wounds together with a loop and a knot and if you tie it too tight, it can constrict the circulation and kill the tissue in that loop,” Dr. Ruff remembers.

“I was thinking about animals, and a porcupine’s quill came to mind. And the aha moment was, ‘What if we put a quill on one side of the wound and another one on the other side of the wound, so there’s no loop: the barbs go in but they don’t come out?’”

As the name suggests, barbed sutures have small projections shooting out of them that can latch onto tissues: think about barbed wire or a fishing hook. Those “quills,” or barbs, allow the suture to self-anchor. Since no knot is needed to secure the suture, the closure is faster, and the lack of knots and constricting loops promotes healing. This also allows surgeons to schedule more surgeries.

Soon after his aha moment, Dr. Ruff started his own company, Quill Medical, to fabricate these barbed sutures. While he had the medical expertise and a solid business partner, Dr. Ruff was looking for someone who could advise him in terms of the material makeup of the suture. The Wilson College’s Biomedical Textile Research Group, under the direction of Professor Martin King, quickly proved to be the perfect partner.

Using the Wilson College’s labs, King’s graduate students conducted a number of tests on Ruff’s sutures across different types of tissues (such as skin, muscle, etc.). One of those students, Nilesh Ingle, found that the barbed sutures worked best when the angles of the barbs were tailored specifically to the type of tissue being sutured.

Years later, one of King’s current graduate students is building on that research insight.
 
Understanding challenges and innovating solutions
Nearly three decades after the barbed suture’s invention, the majority of surgeons still use conventional sutures despite the advantages documented by researchers and surgeons. Why?

Karuna Nambi Gowri, a fiber and polymer science doctoral student in King’s research group, says it comes down to two reasons. The first of these is resistance to change. Most practicing surgeons learned how to use a suture before barbed sutures became more broadly available.

The second obstacle to the use of barbed sutures is procuring them. Barbed sutures tend to be both expensive and low in supply. That’s because the current process for making them (mechanical and blade-based) is inefficient in terms of both time and resources.

That’s where Nambi Gowri’s research with the Wilson College’s Biomedical Textiles Research Group comes in. She’s developing a faster and cheaper method for making the same quality of barbed suture.

“If I fabricate using a laser, the fabrication time is pretty short compared to a mechanical barbing technique,” Nambi Gowri says.

Moving from a mechanical method to a laser method has another advantage.

“The manipulation of the barbed suture itself is easier using a laser,” she says.

In other words, using the lasers will allow Nambi Gowri to apply the custom barb geometries, or angles, suggested by prior researchers on a commercial scale. These custom geometries will allow the barbed suture to be optimized for the type of tissue it will be connecting.

In addition to the new process, Nambi Gowri is also developing a new suture.

“I’m the first one to actually study Catgut barbed sutures,” she explains.

Catgut was actually one of the earliest materials used to make sutures. The filament is made from tissue taken from an animal’s stomach – especially cattle stomachs – hence the name. While the industry had moved away from this material in favor of synthetic polymers, Nambi Gowri sees the potential for Catgut in barbed sutures because of their quick degradation rate.

“These are useful external wound closures,” she says. “Because our body contains so much collagen and Catgut is made up of 90% collagen, it’s a more suitable polymer that can be used in human tissue.”

Hands-on experience informs research
In the meantime, Nambi Gowri has gained hands-on experience to inform her research by fabricating all of the barbed sutures used in Dr. Ruff’s micro facelift surgeries.

The surgery itself is made possible because of the shape and the material composition of the sutures: poly 4-hydroxybutyrate (P4HB). This polymer is already present naturally within our bodies, so sutures made from P4HB are naturally and safely absorbed by the body over time. That means patients don’t have to schedule an appointment after surgery for the sutures to be removed.
 
P4HB also provides the perfect combination of strength and elasticity to hold up the facial tissue until the wound has healed. The barbs, on the other hand, allow for the suture to be placed and stay secure within the skin without the need for large incisions.

