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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

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

06.11.2023

Shape-shifting fiber can produce morphing fabrics

The low-cost FibeRobo, which is compatible with existing textile manufacturing techniques, could be used in adaptive performance wear or compression garments.

Researchers from MIT and Northeastern University developed a liquid crystal elastomer fiber that can change its shape in response to thermal stimuli. The fiber, which is fully compatible with existing textile manufacturing machinery, could be used to make morphing textiles, like a jacket that becomes more insulating to keep the wearer warm when temperatures drop.

The low-cost FibeRobo, which is compatible with existing textile manufacturing techniques, could be used in adaptive performance wear or compression garments.

Researchers from MIT and Northeastern University developed a liquid crystal elastomer fiber that can change its shape in response to thermal stimuli. The fiber, which is fully compatible with existing textile manufacturing machinery, could be used to make morphing textiles, like a jacket that becomes more insulating to keep the wearer warm when temperatures drop.

Instead of needing a coat for each season, imagine having a jacket that would dynamically change shape so it becomes more insulating to keep you warm as the temperature drops.
A programmable, actuating fiber developed by an interdisciplinary team of MIT researchers could someday make this vision a reality. Known as FibeRobo, the fiber contracts in response to an increase in temperature, then self-reverses when the temperature decreases, without any embedded sensors or other hard components.

The low-cost fiber is fully compatible with textile manufacturing techniques, including weaving looms, embroidery, and industrial knitting machines, and can be produced continuously by the kilometer. This could enable designers to easily incorporate actuation and sensing capabilities into a wide range of fabrics for myriad applications.

The fibers can also be combined with conductive thread, which acts as a heating element when electric current runs through it. In this way, the fibers actuate using electricity, which offers a user digital control over a textile’s form. For instance, a fabric could change shape based on any piece of digital information, such as readings from a heart rate sensor.

“We use textiles for everything. We make planes with fiber-reinforced composites, we cover the International Space Station with a radiation-shielding fabric, we use them for personal expression and performance wear. So much of our environment is adaptive and responsive, but the one thing that needs to be the most adaptive and responsive — textiles — is completely inert,” says Jack Forman, a graduate student in the Tangible Media Group of the MIT Media Lab, with a secondary affiliation at the Center for Bits and Atoms, and lead author of a paper on the actuating fiber.

He is joined on the paper by 11 other researchers at MIT and Northeastern University, including his advisors, Professor Neil Gershenfeld, who leads the Center for Bits and Atoms, and Hiroshi Ishii, the Jerome B. Wiesner Professor of Media Arts and Sciences and director of the Tangible Media Group. The research will be presented at the ACM Symposium on User Interface Software and Technology.

Morphing materials
The MIT researchers wanted a fiber that could actuate silently and change its shape dramatically, while being compatible with common textile manufacturing procedures. To achieve this, they used a material known as liquid crystal elastomer (LCE).

A liquid crystal is a series of molecules that can flow like liquid, but when they’re allowed to settle, they stack into a periodic crystal arrangement. The researchers incorporate these crystal structures into an elastomer network, which is stretchy like a rubber band.

As the LCE material heats up, the crystal molecules fall out of alignment and pull the elastomer network together, causing the fiber to contract. When the heat is removed, the molecules return to their original alignment, and the material to its original length, Forman explains.

By carefully mixing chemicals to synthesize the LCE, the researchers can control the final properties of the fiber, such as its thickness or the temperature at which it actuates.

They perfected a preparation technique that creates LCE fiber which can actuate at skin-safe temperatures, making it suitable for wearable fabrics.

“There are a lot of knobs we can turn. It was a lot of work to come up with this process from scratch, but ultimately it gives us a lot of freedom for the resulting fiber,” he adds.
However, the researchers discovered that making fiber from LCE resin is a finicky process. Existing techniques often result in a fused mass that is impossible to unspool.

Researchers are also exploring other ways to make functional fibers, such as by incorporating hundreds of microscale digital chips into a polymer, utilizing an activated fluidic system, or including piezoelectric material that can convert sound vibrations into electrical signals.

Fiber fabrication
Forman built a machine using 3D-printed and laser-cut parts and basic electronics to overcome the fabrication challenges. He initially built the machine as part of the graduate-level course MAS.865 (Rapid-Prototyping of Rapid-Prototyping Machines: How to Make Something that Makes [almost] Anything).

To begin, the thick and viscous LCE resin is heated, and then slowly squeezed through a nozzle like that of a glue gun. As the resin comes out, it is cured carefully using UV lights that shine on both sides of the slowly extruding fiber.

If the light is too dim, the material will separate and drip out of the machine, but if it is too bright, clumps can form, which yields bumpy fibers.

Then the fiber is dipped in oil to give it a slippery coating and cured again, this time with UV lights turned up to full blast, creating a strong and smooth fiber. Finally, it is collected into a top spool and dipped in powder so it will slide easily into machines for textile manufacturing.
From chemical synthesis to finished spool, the process takes about a day and produces approximately a kilometer of ready-to-use fiber.

“At the end of the day, you don’t want a diva fiber. You want a fiber that, when you are working with it, falls into the ensemble of materials — one that you can work with just like any other fiber material, but then it has a lot of exciting new capabilities,” Forman says.

Creating such a fiber took a great deal of trial and error, as well as the collaboration of researchers with expertise in many disciplines, from chemistry to mechanical engineering to electronics to design.

The resulting fiber, called FibeRobo, can contract up to 40 percent without bending, actuate at skin-safe temperatures (the skin-safe version of the fiber contracts up to about 25 percent), and be produced with a low-cost setup for 20 cents per meter, which is about 60 times cheaper than commercially available shape-changing fibers.

The fiber can be incorporated into industrial sewing and knitting machines, as well as nonindustrial processes like hand looms or manual crocheting, without the need for any process modifications.
The MIT researchers used FibeRobo to demonstrate several applications, including an adaptive sports bra made by embroidery that tightens when the user begins exercising.

They also used an industrial knitting machine to create a compression jacket for Forman’s dog, whose name is Professor. The jacket would actuate and “hug” the dog based on a Bluetooth signal from Forman’s smartphone. Compression jackets are commonly used to alleviate the separation anxiety a dog can feel while its owner is away.

In the future, the researchers want to adjust the fiber’s chemical components so it can be recyclable or biodegradable. They also want to streamline the polymer synthesis process so users without wet lab expertise could make it on their own.

Forman is excited to see the FibeRobo applications other research groups identify as they build on these early results. In the long run, he hopes FibeRobo can become something a maker could buy in a craft store, just like a ball of yarn, and use to easily produce morphing fabrics.

“LCE fibers come to life when integrated into functional textiles. It is particularly fascinating to observe how the authors have explored creative textile designs using a variety of weaving and knitting patterns,” says Lining Yao, the Cooper-Siegel Associate Professor of Human Computer Interaction at Carnegie Mellon University, who was not involved with this work.

This research was supported, in part, by the William Asbjornsen Albert Memorial Fellowship, the Dr. Martin Luther King Jr. Visiting Professor Program, Toppan Printing Co., Honda Research, Chinese Scholarship Council, and Shima Seiki. The team included Ozgun Kilic Afsar, Sarah Nicita, Rosalie (Hsin-Ju) Lin, Liu Yang, Akshay Kothakonda, Zachary Gordon, and Cedric Honnet at MIT; and Megan Hofmann and Kristen Dorsey at Northeastern University.

Source:

MIT and Northeastern University

Photo: zephylwer0, Pixabay
29.08.2023

Taming a fire: A new way with nanoscale material

High-temperature flames are used to create a wide variety of materials – but once you start a fire, it can be difficult to control how the flame interacts with the material you are trying to process. Researchers have now developed a technique that utilizes a molecule-thin protective layer to control how the flame’s heat interacts with the material – taming the fire and allowing users to finely tune the characteristics of the processed material.

“Fire is a valuable engineering tool – after all, a blast furnace is only an intense fire,” says Martin Thuo, corresponding author of a paper on the work and a professor of materials science and engineering at North Carolina State University. “However, once you start a fire, you often have little control over how it behaves.

High-temperature flames are used to create a wide variety of materials – but once you start a fire, it can be difficult to control how the flame interacts with the material you are trying to process. Researchers have now developed a technique that utilizes a molecule-thin protective layer to control how the flame’s heat interacts with the material – taming the fire and allowing users to finely tune the characteristics of the processed material.

“Fire is a valuable engineering tool – after all, a blast furnace is only an intense fire,” says Martin Thuo, corresponding author of a paper on the work and a professor of materials science and engineering at North Carolina State University. “However, once you start a fire, you often have little control over how it behaves.

“Our technique, which we call inverse thermal degradation (ITD), employs a nanoscale thin film over a targeted material. The thin film changes in response to the heat of the fire, and regulates the amount of oxygen that can access the material. That means we can control the rate at which the material heats up – which, in turn, influences the chemical reactions taking place within the material. Basically, we can fine-tune how and where the fire changes the material.”

Here’s how ITD works. You start out with your target material, such as a cellulose fiber. That fiber is then coated with a nanometer thick layer of molecules. The coated fibers are then exposed to an intense flame. The outer surface of the molecules combusts easily, raising the temperature in the immediate vicinity. But the inner surface of the molecular coating chemically changes, creating an even thinner layer of glass around the cellulose fibers. This glass limits the amount of oxygen that can access the fibers, preventing the cellulose from bursting into flames. Instead, the fibers smolder – burning slowly, from the inside out.

“Without the ITD’s protective layer, applying flame to cellulose fibers would just result in ash,” Thuo says. “With the ITD’s protective layer, you end up with carbon tubes.

“Without the ITD’s protective layer, applying flame to cellulose fibers would just result in ash,” Thuo says. “With the ITD’s protective layer, you end up with carbon tubes.

“We can engineer the protective layer in order to tune the amount of oxygen that reaches the target material. And we can engineer the target material in order to produce desirable characteristics.”

The researchers conducted proof-of-concept demonstrations with cellulose fibers to produce microscale carbon tubes.

The researchers could control the thickness of the carbon tube walls by controlling the size of the cellulose fibers they started with; by introducing various salts to the fibers (which further controls the rate of burning); and by varying the amount of oxygen that passes through the protective layer.

“We have several applications in mind already, which we will be addressing in future studies,” Thuo says. “We’re also open to working with the private sector to explore various practical uses, such as developing engineered carbon tubes for oil-water separation – which would be useful for both industrial applications and environmental remediation.”

The paper, “Spatially Directed Pyrolysis via Thermally Morphing Surface Adducts,” is published in the journal Angewandte Chemie. Co-authors are Dhanush Jamadgni and Alana Pauls, Ph.D. students at NC State; Julia Chang and Andrew Martin, postdoctoral researchers at NC State; Chuanshen Du, Paul Gregory, Rick Dorn and Aaron Rossini of Iowa State University; and E. Johan Foster at the University of British Columbia.