“That skin tightens up right away,” Dr. Ruff says of the procedure, which draws patients from across the country. “So I don’t have to remove hair, and I don’t have to put a scar at the hairline.”

“These sutures are not available commercially anywhere in the world. So, to be able to mechanically barb different size sutures in a reliable and consistent manner for use in clinical practice, requires skill, experience and knowledge of quality control,” Professor King says of Nambi Gowri’s work.

This has given Karuna a hands-on understanding of the sutures she’s hoping to improve upon.

She says her fiber and polymer science knowledge has played a key role in helping her approach all sides of her research.

“All the analytical characterization techniques that are used for characterization of sutures – like identifying mechanical properties and measuring tensile strength – is actually from my knowledge of textiles,” she says. “I’m applying my polymer chemistry knowledge  to make sure that the laser doesn’t cause the sutures to degrade, melt or experience thermal damage.”

What’s next?
As she works to patent her designs, Nambi Gowri feels confident that her dissertation will set her up for success in the research and development (R&D) field after graduation.

In the meantime, she’s already finding out about the ways her research can have a broader impact.

“Dr. Dan Duffy, DVM, a surgeon at the NC State College of Veterinary Medicine is also interested in using barbed sutures to repair torn and failed tendons on his animals, but he finds the cost of buying commercial barbed sutures prohibitively expensive. So we need to collaborate,” King says. “Karuna to the rescue!”

Source:

North Carolina State University, Sarah Stone

New conductive, cotton-based fiber developed for smart textiles Photo: Dean Hare, WSU Photo Services
29.12.2023

New conductive, cotton-based fiber developed for smart textiles

A single strand of fiber developed at Washington State University has the flexibility of cotton and the electric conductivity of a polymer, called polyaniline.

The newly developed material showed good potential for wearable e-textiles. The WSU researchers tested the fibers with a system that powered an LED light and another that sensed ammonia gas, detailing their findings in the journal Carbohydrate Polymers.

“We have one fiber in two sections: one section is the conventional cotton: flexible and strong enough for everyday use, and the other side is the conductive material,” said Hang Liu, WSU textile researcher and the study’s corresponding author. “The cotton can support the conductive material which can provide the needed function.”

A single strand of fiber developed at Washington State University has the flexibility of cotton and the electric conductivity of a polymer, called polyaniline.

The newly developed material showed good potential for wearable e-textiles. The WSU researchers tested the fibers with a system that powered an LED light and another that sensed ammonia gas, detailing their findings in the journal Carbohydrate Polymers.

“We have one fiber in two sections: one section is the conventional cotton: flexible and strong enough for everyday use, and the other side is the conductive material,” said Hang Liu, WSU textile researcher and the study’s corresponding author. “The cotton can support the conductive material which can provide the needed function.”

While more development is needed, the idea is to integrate fibers like these into apparel as sensor patches with flexible circuits. These patches could be part of uniforms for firefighters, soldiers or workers who handle chemicals to detect for hazardous exposures. Other applications include health monitoring or exercise shirts that can do more than current fitness monitors.

“We have some smart wearables, like smart watches, that can track your movement and human vital signs, but we hope that in the future your everyday clothing can do these functions as well,” said Liu. “Fashion is not just color and style, as a lot of people think about it: fashion is science.”

In this study, the WSU team worked to overcome the challenges of mixing the conductive polymer with cotton cellulose. Polymers are substances with very large molecules that have repeating patterns. In this case, the researchers used polyaniline, also known as PANI, a synthetic polymer with conductive properties already used in applications such as printed circuit board manufacturing.

While intrinsically conductive, polyaniline is brittle and by itself, cannot be made into a fiber for textiles. To solve this, the WSU researchers dissolved cotton cellulose from recycled t-shirts into a solution and the conductive polymer into another separate solution. These two solutions were then merged together side-by-side, and the material was extruded to make one fiber.

The result showed good interfacial bonding, meaning the molecules from the different materials would stay together through stretching and bending.

Achieving the right mixture at the interface of cotton cellulose and polyaniline was a delicate balance, Liu said.

“We wanted these two solutions to work so that when the cotton and the conductive polymer contact each other they mix to a certain degree to kind of glue together, but we didn’t want them to mix too much, otherwise the conductivity would be reduced,” she said.

Additional WSU authors on this study included first author Wangcheng Liu as well as Zihui Zhao, Dan Liang, Wei-Hong Zhong and Jinwen Zhang. This research received support from the National Science Foundation and the Walmart Foundation Project.

Source:

Sara Zaske, WSU News & Media Relations

Chemist Unlocks Plastic Alternatives Using Proteins and Clothing Scraps Photo: Challa Kumar, professor emeritus of chemistry, in his lab. (Contributed photo)
21.12.2023

Chemist Unlocks Plastic Alternatives Using Proteins and Clothing Scraps

Challa Kumar has developed methods to create novel plastic-like materials using proteins and fabric.

Every year, 400 million tons of plastic waste are generated worldwide. Between 19 and 23 million tons of that plastic waste makes its way into aquatic ecosystems, and the remaining goes into the ground. An additional 92 million tons of cloth waste is generated annually.

Challa Kumar, professor emeritus of chemistry, “fed up” with the tremendous amount of toxic waste people continually pump into the environment, felt compelled to do something. As a chemist, doing something meant using his expertise to develop new, sustainable materials.

“Everyone should think about replacing fossil fuel-based materials with natural materials anywhere they can to help our civilization to survive,” Kumar says. “The house is on fire, we can’t wait. If the house is on fire and you start digging a well – that is not going to work. It’s time to start pouring water on the house.”

Challa Kumar has developed methods to create novel plastic-like materials using proteins and fabric.

Every year, 400 million tons of plastic waste are generated worldwide. Between 19 and 23 million tons of that plastic waste makes its way into aquatic ecosystems, and the remaining goes into the ground. An additional 92 million tons of cloth waste is generated annually.

Challa Kumar, professor emeritus of chemistry, “fed up” with the tremendous amount of toxic waste people continually pump into the environment, felt compelled to do something. As a chemist, doing something meant using his expertise to develop new, sustainable materials.

“Everyone should think about replacing fossil fuel-based materials with natural materials anywhere they can to help our civilization to survive,” Kumar says. “The house is on fire, we can’t wait. If the house is on fire and you start digging a well – that is not going to work. It’s time to start pouring water on the house.”

Kumar has developed two technologies that use proteins and cloth, respectively, to create new materials. UConn’s Technology Commercialization Services (TCS) has filed provisional patents for both technologies.

Inspired by nature’s ability to construct a diverse array of functional materials, Kumar and his team developed a method to produce continuously tunable non-toxic materials.

“Chemistry is the only thing standing in our way,” Kumar says. “If we understand protein chemistry, we can make protein materials as strong as a diamond or as soft as a feather.”

The first innovation is a process to transform naturally occurring proteins into plastic-like materials. Kumar’s student, Ankarao Kalluri ’23 Ph.D., worked on this project.

Proteins have “reactor groups” on their surfaces which can react with substances with which they come into contact. Using his knowledge of how these groups work, Kumar and his team used a chemical link to bind protein molecules together.

This process creates a dimer – a molecule composed to two proteins. From there, the dimer is joined with another dimer to create tetramer, and so on until it becomes a large 3D molecule. This 3D aspect of the technology is unique, since most synthetic polymers are linear chains.

This novel 3D structure allows the new polymer to behave like a plastic. Just like the proteins of which it is made, the material can stretch, change shape, and fold. Thus, the material can be tailored via chemistry for a variety of specific applications.

Unlike synthetic polymers, because Kumar’s material is made of proteins and a bio-linking chemical, it can biodegrade, just like plant and animal proteins do naturally.