Source:

North Carolina State University, Matt Shipman

Ultra-thin smart textiles are being refined for their use in obstetric monitoring and will enable analysis of vital data via app for pregnancies. Photo: Pixabay, Marjon Besteman
24.07.2023

Intelligent Patch for Remote Monitoring of Pregnancy

During pregnancy, regular medical check-ups provide information about the health and development of the pregnant person and the child. However, these examinations only provide snapshots of their state, which can be dangerous, especially in high-risk cases. To enable convenient and continuous monitoring during this sensitive phase, an international research consortium is planning to further develop the technology of smart textiles. A patch equipped with highly sensitive electronics is meant to collect and evaluate vital data. In addition, the sensors will be integrated into baby clothing in order to improve the future of medical monitoring for newborns with the highest level of data security.

During pregnancy, regular medical check-ups provide information about the health and development of the pregnant person and the child. However, these examinations only provide snapshots of their state, which can be dangerous, especially in high-risk cases. To enable convenient and continuous monitoring during this sensitive phase, an international research consortium is planning to further develop the technology of smart textiles. A patch equipped with highly sensitive electronics is meant to collect and evaluate vital data. In addition, the sensors will be integrated into baby clothing in order to improve the future of medical monitoring for newborns with the highest level of data security.

The beginning of a pregnancy is accompanied by a period of intensive health monitoring of the baby and the pregnant person. Conventional prenatal examinations with ultrasound devices, however, only capture snapshots of the respective condition and require frequent visits to doctors, especially in high-risk pregnancies. With the help of novel wearables and smart textiles, researchers in the EU-funded project Newlife aim to enable continuous obstetric monitoring in everyday life.

One goal of the consortium, consisting of 25 partners, is the development of a biocompatible, stretchable, and flexible patch to monitor the progress of the pregnancy and the embryo. Similar to a band-aid, the patch will be applied to the pregnant person’s skin, continuously recording vital data using miniaturized sensors (e.g., ultrasound) and transmitting it via Bluetooth.

For some time now, modern medical technology has been relying on smart textiles and intelligent wearables to offer patients convenient, continuous monitoring at home instead of stationary surveillance. At the Fraunhofer Institute for Reliability and Microelectronics IZM, a team led by Christine Kallmayer is bringing this technology to application-oriented implementation, benefitting from the Fraunhofer IZM’s years of experience with integrating technologies into flexible materials. For the integrated patch, the researchers are using thermoplastic polyurethane as base materials, in which electronics and sensors are embedded. This ensures that the wearing experience is similar to that of a regular band-aid instead of a rigid film.

To ensure that the obstetric monitoring is imperceptible and comfortable for both pregnant individuals and the unborn child, the project consortium plans to integrate innovative MEMS-based ultrasound sensors directly into the PU material. The miniaturized sensors are meant to record data through direct skin contact. Stretchable conductors made of TPU material tracks will then transmit the information to the electronic evaluation unit and finally to a wireless interface, allowing doctors and midwives to view all relevant data in an app. In addition to ultrasound, the researchers are planning to integrate additional sensors such as microphones, temperature sensors, and electrodes.

Even after birth, the new integration technology can be of great benefit to medical technology: With further demonstrators, the Newlife team plans to enable the monitoring of newborns. Sensors for continuous ECG, respiration monitoring, and infrared spectroscopy to observe brain activity will be integrated into the soft textile of a baby bodysuit and a cap. "Especially for premature infants and newborns with health risks, remote monitoring is a useful alternative to hospitalization and wired monitoring. For this purpose, we must guarantee an unprecedented level of comfort provided by the ultra-thin smart textiles: no electronics should be noticeable. Additionally, the entire module has to be extremely reliable, as the smart textiles should easily withstand washing cycles," explains Christine Kallmayer, project manager at Fraunhofer IZM.

For external monitoring of the baby's well-being, the project is also researching ways to use camera data and sensor technology in the baby's bed. Once the hardware basis of the patch, the textile electronics, and the sensor bed is built and tested, the project partners will take another step forward. Through cloud-based solutions, AI and machine learning will be used to simplify the implementation for medical staff and ensure the highest level of data security.

The Newlife project is coordinated by Philips Electronics Nederland B.V. and will run until the end of 2025. It is funded by the European Union under the Horizon Europe program as part of Key Digital Technologies Joint Undertaking under grant number 101095792 with a total of 18.7 million euros.

Source:

Fraunhofer Institute for Reliability and Microintegration IZM

Thread-like pumps can be woven into clothes (c) LMTS EPFL
27.06.2023

Thread-like pumps can be woven into clothes

Ecole Polytechnique Fédérale de Lausanne (EPFL) researchers have developed fiber-like pumps that allow high-pressure fluidic circuits to be woven into textiles without an external pump. Soft supportive exoskeletons, thermoregulatory clothing, and immersive haptics can therefore be powered from pumps sewn into the fabric of the devices themselves.

Many fluid-based wearable assistive technologies today require a large and noisy pump that is impractical – if not impossible – to integrate into clothing. This leads to a contradiction: wearable devices are routinely tethered to unearable pumps. Now, researchers at the Soft Transducers Laboratory (LMTS) in the School of Engineering have developed an elegantly simple solution to this dilemma.

Ecole Polytechnique Fédérale de Lausanne (EPFL) researchers have developed fiber-like pumps that allow high-pressure fluidic circuits to be woven into textiles without an external pump. Soft supportive exoskeletons, thermoregulatory clothing, and immersive haptics can therefore be powered from pumps sewn into the fabric of the devices themselves.

Many fluid-based wearable assistive technologies today require a large and noisy pump that is impractical – if not impossible – to integrate into clothing. This leads to a contradiction: wearable devices are routinely tethered to unearable pumps. Now, researchers at the Soft Transducers Laboratory (LMTS) in the School of Engineering have developed an elegantly simple solution to this dilemma.

“We present the world’s first pump in the form of a fiber; in essence, tubing that generates its own pressure and flow rate,” says LMTS head Herbert Shea. “Now, we can sew our fiber pumps directly into textiles and clothing, leaving conventional pumps behind.” The research has been published in the journal Science.

Lightweight, powerful…and washable
Shea’s lab has a history of forward-thinking fluidics. In 2019, they produced the world’s first stretchable pump.

“This work builds on our previous generation of soft pump,” says Michael Smith, an LMTS post-doctoral researcher and lead author of the study. “The fiber format allows us to make lighter, more powerful pumps that are inherently more compat-ible with wearable technology.”

The LMTS fiber pumps use a principle called charge injection electrohydrodynamics (EHD) to generate a fluid flow without any moving parts. Two helical electrodes embedded in the pump wall ionize and accelerate molecules of a special non-conductive liquid. The ion movement and electrode shape generate a net forward fluid flow, resulting in silent, vibration-free operation, and requiring just a palm-sized power supply and battery.

To achieve the pump’s unique structure, the researchers developed a novel fabrication technique that involves twisting copper wires and polyurethane threads together around a steel rod, and then fusing them with heat. After the rod is removed, the 2 mm fibers can be integrated into textiles using standard weaving and sewing techniques.

The pump’s simple design has a number of advantages. The materials required are cheap and readily available, and the manufacturing process can be easily scaled up. Because the amount of pressure generated by the pump is directly linked to its length, the tubes can be cut to match the application, optimizing performance while minimizing weight. The robust design can also be washed with conventional detergents.

From exoskeletons to virtual reality
The authors have already demonstrated how these fiber pumps can be used in new and exciting wearable technologies. For example, they can circulate hot and cold fluid through garments for those working in extreme temperature environments or in a therapeutic setting to help manage inflammation; and even for those looking to optimize athletic performance.

“These applications require long lengths of tubing anyway, and in our case, the tubing is the pump. This means we can make very simple and lightweight fluidic circuits that are convenient and comfortable to wear,” Smith says.

The study also describes artificial muscles made from fabric and embedded fiber pumps, which could be used to power soft exoskeletons to help patients move and walk.

The pump could even bring a new dimension to the world of virtual reality by simulating the sensation of temperature. In this case, users wear a glove with pumps filled with hot or cold liquid, allowing them to feel temperature changes in response to contact with a virtual object.

Pumped up for the future
The researchers are already looking to improve the performance of their device. “The pumps already perform well, and we’re confident that with more work, we can continue to make improvements in areas like efficiency and lifetime,” says Smith. Work has already started on scaling up the production of the fiber pumps, and the LMTS also has plans to embed them into more complex wearable devices.

“We believe that this innovation is a game-changer for wearable technology,” Shea says.

More information:
EPFL Fibers exoskeleton wearables
Source:

Celia Luterbacher, School of Engineering | STI

Separating microplastics Photo: H & M Foundation
22.05.2023

Soundwaves to separate microplastics from wastewater

The technology developed by The Hong Kong Research Institute of Textiles and Apparel (HKRITA) with the support of H&M Foundation, can separate microplastics from wastewater using soundwaves. Acousweep is a plug-and-play application. The technology can be easily transported and connected to any wastewater facility. If the technology is implemented at an industrial scale, it will have a significant impact on the fashion industry’s sustainable footprint.
 

The technology developed by The Hong Kong Research Institute of Textiles and Apparel (HKRITA) with the support of H&M Foundation, can separate microplastics from wastewater using soundwaves. Acousweep is a plug-and-play application. The technology can be easily transported and connected to any wastewater facility. If the technology is implemented at an industrial scale, it will have a significant impact on the fashion industry’s sustainable footprint.
 
Microplastic pollution is a globally established problem and a threat to ecosystems, animals, and people. Microplastics come from a variety of sources, including from larger plastic debris that degrades into smaller and smaller pieces, or microbeads in exfoliating health and beauty products, or cleansers such as toothpaste. According to the European Environment Agency the major source of oceanic microplastic pollution, about 16%-35% globally, comes from synthetic textiles. Professor Christine Loh, Chief Development Strategist at the Institute for the Environment, The Hong Kong University of Science and Technology, agrees that this technology has great potential.

Microplastics typically refers to tiny plastic pieces or particles smaller than 5mm in diameter according to the definition of United Nations Environment Programme (UNEP) and the European Union (EU). The new technology can separate microplastic fibre longer than 20 μm, which is 250 times smaller than the typical size. Unlike existing filtration processes, the system enables continuous water treatment and easy collection of microplastic fibres by virtue of its acoustic manipulation technique.

Acousweep utilises sweeping acoustic waves in a specially shaped chamber to physically trap and separate microplastic fibres from wastewater effectively. The whole process is merely a physical collection and separation. No chemical, solvent or biological additives are needed. The separated microplastics drip into a collection tank for further treatment, such as recycling. Acousweep, with a developing lab-scale treatment system of the capacity of 100L of water per hour, can be upscaled in industrial plants. The system can be installed in a container with a processing capacity up to 5-10T per hour. The containerised system can be easily transported and connected to the existing sewage outlets of the wastewater treatment system.
 