“Nature degrades proteins by ripping apart the amide bonds that are in them,” Kumar says. “It has enzymes to handle that sort of chemistry. We have the same amide linkages in our materials. So, the same enzymes that work in biology should also work on this material and biodegrade it naturally.”

In the lab, the team found that the material degrades within a few days in acidic solution. Now, they are investigating what happens if they bury this material in the ground, which is the fate of many post-consumer plastics.

They have demonstrated that the protein-based material can form a variety of plastic-like products, including coffee cup lids and thin transparent films. It could also be used to make fire-resistant roof tiles, or higher-end materials like, car doors, rocket cone tips, or heart valves.

The next steps for this technology are to continue testing their mechanical properties, like strength or flexibility, as well as toxicity.

“I think we need to have social consciousness that we cannot put out materials into the environment that are toxic,” Kumar says. “We just cannot. We have to stop doing that. And we cannot use materials derived from fossil fuels either.”

Kumar’s second technology uses a similar principle, but instead of just proteins, uses proteins reinforced with natural fibers, specifically cotton.

“We are creating a lot of textile waste each year due to the fast-changing fashion industry” Kumar says. “So why not use that waste to create useful materials – convert waste to wealth.”

Just like the plastic-like protein materials (called “Proteios,” derived from original Greek words), Kumar expects composite materials made from proteins and natural fibers will biodegrade without producing toxic waste.

In the lab, Kumar’s former student, doctoral candidate Adekeye Damilola, created many objects with protein-fabric composites, which include small shoes, desks, flowers, and chairs. This material contains textile fibers which serve as the linking agent with the proteins, rather than the cross-linking chemical Kumar uses for the protein-based plastics.

The crosslinking provides the novel material with the strength to withstand the weight that would be put on something like a chair or a table. The natural affinity between fibers and proteins is why it’s so hard to get food stains out of clothing. This same attraction makes strong protein-fabric materials.

While Kumar’s team has only worked with cotton so far, they expect other fiber materials, like hemp fibers or jute, would behave similarly due to their inherent but common chemical properties with cotton.

“The protein naturally adheres to the surface of the protein,” Kumar says. “We used that understanding to say ‘Hey, if it binds so tightly to cotton, why don’t we make a material out of it.’ And it works, it works amazingly.”

With the support of TCS, Professor Kumar is currently seeking industry partners to bring these technologies to market. For more information contact Michael Invernale at michael.invernale@uconn.edu.

Source:

Anna Zarra Aldrich '20 (CLAS), Office of the Vice President for Research

Conceptualisation of a running shoe made out of a metamaterial. AI generated with DALL-E   (Visualisation: ETH Zurich) Conceptualisation of a running shoe made out of a metamaterial. AI generated with DALL-E (Visualisation: ETH Zurich)
18.12.2023

AI for safer bike helmets and better shoe soles

Researchers have trained an artificial intelligence to design the structure of so-called metamaterials with desired mechanical properties for a wide range of applications.

Researchers have trained an artificial intelligence to design the structure of so-called metamaterials with desired mechanical properties for a wide range of applications.

  • ETH researchers have used artificial intelligence to design metamaterials that show unusual or extraordinary responses to complex loads.
  • Their new AI tool deciphers the essential features of a metamaterial’s microstructure and accurately predicts its deformation behaviour.
  • The tool not only finds optimal microstructures but also bypasses time-consuming engineering simulations.

Bike helmets that absorb the energy of an impact, running shoes that give you an extra boost with every step, or implants that behave just like natural bone. Metamaterials make such applications possible. Their inner structure is the result of a careful design process, following which 3D printers produce structures with optimised properties. Researchers led by Dennis Kochmann, Professor of Mechanics and Materials in the Department of Mechanical and Process Engineering at ETH Zurich, have developed novel AI tools that bypass the time-consuming and intuition-based design process of metamaterials. Instead, they predict metamaterials with extraordinary properties in a rapid and automated fashion. A novelty, their framework applies to large (so-called non-linear) loads, e.g. when a helmet absorbs major forces during an impact.

Kochmann’s team has been among the pioneers in designing small-scale cellular structures (similar to beam networks in timber-frame houses) to create metamaterials with specific or extreme properties. “For example, we design metamaterials that behave like fluids: hard to compress but easy to deform. Or metamaterials that shrink in all directions when compressed in a particular one,” explains Kochmann.

Efficient, optimal material design
The design possibilities seem endless. However, the full potential of metamaterials is far from realised, since the design process is based on experience, involving trial and error. Furthermore, small changes in the structure can give rise to huge changes in properties.

In their recent breakthrough, the researchers succeeded in using AI to systematically explore the abundant design and mechanical properties of two types of metamaterials. Their computational tools can predict optimal structures for desired deformation responses at the push of a button. Key is the use of large datasets of the deformation behaviour of real structures to train an AI model that not only reproduces data but also generates and optimises new structures. By leveraging a method known as “variational autoencoders”, the AI learns the essential features of a structure from the large set of design parameters and how they result in specific properties. It then uses this knowledge to generate a metamaterial blueprint whenever the researchers specify its desired properties and requirements.

Assembling building blocks
Li Zheng, a doctoral student in Kochmann’s group, trained an AI model using a dataset of one million structures and their simulated response. “Imagine a huge box of Lego bricks – you can arrange them in countless ways and over time learn design principles. The AI does this extremely efficiently and learns essential design features and how to assemble the building blocks of metamaterials to give them a particular softness or hardness”, says Zheng. Unlike prior approaches using a small catalogue of building blocks as the basis for design, the new method gives the AI freedom to add, remove, or move building blocks around almost arbitrarily.  Together with Sid Kumar, an assistant professor at TU Delft and a former member of Kochmann’s team, they showed in a recently published paper that the AI model can even go beyond what it has been trained to do and predict structures that are far better than anything ever generated before.

Learning from the movies
Jan-Hendrik Bastek, also doctoral student in Kochmann’s group, used a different approach to achieve something similar. He used a method originally introduced for AI-based video generation, which has become commonplace: if you type in ‘an elephant flying over Zurich’, the AI generates a realistic video of an elephant circling the Fraumünster Church. Bastek trained his AI system using 50,000 video sequences of deforming 3D-printable structures. “I can insert the trajectory of how I want the structures to deform, and the AI produces a video of the optimal structure and the complete deformation response,” explains Bastek. Most previous approaches have focused on only predicting a single image of the optimal structure. However, giving the AI videos of the entire deformation process is crucial to retain accuracy in such complex scenarios. Based on the video sequences, the AI can create blueprints for new materials, taking into account highly complex scenarios.

Big benefits for bike helmets and shoe soles
The researchers have made available their AI tools to the metamaterials community. This will hopefully lead to the design of many new and unusual materials. The tools are opening new avenues for the development of protective equipment such as bicycle helmets and for further applications of metamaterials from medical engineering to soft robotics. Even shoe soles can be designed to absorb shocks better when running or to provide a forward boost when stepping down. Will AI completely replace the manual engineering design of materials? “No,” laughs Kochmann. “Used well, AI can be a highly efficient and diligent assistant, but it must be given the right instructions and the right training – and that requires scientific principles and engineering knowhow.”

Source:

ETH Zürich

Bild von Tumisu auf Pixabay
06.12.2023

Antimicrobial coating: Bacteria, stay out!

Hospital germs and pathogens are not always transmitted directly from person to person. They can also spread via germ-contaminated surfaces and objects. Empa researchers, together with the chemical company BASF, Spiez Laboratory and the Technical University of Berlin, have now developed coated textiles that inhibit or even kill pathogens. They could be used as antimicrobial curtains in hospitals in the future.

Hospital germs and pathogens are not always transmitted directly from person to person. They can also spread via germ-contaminated surfaces and objects. Empa researchers, together with the chemical company BASF, Spiez Laboratory and the Technical University of Berlin, have now developed coated textiles that inhibit or even kill pathogens. They could be used as antimicrobial curtains in hospitals in the future.