Process of Microplastic Fibre Separation:

  1. At one end of the chamber is a transducer that generates a sweeping acoustic wave at ultrasound frequencies. At the other end, there is a reflector, inside which sweeping acoustic waves are reflected and forms standing waves.
  2. When standing waves are applied to the particles in a fluid, an acoustic radiation force traps the particles.
  3. The standing waves then transfer the trapped particles to the reflector side; after that, particles concentrate at the apex of the reflector.
  4. At the apex is a needle valve which is controlled by a sensory system that monitors the concentration of microplastic fibres there. When the concentration is sufficiently high, the sensory system opens the needle valve to let the microplastic fibres drip into a collection tank.
  5. A high temperature can be applied to the collection tank to remove the water, leaving the fibres to agglomerate and form a large mass that can be easily dealt with in future treatment.

Green tech has just taken a leap forward in Hong Kong. Acousweep will help the garment and other industries to stop a highly damaging form of pollution. HKRITA used a new technique to remove the microplastics by using soundwave-based system, preventing them from getting into the sea and being ingested by sea life that can even be ingested by humans along the food chain. Acousweep has the capacity to revolutionize industry, says Professor Christine Loh, Chief Development Strategist at the Institute for the Environment, The Hong Kong University of Science and Technology.

 

Source:

The Hong Kong Research Institute of Textiles and Apparel (HKRITA); H & M Foundation

A cotton knit fabric dyed blue and washed 10 times to simulate worn garments is enzymatically degraded to a slurry of fine fibers and "blue glucose" syrup that are separated by filtration - both of these separated fractions have potential recycle value. A cotton knit fabric dyed blue and washed 10 times to simulate worn garments is enzymatically degraded to a slurry of fine fibers and "blue glucose" syrup that are separated by filtration - both of these separated fractions have potential recycle value. Credit: Sonja Salmon.
11.04.2023

Researchers Separate Cotton from Polyester in Blended Fabric

In a new study, North Carolina State University researchers found they could separate blended cotton and polyester fabric using enzymes – nature’s tools for speeding chemical reactions. Ultimately, they hope their findings will lead to a more efficient way to recycle the fabric’s component materials, thereby reducing textile waste. However, they also found the process need more steps if the blended fabric was dyed or treated with chemicals that increase wrinkle resistance.

In a new study, North Carolina State University researchers found they could separate blended cotton and polyester fabric using enzymes – nature’s tools for speeding chemical reactions. Ultimately, they hope their findings will lead to a more efficient way to recycle the fabric’s component materials, thereby reducing textile waste. However, they also found the process need more steps if the blended fabric was dyed or treated with chemicals that increase wrinkle resistance.

“We can separate all of the cotton out of a cotton-polyester blend, meaning now we have clean polyester that can be recycled,” said the study’s corresponding author Sonja Salmon, associate professor of textile engineering, chemistry and science at NC State. “In a landfill, the polyester is not going to degrade, and the cotton might take several months or more to break down. Using our method, we can separate the cotton from polyester in less than 48 hours.”
 
According to the U.S. Environmental Protection Agency, consumers throw approximately 11 million tons of textile waste into U.S. landfills each year. Researchers wanted to develop a method of separating the cotton from the polyester so each component material could be recycled.

In the study, researchers used a “cocktail” of enzymes in a mildly acidic solution to chop up cellulose in cotton. Cellulose is the material that gives structure to plants’ cell walls. The idea is to chop up the cellulose so it will “fall out” out of the blended woven structure, leaving some tiny cotton fiber fragments remaining, along with glucose. Glucose is the biodegradable byproduct of degraded cellulose. Then, their process involves washing away the glucose and filtering out the cotton fiber fragments, leaving clean polyester.
 
“This is a mild process – the treatment is slightly acidic, like using vinegar,” Salmon said. “We also ran it at 50 degrees Celsius, which is like the temperature of a hot washing machine.
“It’s quite promising that we can separate the polyester to a clean level,” Salmon added. “We still have some more work to do to characterize the polyester’s properties, but we think they will be very good because the conditions are so mild. We’re just adding enzymes that ignore the polyester.”

They compared degradation of 100% cotton fabric to degradation of cotton and polyester blends, and also tested fabric that was dyed with red and blue reactive dyes and treated with durable press chemicals. In order to break down the dyed materials, the researchers had to increase the amount of time and enzymes used. For fabrics treated with durable press chemicals, they had to use a chemical pre-treatment before adding the enzymes.

“The dye that you choose has a big impact on the potential degradation of the fabric,” said the study’s lead author Jeannie Egan, a graduate student at NC State. “Also, we found the biggest obstacle so far is the wrinkle-resistant finish. The chemistry behind that creates a significant block for the enzyme to access the cellulose. Without pre-treating it, we achieved less than 10% degradation, but after, with two enzyme doses, we were able to fully degrade it, which was a really exciting result.”

Researchers said the polyester could be recycled, while the slurry of cotton fragments could be valuable as an additive for paper or useful addition to composite materials. They’re also investigating whether the glucose could be used to make biofuels.

“The slurry is made of residual cotton fragments that resist a very powerful enzymatic degradation,” Salmon said. “It has potential value as a strengthening agent. For the glucose syrup, we’re collaborating on a project to see if we can feed it into an anaerobic digester to make biofuel. We’d be taking waste and turning it into bioenergy, which would be much better than throwing it into a landfill.”

The study, “Enzymatic textile fiber separation for sustainable waste processing,” was published in Resources, Environment and Sustainability. Co-authors included Siyan Wang, Jialong Shen, Oliver Baars and Geoffrey Moxley. Funding was provided by the Environmental Research and Education Foundation, Kaneka Corporation and the Department of Textile Engineering, Chemistry and Science at NC State.

Source:

North Carolina State University, Laura Oleniacz

Vadim Zharkov: https://youtu.be/x9gCrhIPaPM
28.02.2023

‘Smart’ Coating Could Make Fabrics into Protective Gear

Precisely applied metal-organic technology detects and captures toxic gases in air.

A durable copper-based coating developed by Dartmouth researchers can be precisely integrated into fabric to create responsive and reusable materials such as protective equipment, environmental sensors, and smart filters, according to a recent study.
 
The coating responds to the presence of toxic gases in the air by converting them into less toxic substances that become trapped in the fabric, the team reports in Journal of the American Chemical Society.

Precisely applied metal-organic technology detects and captures toxic gases in air.

A durable copper-based coating developed by Dartmouth researchers can be precisely integrated into fabric to create responsive and reusable materials such as protective equipment, environmental sensors, and smart filters, according to a recent study.
 
The coating responds to the presence of toxic gases in the air by converting them into less toxic substances that become trapped in the fabric, the team reports in Journal of the American Chemical Society.

The findings hinge on a conductive metal-organic technology, or framework, developed in the laboratory of corresponding author Katherine Mirica, an associate professor of chemistry. First reported in JACS in 2017, the framework was a simple coating that could be layered onto cotton and polyester to create smart fabrics the researchers named SOFT—Self-Organized Framework on Textiles. Their paper demonstrated that SOFT smart fabrics could detect and capture toxic substances in the surrounding environment.

For the newest study, the researchers found that—instead of the simple coating reported in 2017—they can precisely embed the framework into fabrics using a copper precursor that allows them to create specific patterns and more effectively fill in the tiny gaps and holes between threads.

The researchers found that the framework technology effectively converted the toxin nitric oxide into nitrite and nitrate, and transformed the poisonous, flammable gas hydrogen sulfide into copper sulfide. They also report that the framework’s ability to capture and convert toxic materials withstood wear and tear, as well as standard washing.
 
The versatility and durability the new method provides would allow the framework to be applied for specific uses and in more precise locations, such as a sensor on protective clothing, or as a filter in a particular environment, Mirica said.

“This new method of deposition means that the electronic textiles could potentially interface with a broader range of systems because they’re so robust,” she said. “This technological advance paves the way for other applications of the framework’s combined filtration and sensing abilities that could be valuable in biomedical settings and environmental remediation.”
The technique also could eventually be a low-cost alternative to technologies that are cost prohibitive and limited in where they can be deployed by needing an energy source, or—such as catalytic converters in automobiles—rare metals, Mirica said.
 
“Here we’re relying on an Earth-abundant matter to detoxify toxic chemicals, and we’re doing it without any input of outside energy, so we don’t need high temperature or electric current to achieve that function,” Mirica said.

Co-first author Michael Ko, initially observed the new process in 2018 as he attempted to deposit the metal-organic framework onto thin-film copper-based electrodes, Mirica said. But the copper electrodes would be replaced by the framework.

“He wanted it on top of the electrodes, not to replace them,” Mirica said. “It took us four years to figure out what was happening and how it was beneficial. It’s a very straightforward process, but the chemistry behind it is not and it took us some time and additional involvement of students and collaborators to understand that.”

The team discovered that the metal-organic framework “grows” over copper, replacing it with a material with the ability to filter and convert toxic gases, Mirica said. Ko and co-author Lukasz Mendecki, a postdoctoral scholar in the Mirica Group from 2017-18, investigated methods for applying the framework material to fabric in specific designs and patterns.

Co-first author Aileen Eagleton, who is also in the Mirica Group, finalized the technique by optimizing the process for imprinting the metal-organic framework onto fabric, as well as identifying how its structure and properties are influenced by chemical exposure and reaction conditions.

Future work will focus on developing new multifunctional framework materials and scaling up the process of embedding the metal-organic coatings into fabric, Mirica said.

Source:

Dartmouth / Textination

Aerogel (c) Outlast Technologies GmbH
31.01.2023

Aerogel: Frozen Smoke for Clothing and Work Safety

Comprised of up to 99.8 percent air, aerogel is the lightest solid in the world. The material, which is also called “frozen smoke” due to its appearance and physical properties, exhibits extremely low heat conductivity which exceeds other insulations many times over. This is why NASA has already been using aerogel for aerospace projects for many years.

Despite this, it has not been possible to bind the material to textiles in a high concentration and enable straightforward further processing over the roughly 90-year history of the material. Outlast Technologies GmbH has developed an innovative process - a patent has already been filed for -  for permanently adhering large amounts of aerogel to different media, like nonwoven fabric, felt and composites materials. Their original properties are retained throughout, so they can easily be further processed using conventional production methods.

Comprised of up to 99.8 percent air, aerogel is the lightest solid in the world. The material, which is also called “frozen smoke” due to its appearance and physical properties, exhibits extremely low heat conductivity which exceeds other insulations many times over. This is why NASA has already been using aerogel for aerospace projects for many years.