Countless times a day, patients, visitors and medical staff in hospitals touch surfaces of all kinds. Door handles, railings or elevator buttons can serve as transport vehicles for pathogens such as hospital germs or viruses. Smooth surfaces are comparatively easy to clean after contamination. With porous structures such as textiles, however, this is not that simple. Empa researchers have solved this problem together with experts from BASF, Spiez Laboratory and the Technical University of Berlin: A coating process can now be used to treat fabrics in such a way that bacterial and viral pathogens are killed or inhibited in their growth. In hospitals, the coated textiles could be used in future as antimicrobial curtains between patient beds, for example.

Active for months
"We were looking for a process that reliably prevents germs from contaminating textiles that come into contact with a large number of people during use," explains Peter Wick from Empa's Particles-Biology Interactions laboratory in St. Gallen. In this way, chains of infection could be interrupted in which multi-resistant bacteria or viral pathogens, for example, settle on hospital curtains and can then be spread by people.

The researchers ultimately developed a coating process in which a benzalkonium chloride-containing disinfectant was evenly applied to hospital curtains. After optimizing parameters such as concentration, exposure time, processing pressure and drying, the coating adhered stably to the textile surface. But did the coated textiles also exhibit a germicidal effect? This was to be shown by analyzing the antimicrobial activity of the first fabric samples.

"The results of the laboratory tests were very encouraging," says Wick. When the bacterial cultures of some typical problem germs were incubated with the fabric samples, the coated textiles inhibited the growth of staphylococci and pseudomonas bacteria, for example. "The hospital germs were significantly reduced or even killed after just ten minutes of exposure," says the Empa researcher. Moreover, the coating was also active against viral pathogens: Over 99 percent of the viruses were killed by the coated fabric samples.

Another advantage: The coatings remained effective even after several months of storage. This allows production in stock. With the new process, other textiles, filters or cleaning utensils could also be quickly and safely treated with antimicrobials in the future, for example in the event of an epidemic, emphasizes Empa researcher Wick.

Source:

EMPA

JUMBO-Textil production © JUMBO-Textil GmbH & Co. KG
28.11.2023

JUMBO-Textil: "For us, leadership means team development."

With its high-quality technical narrow textiles, JUMBO-Textil stands for high-tech - whether woven, braided or knitted. As an elastic specialist and solution partner, the company develops and produces individual innovations for customers worldwide. The 70-strong team must be as diverse and flexible as the products it designs. Textination spoke to industrial engineer Carl Mrusek about the current challenges facing family businesses. Carl Mrusek, who has been Chief Sales Officer (CSO) at Textation Group GmbH & Co. KG, to which JUMBO-Textil belongs, for almost a year now, is in charge of strategic corporate development as well as other areas of responsibility.

 

With its high-quality technical narrow textiles, JUMBO-Textil stands for high-tech - whether woven, braided or knitted. As an elastic specialist and solution partner, the company develops and produces individual innovations for customers worldwide. The 70-strong team must be as diverse and flexible as the products it designs. Textination spoke to industrial engineer Carl Mrusek about the current challenges facing family businesses. Carl Mrusek, who has been Chief Sales Officer (CSO) at Textation Group GmbH & Co. KG, to which JUMBO-Textil belongs, for almost a year now, is in charge of strategic corporate development as well as other areas of responsibility.

 

"In a family business, tradition is the foundation, innovation is the way forward," they say. The image of family-run companies has changed significantly in recent years - old-fashioned values and outdated business concepts have given way to a strong corporate culture, a strong sense of regional responsibility and sustainable planning. How does JUMBO-Textil combine its corporate values and traditions with a contemporary management style?