Despite this, it has not been possible to bind the material to textiles in a high concentration and enable straightforward further processing over the roughly 90-year history of the material. Outlast Technologies GmbH has developed an innovative process - a patent has already been filed for -  for permanently adhering large amounts of aerogel to different media, like nonwoven fabric, felt and composites materials. Their original properties are retained throughout, so they can easily be further processed using conventional production methods.

The fabrics sold under the Aersulate name are only 1 to 3 mm thick and achieve very high insulation values which are largely retained even under pressure and in moist conditions. Despite their high performance, they are still soft and can be used for shoes, clothing and work safety products, as well as for sleeping bags and technical applications.
 
“Thanks to its extraordinary physical properties, NASA has already been using aerogel for many years,” remarked Volker Schuster, Head of Research and Development at Outlast Technologies. “For example, for the insulation of its Mars rovers and for capturing dust from the tail of a comet during the Stardust mission,” he continued. Since the development of aerogel by American scientist and chemical engineer Samuel Stephens Kistler in 1931, no-one had been able to apply the versatile material to textiles in large amounts without changing their original properties, despite intensive research. This means that the products were often not only very rigid, but made processing with conventional production methods impossible due to their high degree of dust abrasion. With the newly developed Aersulate technology, which was presented for the first time in June 2022, the Heidenheim-based specialist for textile thermoregulation is opening a different chapter in insulation history.

High-performance insulation just 1 to 3 mm thick
“The consistency of aerogel can be best described as liquid dust particles which spread uncontrollably throughout a room within seconds thanks to their minimal thickness,” explained Schuster. “This is why processing is a big challenge.” Outlast Technologies has managed, after a development period of around five years, to bring an innovative process involving the adhering of aerogel between multiple layers of material to market maturity. Depending on the area of application, nonwoven fabric, felt and different composite materials can be used as the media. What is special here is that the properties of the respective textiles are not adversely affected by the Aersulate technology, meaning that they can easily be further processed with conventional means and under industrial conditions despite their acquired thermal properties.
 
As a silicate-based solid, aerogel is obtained from natural quartz sand, yet exhibits a density over 1,000 times lower than glass manufactured from the same raw material. The extraordinary thermo-insulating properties of the material are thanks to its extremely porous structure, which enables it to be composed of up to 99.8 percent air.
 
“One liter of aerogel weighs just 50 g,” explained Schuster. “Just 10 g of the material has the same surface area as a soccer field, though.” Thanks to these properties, Aersulate textiles exceed all other previously known insulation materials in terms of performance, despite the fact that they are only 1 to 3 mm thick. Tests carried out by the German Institute for Textile and Fiber Research in Denkendorf (DITF) using the Alambeta method showed that the thermal resistance of an Aersulate fleece is more than double that of a conventional fleece of the same thickness. Add to this the fact that the thermo-insulating properties of Aersulate products remain high despite pressure and wetness, while they decrease enormously with other conventional materials like felt and polyurethane foam (PU) under these conditions.

Work safety and functional clothing with Aersulate
Thanks to the textile medium, thin Aersulate products are especially suitable for the shoe and clothing industry, as well as all areas of work safety. The user benefits from different properties, depending on the intended use. “With a glove made of Aersulate just 1 mm thick, you can put your hand into boiling water without being scalded, for example,” explained Schuster. “The material’s extremely hydrophobic properties play quite literally into our hands here.” In the case of knee patches on work and functional pants, as well as shoes and soles, on the other hand, the material properties also become relevant when compression occurs. This is because the thermo-insulation properties of other materials would be reduced little by little due to moisture from the outside and sweat from the inside on the one hand, and by the continual influence of body weight on the other.
          
In addition to the human body, luggage and technical devices can also be protected from extreme temperatures and the effects of weather with Aersulate. For this purpose, corresponding cell phone or equipment pockets could be sewn into garments, for example, to maintain their battery life even at very cold outside temperatures and to safeguard the devices from overheating in case of high heat exposure. “With the broad range of possible textile medium materials, Aersulate is suitable for all applications requiring high thermal resistance on the one hand, where only a little space is available and both compression and moisture can be expected on the other,” said Schuster in summary.

Source:

Outlast Technologies / Textination

Photo Pixabay
10.01.2023

Fraunhofer: Optimized production of nonwoven masks

Producing infection control clothing requires a lot of energy and uses lots of material resources. Fraunhofer researchers have now developed a technology which helps to save materials and energy when producing nonwovens. A digital twin controls key manufacturing process parameters on the basis of mathematical modeling. As well as improving mask manufacturing, the ProQuIV solution can also be used to optimize the production parameters for other applications involving these versatile technical textiles, enabling manufacturers to respond flexibly to customer requests and changes in the market.

Producing infection control clothing requires a lot of energy and uses lots of material resources. Fraunhofer researchers have now developed a technology which helps to save materials and energy when producing nonwovens. A digital twin controls key manufacturing process parameters on the basis of mathematical modeling. As well as improving mask manufacturing, the ProQuIV solution can also be used to optimize the production parameters for other applications involving these versatile technical textiles, enabling manufacturers to respond flexibly to customer requests and changes in the market.

Nonwoven infection control masks were being used in their millions even before the COVID-19 pandemic and are regarded as simple mass-produced items. Nevertheless, the manufacturing process used to make them needs to meet strict requirements regarding precision and reliability. According to DIN (the German Institute for Standardization), the nonwoven in the mask must filter out at least 94 percent of the aerosols in the case of the FFP-2 mask and 99 percent in the case of the FFP-3 version. At the same time, the mask must let enough air through to ensure that the wearer can still breathe properly. Many manufacturers are looking for ways to optimize the manufacturing process. Furthermore, production needs to be made more flexible so that companies are able to process and deliver versatile nonwovens for a wide range of different applications and sectors.

ProQuIV, the solution developed by the Fraunhofer Institute for Industrial Mathematics ITWM in Kaiserslautern, fulfills both of these aims. The abbreviation “ProQuIV” stands for “Production and Quality Optimization of Nonwoven Infection Control Clothing” (Produktions- und Qualitätsoptimierung von Infektionsschutzkleidung aus Vliesstoffen). The basic idea is that manufacturing process parameters are characterized with regard to their impact on the uniformity of the nonwoven, and this impact is then linked to properties of the end product; for example, a protective mask. This model chain links all relevant parameters to an image analysis and creates a digital twin of the production process. The digital twin enables real-time monitoring and automatic control of nonwoven manufacturing and thus makes it possible to harness potential for optimization.

Dr. Ralf Kirsch, who works in the Flow and Material Simulation department and heads up the Filtration and Separation team, explains: “With ProQuIV, the manufacturers need less material overall, and they save energy. And the quality of the end product is guaranteed at all times.”

Nonwoven manufacturing with heat and air flow
Nonwovens for filtration applications are manufactured in what is known as the
meltblown process. This involves melting down plastics such as polypropylene and forcing them through nozzles so they come out in the form of threads referred to as filaments. The filaments are picked up on two sides by air flows which carry them forward almost at the speed of sound and swirl them around before depositing them on a collection belt. This makes the filaments even thinner: By the end of the process, their thickness is in the micrometer or even submicrometer range. They are then cooled, and binding agents are added in order to create the nonwoven. The more effectively the temperature, air speed and belt speed are coordinated with each other, the more uniform the distribution of the fibers at the end and therefore the more homogeneous the material will appear when examined under a transmitted light microscope. Lighter and darker areas can thereby be identified — this is referred to by experts as cloudiness. The Fraunhofer team has developed a method to measure a cloudiness index on the basis of image data. The light areas have a low fiber volume ratio, which means that they are less dense and have a lower filtration rate. Darker areas have a higher fiber volume and therefore a higher filtration rate. On the other hand, the higher air flow resistance in these areas means that they filter a smaller proportion of the air that is breathed in. A larger proportion of the air flows through the more open areas which have a less effective filtration effect.

Production process with real-time control
In the case of ProQuIV, the transmitted light images from the microscope are used to calibrate the models prior to use. The experts analyze the current condition of the textile sample and use this information to draw conclusions about how to optimize the system — for example, by increasing the temperature, reducing the belt speed or adjusting the strength of the air flows. “One of the key aims of our research project was to link central parameters such as filtration rate, flow resistance and cloudiness of a material with each other and to use this basis to generate a method which models all of the variables in the production process mathematically,” says Kirsch. The digital twin monitors and controls the ongoing production process in real time. If the system deviates slightly from where it should be — for example, if the temperature is too high — the settings are corrected automatically within seconds.

Fast and efficient manufacturing
“This means that it is not necessary to interrupt production, take material samples and readjust the machines. Once the models have been calibrated, the manufacturer can be confident that the nonwoven coming off the belt complies with the specifications and quality standards,” explains Kirsch. ProQuIV makes production much more efficient — there is less material waste, and the energy consumption is also reduced. Another advantage is that it allows manufacturers to develop new nonwoven-based products quickly — all they have to do is change the target specifications in the modeling and adjust the parameters. This enables production companies to respond flexibly to customer requests or market trends.

This might sound logical but can be quite complex when it comes to development. The way that the values for filtration performance and flow resistance increase, for example, is not linear at all, and they are not proportional to the fiber volume ratio either. This means that doubling the filament density does not result in double the filtration performance and flow resistance — the relationship between the parameters is much more complex than that. “This is precisely why the mathematical modeling is so important. It helps us to understand the complex relationship between the individual process parameters,” says ITWM researcher Kirsch. The researchers are able to draw on their extensive expertise in simulation and modeling for this work.

More applications are possible
The next step for the Fraunhofer team is to reduce the breathing resistance of the nonwovens for the wearer without impairing the protective effect. This is made possible by electrically charging the fibers and employing a principle similar to that of a feather duster. The electric charge causes the textile fabric to attract the tiniest of particles which could otherwise slip through the pores. For this purpose, the strength of the electrostatic charge is integrated into the modeling as a parameter.

The Fraunhofer researchers’ plans for the application of this method extend far beyond masks and air filters. Their technology is generally applicable to the production of nonwovens — for example, it can also be used in materials for the filtration of liquids. Furthermore, ProQuIV methods can be used to optimize the manufacture of nonwovens used in sound-insulating applications.

Source:

Fraunhofer Institute for Industrial Mathematics ITWM

(c) DITF
20.12.2022

New 3D printing process for sustainable fiber composite components

Nature works often with fiber composites. The construction principles of nature require little material and energy and thus ensure the survival of animals and plant species. Examples include wood, plant stalks, chitinous shells, bones or tissues such as tendons and skin. Mussel shells or spider silk are also composite tissues. We can take advantage of these principles to design and manufacture bio-based, sustainable fiber reinforced composites, which are currently in high demand. Bio-based fiber reinforced composites consist of natural fibers or cellulose fibers embedded in a bio-based matrix. The bio-based components offer properties comparable to those of commonly used glass fiber composites. The German Institutes of Textile and Fiber Research (DITF), together with Arburg GmbH + Co KG, are developing an energy- and material-efficient 3D printing process for manufacturing of such lightweight bio-based fiber composites.