Carl Mrusek: As a family business, there is a close bond between the employees and the company and vice versa; the continuity of human relationships is important and valuable. JUMBO-Textil also has a tradition of one thing in particular: contemporary corporate management, both technically and professionally, as well as in terms of management style and values. Especially in a family business, which is often managed by the same person for decades, it is crucial to question corporate values and management style and to promote change. A company that has been operating successfully internationally for almost 115 years must be adaptable. For us, reacting quickly to changes, even anticipating them and moving forward accordingly, is at the heart of smart business practices. The specialization in elastics in the 1920s is an example of the foresighted power of change, as is the strategically important turn to technical textiles in the 1970s. A recent example is the merger with vombaur under the umbrella of the Textation Group.

The most important thing in any company is its employees. We would not be able to attract and retain them with outdated traditions and working methods. For us, the focus is not on the company management, but on joint success, and in a complex world, this is usually the result of successful cooperation and not an announcement from the boss. Leadership clearly means setting and pursuing strategic goals, but today it also means team development. Finding the best people, bringing them together and motivating them to achieve the goal.

 

Team spirit and vision development: How do you achieve this at JUMBO-Textil?

Carl Mrusek: As a team! JUMBO-Textil has systematically expanded its management team. In addition to the Managing Director, our CEO Andreas Kielholz, the Chief Operational Officer Patrick Kielholz, the Chief Financial Officer Ralph Cammerath, the Chief Technology Officer Dr. Sven Schöfer and myself as Chief Sales Officer work here. This shows that we are convinced of the idea of cooperation: We also work together on corporate development and strategic issues. The same applies to the individual teams - in organizational specialist teams or in interdisciplinary project teams. The tasks for which we are responsible may be different, but each is equally important.

 

Is that why you start the introduction of contact persons on your website with the Junior Sales Manager? And the C-level representatives are at the end?

Carl Mrusek: Yes, all JUMBO-Textil heads are the head of the company for us. All JUMBO-Textil faces represent the company. This is also reflected in the order of the contact persons on the website. Visitors should be able to quickly find the person who can help them and not find out who runs the company. That's what the legal notice is for. (laughs)

 

What is JUMBO-Textil's mission statement and vision for the future, and what needs to change in order to achieve this vision?

Carl Mrusek: We are currently working on the strategic direction of the Textation Group, which JUMBO-Textil GmbH & Co. KG and vombaur GmbH & Co. KG are part of. In this context, we have developed the Group's corporate vision and mission and updated our mission statement. This serves as a foundation for strategy development and is only sustainable if employees are involved in this process through surveys and workshops. I don't want to give too much away yet, but this much is already clear: strong teams, the right people in the right place, taking responsibility at all levels, sustainability as the basis for innovation - these will be the four cornerstones. You can already see from this: To achieve our vision, we cannot flip a switch. We must always remain open to change, always new - from product development to personnel recruitment. But as I said, we have a tradition of doing this.

 

JUMBO-Textil is not an industry specialist, but combines expertise for demanding high-tech narrow textiles. Who is in charge of challenging customer projects - do you decide in a team or rather top-down, where is the responsibility for an order placed?

Carl Mrusek: As a team, we decide which projects to implement and how to prioritize them. The corporate strategy determines the "direction of travel". In addition to the sales side, the development side of new projects also plays a decisive role. I therefore coordinate intensively with Dr. Sven Schöfer (CTO) and his team, as the focus here is on the technical development and implementation of our products. In the end, project processing is always a team effort between Sales and Development in close cooperation with Production..

 

Between above-standard pay, a 4-day week and the much-vaunted work-life balance in the current situation on the job market, companies are more likely to be in the position of applicants than vice versa. What are you doing to remain attractive as an employer for new colleagues? And how do you keep the enthusiasm of your skilled employees at a consistently high level?

Carl Mrusek: An important approach for us is education. Training young people and proving to them during their apprenticeship: JUMBO-Textil is your place to be. We therefore already start recruiting skilled workers through our school visits and school internships. As a state-of-the-art company, we offer an attractive salary level and a pleasant and healthy working environment.

Applicants today also often want to organize their working hours and work arrangements individually and flexibly, for a variety of reasons. With modern working models and thanks to our ongoing progress in digitalization, we support them wherever possible. People also want to work for a company that they can identify with. Environmental and climate protection are just as important to our employees and applicants as social standards in our supply chain. The fact that we have set ourselves ambitious goals with our sustainability strategy and are consistently pursuing them with firmly scheduled steps - our climate-neutral energy generation is a concrete example that has already been implemented. Furthermore, we vigorously encourage our business partners to respect human and employee rights and are committed to the Code of Conduct of the German textile and fashion industry. All of this helps us to recruit staff.

 

What larger, more capital-intensive companies can partially make up for with financial resources, SMEs have to manage through agility and adaptability - especially in situations of crisis. To what extent are these requirements also reflected in your organizational structure and the requirements profile for employees?

Carl Mrusek: Exactly, that is the advantage that family businesses have over large corporations: We can make decisions quickly and react on a daily basis if necessary. Hierarchies are flat and coordination processes are short. An exciting suggestion doesn't have to be prepared by agencies and coordinated across several levels before it is approved by the management and can be implemented. The go-ahead can also come immediately over lunch: "Great idea, we'll do it." In a corporate group, this fails because only very few employees have the opportunity to have lunch with the management. - And we only talk about business in exceptional cases. Most of the time, the break is about family, the weather, sports and leisure plans - lunch topics, in other words. - We need responsible team players who are willing to make a change. People who work with others on an equal footing, who are committed to the company and its goals with drive and expertise and who are keen to try new things.

 

It now takes much more than a fruit basket and a gym to motivate current and potential employees. Working in a meaningful way and participating in a climate-friendly transformation is particularly important to many people. What does JUMBO-Textil do specifically to not just quote SDGs in a statement, but to live them in everyday company life?

Carl Mrusek: We have set ourselves a specific climate target: By 2035, our administrative and production operations at our headquarters will be climate-neutral. Realistic steps have been defined to achieve this. We have already achieved an important interim goal: at our headquarters in Sprockhövel, we only use green electricity from the sun, wind and water. We offset the unavoidable emissions for our heat generation with CO2 compensation services. We are also developing more and more products from recyclable and recycled materials. Our vehicle fleet is currently being converted to purely electric or hybrid models.

 

Diversification and internationalization are part of every corporate strategy these days. But what do these terms mean for the management style of a medium-sized company in Sprockhövel? Do you consciously build interdisciplinary international teams?

Carl Mrusek: We live in a hyper-diverse society. This is also reflected in our company. Our teams consist of people with different international backgrounds, without us having to actively control this. The age structure is now also very mixed. We see the different perspectives as an asset, an opportunity and a success factor. We - and that ultimately means our customers and their projects - benefit from the variety of perspectives that flow into our solutions. As with many companies in the technical textiles sector, the proportion of women in some teams is still somewhat unbalanced. However, it is fortunately increasing steadily.

 

Generational change and succession planning are core issues for family-run companies. How important is it for JUMBO-Textil to professionalize its management team and to what extent is the company open to external specialists and managers?

Carl Mrusek: A company that closes its doors to external specialists and managers is also closing a door to success. That would be foolish. At JUMBO-Textil, we try to combine and balance the close ties, personal continuity and flexibility of a family-run company, the passion and innovative spirit of a start-up and the solidity and financial strength of a group. With Patrick Kielholz as COO, the next generation of the family is represented at management level, as is the external view and the diversity of perspectives provided by the other new members at C-level. The Textation Group, which also includes Patrick Kielholz's brother Kevin Kielholz, supports the company and enables it to think and act bigger than medium-sized family businesses often do. JUMBO-Textil is an elastic specialist. And what distinguishes our product also distinguishes us as an organization. We span the advantages of a family business as well as those of a start-up and a group. If I may use the image of elasticity here and not stretch it too far. (laughs)