Nature works often with fiber composites. The construction principles of nature require little material and energy and thus ensure the survival of animals and plant species. Examples include wood, plant stalks, chitinous shells, bones or tissues such as tendons and skin. Mussel shells or spider silk are also composite tissues. We can take advantage of these principles to design and manufacture bio-based, sustainable fiber reinforced composites, which are currently in high demand. Bio-based fiber reinforced composites consist of natural fibers or cellulose fibers embedded in a bio-based matrix. The bio-based components offer properties comparable to those of commonly used glass fiber composites. The German Institutes of Textile and Fiber Research (DITF), together with Arburg GmbH + Co KG, are developing an energy- and material-efficient 3D printing process for manufacturing of such lightweight bio-based fiber composites.

In fiber composites, which occur naturally, reinforcing fibers such as collagen or cellulose fibrils are embedded in a matrix of lignin, hemicellulose or collagen. The fiber strands align with the stress patterns. Tissues are formed mostly via solution-based physio-chemical processes that take place at ambient temperature. Similar to nature, new 3D printing processes with continuous fiber reinforcement also allow the deposition of fiber strands in the right place (topology optimization) and in the appropriate direction in accordance to the load. However, natural fibers such as cellulose fibers are sensitive to higher temperatures. Therefore, they cannot be processed in the commonly employed thermoplastic 3D printing process.

The result of the research work is 3D-printed fiber composite components consisting of cellulose continuous fibers embedded in a cellulose-based matrix. Newly developed 3D-printing process enables to manufacture the composites at ambient temperature. This means that - as in nature - the material and component can be produced simultaneously in a single operation at ambient temperature.

The cellulose fiber strand is first stabilized with a binder for processing in the printer. The specially designed print head transforms the binder into a matrix with which the cellulose continuous fibers are encased. Since the cellulose fibers and the matrix have similar chemical structures, the composite component is particularly stable. The mechanical properties, such as breaking strength, are exceptionally good. The solution-based and energy-efficient manufacturing method developed by the research team can also be used in other composite materials manufacturing processes. It is particularly suitable for processing temperature-sensitive materials that are in high demand, such as natural or cellulose fibers.

The " CellLoes-3D-Druck" research project is funded by the German Federal Ministry of Education and Research as part of the "Biologisierung der Technik" ideas competition.

Source:

Deutsche Institute für Textil- und Faserforschung Denkendorf

(c) Fraunhofer IKTS
02.08.2022

Fraunhofer technology: High-tech vest monitors lung function

Patients with severe respiratory or lung diseases require intensive treatment and their lung function needs to be monitored on a continuous basis. As part of the Pneumo.Vest project, Fraunhofer researchers have developed a technology whereby noises in the lungs are recorded using a textile vest with integrated acoustic sensors. The signals are then converted and displayed visually using software. In this way, patients outside of intensive care units can still be monitored continuously. The technology increases the options for diagnosis and improves the patient’s quality of life.

For over 200 years, the stethoscope has been a standard tool for doctors and, as such, is a symbol of the medical profession. In television hospital dramas, doctors are seen rushing through the halls with a stethoscope around their neck. Experienced doctors do indeed use them to listen very accurately to heartbeats and the lungs and, as a result, to diagnose illnesses.

Patients with severe respiratory or lung diseases require intensive treatment and their lung function needs to be monitored on a continuous basis. As part of the Pneumo.Vest project, Fraunhofer researchers have developed a technology whereby noises in the lungs are recorded using a textile vest with integrated acoustic sensors. The signals are then converted and displayed visually using software. In this way, patients outside of intensive care units can still be monitored continuously. The technology increases the options for diagnosis and improves the patient’s quality of life.

For over 200 years, the stethoscope has been a standard tool for doctors and, as such, is a symbol of the medical profession. In television hospital dramas, doctors are seen rushing through the halls with a stethoscope around their neck. Experienced doctors do indeed use them to listen very accurately to heartbeats and the lungs and, as a result, to diagnose illnesses.

Now, the stethoscope is getting some help. As part of the Pneumo.Vest project, researchers of the Fraunhofer Institute for Ceramic Technologies and Systems IKTS at the Berlin office have developed a textile vest with integrated acoustic sensors, presenting a high-performance addition to the traditional stethoscope. Piezoceramic acoustic sensors have been incorporated into the front and back of the vest to register any noise produced by the lungs in the thorax, no matter how small. A software program records the signals and electronically amplifies them, while the lungs are depicted visually on a display. As the software knows the position of each individual sensor, it can attribute the data to its precise location. This produces a detailed acoustic and optical picture of the ventilation situation of all parts of the lungs. Here is what makes it so special: As the system collects and stores the data permanently, examinations can take place at any given time and in the absence of hospital staff. Pneumo.Vest also indicates the status of the lungs over a period of time, for example over the previous 24 hours. Needless to say, traditional auscultation can also be carried out directly on the patients. However, instead of carrying out auscultation manually at different points with a stethoscope, a number of sensors are used simultaneously.

“Pneumo.Vest is not looking to make the stethoscope redundant and does not replace the skills of experienced pneumologists. However, auscultation or even CT scans of the lungs only ever present a snapshot at the time of the examination. Our technology provides added value because it allows for the lungs to be monitored continuously in the same way as a long-term ECG, even if the patient is not attached to machines in the ICU but has instead been admitted to the general ward,” explains Ralf Schallert, project manager at Fraunhofer IKTS.

Machine learning algorithms aid with diagnosis
Alongside the acoustic sensors, the software is at the core of the vest. It is responsible for storing, depicting and analyzing the data. It can be used by the doctor to view the acoustic events in specific individual areas of the lungs on the display. The use of algorithms in digital signal processing enables a targeted evaluation of acoustic signals. This means it is possible, for example, to filter out heartbeats or to amplify characteristic frequency ranges, making lung sounds, such as rustling or wheezing, much easier to hear.

On top of this, the researchers at Fraunhofer IKTS are developing machine learning algorithms. In the future, these will be able to structure and classify complex ambient noises in the thorax. Then, the pneumologist will carry out the final assessment and diagnosis.

Discharge from the ICU
Patients can also benefit from the digital sensor alternative. When wearing the vest, they can recover without requiring constant observation from medical staff. They can transfer to the general ward and possibly even be sent home and move about more or less freely. Despite this, the lungs are monitored continuously, and any sudden deterioration can be reported to medical personnel straight away.

The first tests with staff at the University Clinic for Anesthesiology and Intensive Therapy at the University of Magdeburg have shown that the concept is successful in practice. “The feedback from doctors was overwhelmingly positive. The combination of acoustic sensors, visualization and machine learning algorithms will be able to reliably distinguish a range of different lung sounds,” explains Schallert. Dr. Alexander Uhrig from Charité – Universitätsmedizin Berlin is also pleased with the technology. The specialist in infectiology and pneumology at the renowned Charité hospital was one of those who initiated the idea: “Pneumo.Vest addresses exactly what we need. It serves as an instrument that expands our diagnostic options, relieves the burden on our hospital staff and makes hospital stays more pleasant for patients.”

The technology was initially designed for respiratory patients, but it also works well for people in care facilities and for use in sleep laboratories. It can also be used to train young doctors in auscultation.

Increased need for clinical-grade wearables
With Pneumo.Vest, the researchers at Fraunhofer IKTS have developed a product that is cut out for the increasingly strained situation at hospitals. In Germany, 385,000 patients with respiratory or lung diseases require inpatient treatment every year. Over 60 percent are connected to a ventilator for more than 24 hours. This figure does not account for the current increase in respiratory patients due to the COVID-19 pandemic. As a result of increasing life expectancy, the medical industry also expects the number of older patients with breathing problems to increase. With the help of technology from Fraunhofer IKTS, the burden on hospitals and, in particular, costly ICUs can be relieved as their beds will no longer be occupied for quite as long.

It should be added that the market for such clinical-grade wearables is growing rapidly. These are compact medical devices that can be worn directly on the body to measure vital signs such as heartbeat, blood oxygen saturation, respiratory rate or skin temperature. As a medical device that can be used flexibly, Pneumo.Vest fits in perfectly with this development. But do not worry: Doctors will still be using the beloved stethoscope in the future.

Fraunhofer “M³ Infekt” cluster project
Pneumo.Vest is just one part of the extensive M³ Infekt cluster project. Its objective is to develop monitoring systems for the decentralized monitoring of patients. The current basis of the project is the treatment of COVID-19 patients. With the SARS-CoV2 virus, it is common for even mild cases to suddenly deteriorate significantly. By continuously monitoring vital signs, any deterioration in condition can be quickly identified and prompt measures for treatment can be taken.

M3 Infekt can also be used for a number of other symptoms and scenarios. The systems have been designed to be modular and multimodal so that biosignals such as heart rate, ECG, oxygen saturation, or respiratory rate and volume can be measured, depending on the patient and illness.

A total of ten Fraunhofer institutes are working on the cluster project under the leadership of the Fraunhofer Institute for Integrated Circuits IIS in Dresden. Klinikum Magdeburg, Charité – Universitätsmedizin Berlin and the University Hospitals of Erlangen and Dresden are involved as clinical partners.

Source:

Fraunhofer Institute for Ceramic Technology and Systems IKTS

Photo: pixabay
17.05.2022

The industrial future needs climate-neutral process heat

IN4climate.NRW publishes discussion paper

Not only private households, but above all industrial companies have a high demand for heat. On the way to climate neutrality, greater focus must be placed on the supply of process heat to the industry - especially in the industrial state of North Rhine-Westphalia (NRW). This is shown by the discussion paper of the climate protection think tank IN4climate.NRW.

In 2020, process heat accounted for a large percentage of industrial energy demand - 67 percent of the energy consumed by German industry - and is still predominantly supplied by fossil fuels (BMWi 2021a). That's almost 20 percent of Germany's total energy demand. No wonder: Whether glass, metal, cement or paper are melted, forged, fired or dried - all these processes require process heat. And in some cases up to a temperature of 3,000 °C.

IN4climate.NRW publishes discussion paper

Not only private households, but above all industrial companies have a high demand for heat. On the way to climate neutrality, greater focus must be placed on the supply of process heat to the industry - especially in the industrial state of North Rhine-Westphalia (NRW). This is shown by the discussion paper of the climate protection think tank IN4climate.NRW.

In 2020, process heat accounted for a large percentage of industrial energy demand - 67 percent of the energy consumed by German industry - and is still predominantly supplied by fossil fuels (BMWi 2021a). That's almost 20 percent of Germany's total energy demand. No wonder: Whether glass, metal, cement or paper are melted, forged, fired or dried - all these processes require process heat. And in some cases up to a temperature of 3,000 °C.

In the discussion paper "Process heat for a climate-neutral industry (Prozesswärme für eine klimaneutrale Industrie)", IN4climate.NRW formulates approaches and recommendations for action for a process heat transition. A total of thirteen partners of the initiative have signed the paper.

Samir Khayat, Managing Director of NRW.Energy4-Climate: "The switch to sustainable process heat supply is one of the decisive factors in ensuring that the transformation of industry can succeed. With the IN4climate.NRW initiative, we are bringing together the expertise from science, politics as well as industry, and developing concrete strategies to put climate neutrality in industry into practice."

Various figures illustrate the need for action: Only 6 percent of the energy required for process heat has so far been covered by renewable energies. Electricity also currently accounts for only 8 percent - as an energy source, it is still far from emission-free in today's electricity mix, but must become so in the future through the switch to 100 percent renewables.

NRW alone needs 40 percent of the process heat required by the whole of Germany
Tania Begemann, Project Manager Industry and Production at NRW.Energy4Climate and author of the paper: "The sustainable conversion of process heat has always been an important and urgent topic at IN4climate.NRW, but it becomes even more explosive in times of a global energy crisis. It is estimated that NRW alone requires 40 percent of the process heat required by the whole of Germany. In order to remain economically strong and an industrial state in the long term, it is therefore of particular importance for NRW to become independent of fossil process heat sources in the near future. We would like to draw attention to this with this paper. At the same time, this enormous challenge also offers NRW the opportunity to become a pioneer."

How can this be accomplished? The discussion paper shows central approaches and recommendations for action:

  • Increase efficiency: The development and use of high-temperature heat pumps should be specifically promoted within the framework of pilot plants and concepts. In addition, companies should be supported in the development and implementation of concepts that minimize process temperatures and use waste heat within the company.
  • Promote renewable heat sources: Local, renewable energy sources such as deep geothermal energy and solar thermal energy can be an important component of climate-neutral process heat supply and at the same time reduce the reliance on energy imports. Where renewables can supply industrial heating needs, they should be used. These forms of energy should therefore be supported in a targeted manner through inquiries and tenders.
  • Increase renewable electricity: The electrification of processes and applications is the prerequisite for the energy transition. Expanding renewable power generation along with a solid power grid, creating competitive prices for green power, and developing flexible systems are therefore key tasks.
  • Promote storable alternative energy sources: To be able to generate process heat even when renewable energies are not available, industry needs large quantities of storable energy carriers. In particular, sustainable hydrogen must be available at competitive prices and the necessary conditions, such as a transport and storage infrastructure, must be created. In addition to hydrogen, biomass is a valuable and storable energy carrier and raw material at the same time. This limited resource must therefore be used in a targeted and efficient manner.

The climate-neutral generation of process heat is of great importance for the whole of Germany, but especially for the industrial state of North Rhine-Westphalia, and at the same time represents a major challenge. The heat transition in industry requires an overall systemic and supraregional view and strategy development. On the one hand, such strategies should take into account the interaction of different sectors. On the other hand, they should include all heat requirements - from buildings to industry. In this paper, decision-makers from politics, industry and society will find initial reference points and impulses for this important, common task.

The paper was developed by the IN4climate.NRW initiative under the umbrella of the NRW.Energy4Climate state organization. It is supported by the institutes Fraunhofer UMSICHT, RWTH Aachen (Chair of Technical Thermodynamics), the VDZ research institute as well as the Wuppertal Institute, the companies Amprion, Currenta, Deutsche Rohstofftechnik (German raw material technology - RHM Group), Georgsmarienhütte, Kabel Premium Pulp and Paper, Lhoist, Pilkington Germany (NSG Group) and Speira as well as the Federal Association of the German Glass Industry.

Source:

Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT

(c) Vincentz Network GmbH & Co. KG / ALTENPFLEGE
26.04.2022

ALTENPFLEGE 2022: Intelligently equipped rooms for more independence in old age

Most people want to live as independently as possible in old age. Exhibitors at the industry's leading trade fair ALTENPFLEGE from April 26 to 28 in Essen, Germany will be showing how senior facilities with modern interior design and smart equipment meet this need.

Demand for forms of housing such as service living is on the rise. Studies predict a need for around 540,000 new service living units in the coming years. One of the major trends at this year's 32nd edition of the Altenpflege trade fair is how senior facilities are meeting the rapidly growing demand with flexible room design and digital support. They can be seen in the Aveneo special show, including intelligent systems for stove shut-off, lighting control and room temperature, as well as for fall sensors and emergency calls.

Most people want to live as independently as possible in old age. Exhibitors at the industry's leading trade fair ALTENPFLEGE from April 26 to 28 in Essen, Germany will be showing how senior facilities with modern interior design and smart equipment meet this need.

Demand for forms of housing such as service living is on the rise. Studies predict a need for around 540,000 new service living units in the coming years. One of the major trends at this year's 32nd edition of the Altenpflege trade fair is how senior facilities are meeting the rapidly growing demand with flexible room design and digital support. They can be seen in the Aveneo special show, including intelligent systems for stove shut-off, lighting control and room temperature, as well as for fall sensors and emergency calls.

Future tenants or buyers of serviced apartments are prepared to invest specifically in their own living environment (source: Terragon study 2021). The focus is on a feel-good atmosphere, a high level of security and the option of using care services if required. "This can be facilitated by a cleverly thought-out arrangement of the rooms within a serviced apartment, for example by arranging the bathroom and bedroom right next to each other and making the wall with the washbasin rotatable," explains Carolin Pauly, managing director of Universal Rooms, which considers itself to be the interface between the wishes of the operators and the products in the serviced apartment market. "The furniture and furnishings industry is called upon to design modern collections with hidden product features that make life easier in old age," Pauly demands. This could be, for example, a grab handle built into the washbasin or a dining table that can be accessed by a wheelchair.

Lighting management also plays an important role. It should convey a sense of well-being and security as well as provide orientation and safety. Age-related clinical pictures in particular place high demands on lighting. Here, lighting systems that simulate the natural day and night rhythm can provide help.

Living, care and digitalization combined
The Chief Executive Officer of the Evangelische Heimstiftung (EHS - Evangelical Home Foundation), Bernhard Schneider, sees "an individually and comfortably furnished apartment that uses intelligent technology to provide a great deal of security and self-determination" as the senior living of the future. "I am certain: In the future, in a sector-free setting, we will have to understand housing, nursing and care, and digitalization even more strongly as building blocks that can be combined as needed."

According to Schneider, this starts with housing: In a nursing apartment or an assisted living apartment, in a shared apartment or other form of communal living, in a residence or an intergenerational project. All forms of housing should be well integrated into the neighborhood - this requires reliable, financed advisory structures, for example through neighborhood managers. In addition, there is care, support and assistance, in the form of day or night care, a mobile service or volunteers. "And technology, for example through our Aladien system, i.e. with intelligent home emergency call, fall sensors, stove shut-off, roller shutters and light control, video door telephony, etc. In the future, Aladien will evolve into a service robot," predicts Schneider.

This makes it possible for people to live a self-determined life and participate in society, even in old age. That's what people want, he says: a pleasant living environment, social contacts, cultural offerings and the certainty that someone will take care of them if necessary. "What we need for this is political commitment in the form of an ambitious funding program for modern forms of housing in old age," demands the EHS CEO. This would not only help the older generation, but young families could also benefit because this would free up the far too spacious apartments and terraced houses of the older generation for them.


ALTENPFLEGE – Trade fair and congress for the care industry since 1990
The traditional leading trade show for the care industry has so far been held alternately in Hanover and Nuremberg. From this year it alternates between Essen and Nuremberg. It covers all segments of professional geriatric care: services and products for care and therapy, occupation and education, IT and management, nutrition and home economics, textiles and hygiene as well as space and technology. In more than 30 lecture blocks, the accompanying trade congress covers the current topics of the industry, such as digitalization, the future of professional nursing care, hospice and palliative care, training or the new collectively agreed payment under the Healthcare Development Act (Gesundheitsversorgungsweiterentwicklungsgesetz - GVWG).

(c) Empa
05.04.2022

In the heat of the wound: Smart bandage

A bandage that releases medication as soon as an infection starts in a wound could treat injuries more efficiently. Empa researchers are currently working on polymer fibers that soften as soon as the environment heats up due to an infection, thereby releasing antimicrobial drugs.

It is not possible to tell from the outside whether a wound will heal without problems under the dressing or whether bacteria will penetrate the injured tissue and ignite an inflammation. To be on the safe side, disinfectant ointments or antibiotics are applied to the wound before the dressing is applied. However, these preventive measures are not necessary in every case. Thus, medications are wasted and wounds are over-treated.

A bandage that releases medication as soon as an infection starts in a wound could treat injuries more efficiently. Empa researchers are currently working on polymer fibers that soften as soon as the environment heats up due to an infection, thereby releasing antimicrobial drugs.

It is not possible to tell from the outside whether a wound will heal without problems under the dressing or whether bacteria will penetrate the injured tissue and ignite an inflammation. To be on the safe side, disinfectant ointments or antibiotics are applied to the wound before the dressing is applied. However, these preventive measures are not necessary in every case. Thus, medications are wasted and wounds are over-treated.

Even worse, the wasteful use of antibiotics promotes the emergence of multi-resistant germs, which are an immense problem in global healthcare. Empa researchers at the two Empa laboratories Biointerfaces and Biomimetic Membranes and Textiles in St. Gallen want to change this. They are developing a dressing that autonomously administers antibacterial drugs only when they are really needed.

The idea of the interdisciplinary team led by Qun Ren and Fei Pan: The dressing should be "loaded" with drugs and react to environmental stimuli. "In this way, wounds could be treated as needed at exactly the right moment," explains Fei Pan. As an environmental stimulus, the team chose a well-known effect: the rise in temperature in an infected, inflamed wound.

Now the team had to design a material that would react appropriately to this increase in temperature. For this purpose, a skin-compatible polymer composite was developed made of several components: acrylic glass (polymethyl methacrylate, or PMMA), which is used, for example, for eyeglass lenses and in the textile industry, and Eudragit, a biocompatible polymer mixture that is used, for example, to coat pills. Electrospinning was used to process the polymer mixture into a fine membrane of nanofibers. Finally, octenidine was encapsulated in the nanofibers as a medically active component. Octenidine is a disinfectant that acts quickly against bacteria, fungi and some viruses. In healthcare, it can be used on the skin, on mucous membranes and for wound disinfection.

Signs of inflammation as triggers
As early as in the ancient world, the Greek physician Galen described the signs of inflammation. The five Latin terms are still valid today: dolor (pain), calor (heat), rubor (redness), tumor (swelling) and functio laesa (impaired function) stand for the classic indications of inflammation. In an infected skin wound, local warmth can be as high as five degrees. This temperature difference can be used as a trigger: Suitable materials change their consistency in this range and can release therapeutic substances.

Shattering glove
"In order for the membrane to act as a "smart bandage" and actually release the disinfectant when the wound heats up due to an infection, we put together the polymer mixture of PMMA and Eudragit in such a way that we could adjust the glass transition temperature accordingly," says Fei Pan. This is the temperature, at which a polymer changes from a solid consistency to a rubbery, toughened state. Figuratively, the effect is often described in reverse: If you put a rubber glove in liquid nitrogen at –196 degrees, it changes its consistency and becomes so hard that you can shatter it like glass with one blow.

The desired glass transition temperature of the polymer membrane, on the other hand, was in the range of 37 degrees. When inflammation kicks in and the skin heats up above its normal temperature of 32 to 34 degrees, the polymer changes from its solid to a softer state. In laboratory experiments, the team observed the disinfectant being released from the polymer at 37 degrees – but not at 32 degrees. Another advantage: The process is reversible and can be repeated up to five times, as the process always "switches itself off" when it cools down. Following these promising initial tests, the Empa researchers now want to fine-tune the effect. Instead of a temperature range of four to five degrees, the smart bandage should already switch on and off at smaller temperature differences.

Smart and unsparing
To investigate the efficacy of the nanofiber membranes against wound germs, further laboratory experiments are now in the pipeline. Team leader Qun Ren has long been concerned with germs that nestle in the interface between surfaces and the environment, such as on a skin wound. "In this biological setting, a kind of no man's land between the body and the dressing material, bacteria find a perfect biological niche," says the Empa researcher. Infectious agents such as staphylococci or Pseudomonas bacteria can cause severe wound healing disorders. It was precisely these wound germs that the team allowed to become acquainted with the smart dressing in the Petri dish. And indeed: The number of bacteria was reduced roughly 1000-fold when octenidine was released from the smart dressing. "With octenidine, we have achieved a proof of principle for controlled drug release by an external stimulus," said Qun Ren. In future, she said, the technology could be applied to other types of drugs, increasing the efficiency and precision in their dosage.

The smart dressing
Empa researchers are working in interdisciplinary teams on various approaches to improve medical wound treatment. For example, liquid sensors on the outside of the dressing are to make it visible when a wound is healing poorly by changing their color. Critical glucose and pH values serve as biomarkers.

To enable bacterial infections to be contained directly in the wound, the researchers are also working on a polymer foam loaded with anti-inflammatory substances and on a skin-friendly membrane made of plant material. The cellulose membrane is equipped with antimicrobial protein elements and kills bacteria extremely efficiently in laboratory tests.

Moreover, digitalization can achieve more economical and efficient dosages in wound care: Empa researchers are developing digital twins of the skin that allow control and prediction of the course of a therapy using real-time modeling.

Further information:
Prof. Dr. Katharina
Maniura Biointerfaces
Phone +41 58 765 74 47
Katharina.Maniura@empa.ch

Prof. Dr. René Rossi
Biomimetic Membranes and Textiles
Phone +41 58 765 77 65
Rene.rossi@empa.ch

Source:

EMPA, Andrea Six

Photo: pixabay
15.02.2022

Advanced Fibers: When damaged ropes change color

High-performance fibres that have been exposed to high temperatures usually lose their mechanical properties undetected and, in the worst case, can tear precisely when lives depend on them. For example, safety ropes used by fire brigades or suspension ropes for heavy loads on construction sites. Empa researchers have now developed a coating that changes color when exposed to high temperatures through friction or fire.

The firefighter runs into the burning building and systematically searches room by room for people in need of rescue. Attached to him is a safety rope at the other end of which his colleagues are waiting outside in front of the building. In an emergency - should he lose consciousness for any reason - they can pull him out of the building or follow him into the building for rescue. However, if this rope has been exposed to excessive heat during previous operations, it may tear apart. This means danger to life!

High-performance fibres that have been exposed to high temperatures usually lose their mechanical properties undetected and, in the worst case, can tear precisely when lives depend on them. For example, safety ropes used by fire brigades or suspension ropes for heavy loads on construction sites. Empa researchers have now developed a coating that changes color when exposed to high temperatures through friction or fire.

The firefighter runs into the burning building and systematically searches room by room for people in need of rescue. Attached to him is a safety rope at the other end of which his colleagues are waiting outside in front of the building. In an emergency - should he lose consciousness for any reason - they can pull him out of the building or follow him into the building for rescue. However, if this rope has been exposed to excessive heat during previous operations, it may tear apart. This means danger to life!

And up to now there has been no way of noticing this damage to the rope. 2021 a team of researchers from Empa and ETH Zurich has developed a coating which changes color due to the physical reaction with heat, thus clearly indicating whether a rope will continue to provide the safety it promises in the future.

Researchers from ETH Zurich and Empa developed a coating system in 2018 as part of a Master's thesis, which the Empa team was now able to apply to fibers. "It was a process involving several steps," says Dirk Hegemann from Empa's Advances Fibers lab. The first coatings only worked on smooth surfaces, so the method first had to be adapted so that it would also work on curved surfaces. Empa has extensive know-how in the coating of fibers - Hegemann and his team have already developed electrically conductive fibers in the past. The so-called sputtering process has now also been successfully applied to the latest coating.

Three layers are required to ensure that the fiber actually changes color when heated. The researchers apply silver to the fibre itself, in this case PET (i.e. polyester) and VectranTM, a high-tech fibre. This serves as a reflector - in other words, as a metallic base layer. This is followed by an intermediate layer of titanium nitrogen oxide, which ensures that the silver remains stable. And only then follows the amorphous layer that causes the color change: Germanium-antimony tellurium (GST), which is just 20 nanometers thick. When this layer is exposed to elevated temperatures, it crystallizes, changing the color from blue to white. The colour change is based on a physical phenomenon known as interference. Two different waves (e.g. light) meet and amplify or weaken each other. Depending on the chemical composition of the temperature-sensitive layer, this color change can be adjusted to a temperature range between 100 and 400 degrees and thus adapted to the mechanical properties of the fiber type.

Tailor-made solutions
The possible areas of application for the colour-changing fibres are still open, and Hegemann is currently looking for possible project partners. In addition to safety equipment for firefighters or mountaineers, the fibres can also be used for load ropes in production facilities, on construction sites, etc. In any case, research on the subject is far from complete. At present, it is not yet possible to store the fibers for long periods of time without losing their functionality. "Unfortunately, the phase-change materials oxidize over the course of a few months," says Hegemann. This means that the corresponding phase change - crystallization - no longer takes place, even with heat, and the rope thus loses its "warning signal". In any case, it has been proven that the principle works, and durability is a topic for future research, says Hegemann. "As soon as the first partners from industry register their interest in our own products, the fibers can be further optimized according to their needs".

Information:
Dr. Dirk Hegemann
Advanced Fibers
Tel. +41 58 765 7268
Dirk.Hegemann@empa.ch

More information:
Empa Fibers Ropes temperature
Source:

EMPA, Andrea Six

(c) Empa
08.02.2022

Early detection of dementia with a textile belt

Alzheimer's and other dementias are among the most widespread diseases today. Diagnosis is complex and can often only be established with certainty late in the course of the disease. A team of Empa researchers, together with clinical partners, is now developing a new diagnostic tool that can detect the first signs of neurodegenerative changes using a sensor belt.

Forgetfulness and confusion can be signs of a currently incurable ailment: Alzheimer's disease. It is the most common form of dementia that currently affect around 50 million people worldwide. It mainly afflicts older people. The fact that this number will increase sharply in the future is therefore also related to the general increase in life expectancy.

Alzheimer's and other dementias are among the most widespread diseases today. Diagnosis is complex and can often only be established with certainty late in the course of the disease. A team of Empa researchers, together with clinical partners, is now developing a new diagnostic tool that can detect the first signs of neurodegenerative changes using a sensor belt.

Forgetfulness and confusion can be signs of a currently incurable ailment: Alzheimer's disease. It is the most common form of dementia that currently affect around 50 million people worldwide. It mainly afflicts older people. The fact that this number will increase sharply in the future is therefore also related to the general increase in life expectancy.

If dementia is suspected, neuropsychological examinations, laboratory tests and demanding procedures in the hospital are required. However, the first neurodegenerative changes in the brain occur decades before a reduced cognitive ability becomes apparent. Currently, these can only be detected by expensive or invasive procedures. These methods are thus not suitable for extensive early screenings on a larger scale. Empa researchers are working with partners from the Cantonal Hospital and the Geriatric Clinic in St. Gallen on a non-invasive diagnostic method that detects the early processes of dementia.

Signs in the unconscious
For the new method, the researchers Patrick Eggenberger and Simon Annaheim from Empa's Biomimetic Membranes and Textiles lab in St. Gallen relied on a sensor belt that has already been used successfully for ECG measurements and has now been equipped with sensors for other relevant parameters such as body temperature and gait pattern. This is because long before memory starts to deteriorate in dementia, subtle changes appear in the brain, which are expressed through unconscious bodily reactions.

These changes can only be recorded precisely when measurements are taken over a longer period of time, though. "It should be possible to integrate the long-term measurements into everyday life," explains Simon Annaheim. Skin-friendly and comfortable monitoring systems are essential for measurements that are suitable for everyday use. The diagnostic belt is therefore based on flexible sensors with electrically conductive or light-conducting fibers as well as sensors for motion and temperature measurement.

To enable such long-term measurements to be used for monitoring neurocognitive health, the researchers are integrating the collected data into in-house developed mathematical models. The goal: an early warning system that can estimate the progression of cognitive impairment. Another advantage is that the data measurements can be integrated into telemonitoring solutions and can thus improve patient care in their familiar environment.

Suspicious monotony
The human body is able to keep its temperature constant in a range of 1 degree Celsius. The values naturally oscillate in the course of the day. This daily rhythm changes with age and is conspicuous in neurodegenerative diseases such as dementia or Parkinson's disease. In Alzheimer's patients, for example, the core body temperature is elevated by up to 0.2 degrees Celsius. At the same time, the spikes in daily temperature fluctuations are dampened.

In a study, the researchers have now been able to show that altered skin temperature readings measured with the sensor belt actually provide an indication of the cognitive performance of test subjects – and can do so well before dementia develops. The test subjects in the study included healthy people with or without mild brain impairment. This mild cognitive impairment (MCI) does not represent a disability in everyday life, but it is considered a possible precursor to Alzheimer's disease. The subjects took part in long-term measurements and neuropsychological tests. It was found that a lower body temperature, which fluctuated more throughout the day, was linked to a better cognitive performance. In individuals with MCI, body temperature varied less and was slightly elevated overall.

The heartbeat is also subject to natural variations that show how our nervous system adapts to sudden challenges. The small silence between two heartbeats, about one second in duration, has great significance for our health: If this pause always remains the same, our nervous system is not at its best.

A study by researchers from ETH Zurich determined that poorer measurements in older, healthy people can be improved within six months through cognitive-motor dance training. In these "exergames," the test subjects imitated sequences of steps from a video. In contrast, participants who instead only trained in straight lines on a treadmill, but also trained their memory, benefited less.

"The point is to intervene early with appropriate training as soon as the first negative signs can be measured," says Patrick Eggenberger. "With our sensor system, any improvements in cognitive performance can be tracked through movement-based forms of therapy." Studies with long-term monitoring will now be used to clarify how the sensor measurements can be used to predict the progression of mild brain disorders.

Further information
Dr. Simon Annaheim
Biomimetic Membranes and Textiles   
Phone +41 58 765 77 68
Simon.Annaheim@empa.ch

More information:
Empa Membrane Medical & Healthcare
Source:

EMPA, Andrea Six

(c) PERFORMANCE DAYS
16.11.2021

PERFORMANCE DAYS 2021: Hybrid Event in December

From December 1 to 2, 2021, the industry will meet up again live at the trade fair center in Munich. Trade visitors, industry insiders and experts can look forward to inter-personal exchanges, intensive networking, exciting fabric innovations and various other program highlights. The fair will go ahead in strict compliance with the current official hygiene regulations and in close cooperation with the Messe München authorities. Planned as a hybrid event, PERFORMANCE DAYS offers the possibility to follow what is on offer digitally.

From December 1 to 2, 2021, the industry will meet up again live at the trade fair center in Munich. Trade visitors, industry insiders and experts can look forward to inter-personal exchanges, intensive networking, exciting fabric innovations and various other program highlights. The fair will go ahead in strict compliance with the current official hygiene regulations and in close cooperation with the Messe München authorities. Planned as a hybrid event, PERFORMANCE DAYS offers the possibility to follow what is on offer digitally.

Live in Munich: PERFORMANCE DAYS in Hall A6
In Hall A6 on the grounds of the New Trade Center in Munich, trade visitors can look forward to an extensive portfolio of exhibitors showcasing their latest functional textiles and fabric innovations for the upcoming winter season, winter 2023/24. Exhibitors who are unable to present their highlights on site can also be accessed via the PERFORMANCE DAYS LOOP digital platform throughout the course of the fair. As part of the newly developed “remote booths” concept, trade visitors will for the first time also find collections from exhibitors who cannot be in Munich in person for the trade show. Interactive exchanges via chat, call or video call is planned.

Two further PERFORMANCE DAYS fairs are planned as live events: The Functional Fabric Fair by PERFORMANCE DAYS in Portland, Oregon, USA on November 17-18, 2021 and Functional Textiles Shanghai by PERFORMANCE DAYS on December 6-7, 2021. Registration is open at www.functionalfabricfair.com/ and www.functionaltextilesshanghai.com/

PERFORMANCE FORUM together with USA Fair
As part of the PERFORMANCE FORUM, a select jury of experts assembles for two days prior to the fair to exchange views on the latest fabric innovations for the winter 23/24 season. In order to ensure a more global market overview, the PERFORMANCE FORUM will curate highlights for the first time in conjunction with the US fair in Portland. Consequently, the next fair in Munich will not only feature the latest products from exhibitors at the Munich fair, but also highlights from the fair in Portland. This year’s Focus Topic in cooperation with the Vaude Academy will engage with the topic “The Sustainable Future of Nylon” and a specific hand-chosen selection of fabric materials. Furthermore, as part of the winter fair, the “sustain & innovate” conference on sustainability, organized in close cooperation with SAZsport, will take an in-depth look at the topic comprising all its aspects along with speakers, webinars and discussion rounds. The program will be broadcast live from the fair and thus accessible for all who wish to follow it online in digital form.  

Eco Award and Performance Award for Innovative Winter Fabrics 23/24
This year, in addition to a PERFORMANCE AWARD, the jury also presented an ECO PERFORMANCE AWARD. An integral part of the winter edition of PERFORMANCE DAYS is the presentation of the fabric highlights and accessory trends in the respective categories for the Winter Season 2023/24 at the PERFORMANCE FORUM. The well-known segments will be joined for the first time this winter by the Shoes & Bags category, while the renowned Lifestyle Category will be continued under its new title, “Function Meets Fashion”. The high level of innovation and quality of many of the fabrics submitted this year are particularly striking.

“The fusion of the two PERFORMANCE FORUMs of our fairs in Munich and Portland has lead to a significant increase in quality and innovation. Thanks to the new partnership, not only were we able to get new, exciting manufacturers on board, but there was also a significant increase in participation in general“, says Marco Weichert, CEO of PERFORMANCE DAYS.

Natural fabrics such as organic cotton, wool or canvas remain in demand. These are joined by significantly more plant fibers such as hemp, coconut shell, bamboo or fibers derived from pineapple or banana leaves. The additional use of castor oil, zinc or ginger supports the antibacterial effect, ensures enhanced breathability, optimum temperature management and makes the fabric soft, light and kind to the skin. The topic of recycling presents itself in various new facets and features exciting trends. The portfolio ranges from the recycling of marine waste, such as old buoys, plastic waste or fishing nets, to the recycling of waste from the automotive and computer industries, such as old car tires or computer chips. Natural dyeing methods are also gaining increasing importance, as is the recycling of materials into the textile loop.

In the Marketplace, visitors have the opportunity to view over 13,000+ products from exhibitors, including the fabric highlights of the individual categories at the PERFORMANCE FORUM. In order to be able to present the fabrics to the digital visitors as realistically as possible in terms of feel, design and structure, the PERFORMANCE FORUM has been equipped with groundbreaking 3D technology, including innovative tools such as 3D images, video animations and U3M files for download.

In addition to the PERFORMANCE AWARD WINNER, which goes to drielease/Optimer, there is also an ECO PERFORMANCE AWARD WINNER, awarded to Long Advance.

Completely new look: With the innovative Dricomfort Geo, drirelease turns to a blend of 6 % Lycra, 44 % polyester and 50 % recycled polyester. The processing of the various fibers in the knitting process, in combination with the Dricomfort GEO finishing, makes the reversible interlock fabric unique.

Unique, new pattern and knit designs are possible thanks to a special jacquard knitting process used to process the recycled polyester yarn. The material impresses with its lightness and versatility. The GEO technology also ensures optimal body temperature management. The adaptable technology provides excellent thermal regulation features through efficient heat management and enhanced moisture transport to optimize comfort and performance. Moreover, GEO boasts UV protection up to 50+.

New recycling variant: Long Advance presents LNT-21191-Z4C, a post consumer nylon that opens up a new world to recycling. The fabric, which consists of 7 % elastane and 93% recycled polyamide via Mass Balance, introduces new facets to the topic of recycling. BASF is using tire waste from now on and processes them into a new fiber. fiber. Due to the recycling, the need for synthetic fabrics are reduced to replace petroleum-based plastics with plastics made from renewable raw materials.

Photo: pixabay
24.08.2021

Air, Water, Oil: What PLA bioplastic can filter well - and what not

Air filters have been discussed so often in recent days in the fight against the pandemic. With filter material made of nonwoven fabric, they block the way back into rooms for aerosols containing viruses. But how can these devices not only protect health, but also be operated with filter material that is as environmentally friendly as possible?

Air filters have been discussed so often in recent days in the fight against the pandemic. With filter material made of nonwoven fabric, they block the way back into rooms for aerosols containing viruses. But how can these devices not only protect health, but also be operated with filter material that is as environmentally friendly as possible?

Under clearly defined conditions, the bioplastic polylactide (PLA), also known as polylactic acid, is suited for this purpose. This can be deduced from results obtained by researchers from the Zuse community in the recently completed "BioFilter" research project. The key question for this and other potential applications of biofilters is: How do the special properties of PLA affect the filter performance and durability? After all, PLA can have practical disadvantages compared to its fossil-based competitors. Its material tends to be brittle and it doesn't particularly like high temperatures beyond 60 degrees Celsius. As a biogenic material, polylactic acid is also potentially more susceptible to abrasion and organic degradation processes. This can play an even greater role in the use of filters, e.g. in sewage treatment facilities, than in air filters. Industrial customers, however, naturally want a durable, reliable product.

From monofilament to nonwoven
Against this background, the researchers studied the PLA properties in order to test nonwovens for biofilters on this basis. The German Textile Research Center North-West (German Textile Research Center North-West - DTNW) and the Saxon Textile Research Institute (STFI), where the nonwovens were produced, were involved. Granules from various commercially available manufacturers were used. However, the research did not start with nonwovens, in which the fibers are deposited close together in different layers, but with so-called monofilaments, i.e. fibers made of PLA that are comparable to threads. DTNW and STFI initially carried out tests on these monofilaments, e.g. in a climate chamber for aging and durability.

As can be seen in the picture, the monofilaments became brittle after only two weeks at higher temperatures from 70 degrees Celsius, as the DTNW authors recently reported in the Journal Applied Polymer Materials. Under normalized conditions, however, the monofilaments showed no measurable reduction in stability even after almost three years, and the PLA nonwovens were in no way inferior to their fossil-based counterparts in terms of filter performance. "In my opinion, the focus for the use of PLA as a filter material will be on applications where relatively low temperatures are present, with which PLA copes very well," says DTNW scientist Christina Schippers.

Besides temperature and humidity consider other factors
For the researchers, however, the project, which was funded by the German Federal Ministry for Economic Affairs and Energy, was not just about the suitability of polylactide for air filters, but also for other applications, such as filtering water. In addition, the research revealed that when evaluating filter media made from bio-based and biodegradable nonwovens, it is important to consider other influencing factors, such as mechanical loads caused by air currents, in addition to temperature and humidity. "The innovative core of the project was to evaluate the possibilities and application limits of PLA nonwovens as filter media with sufficient mechanical properties and long-term stability," says project leader Dr. Larisa Tsarkova. Like her colleagues at STFI, DTNW is involved in the Zuse Community's Bioeconomy Cluster, in which researchers from nonprofit institutes cooperate under the guiding principle of "Researching with Nature." "For us, the bioeconomy is a top cross-industry topic that connects numerous institutes of the Zuse Community and is lived through collaborations such as with the 'Bio-Filter'," explains the future STFI managing director Dr. Heike Illing-Günther.

Cooperation in the Bioeconomy Cluster
With the results obtained from the "Bio-Filter" project, DTNW and STFI now want to continue working in order to be able to make derivations for clearly described areas of application for PLA nonwoven filters in the future. These possible fields of application extend far beyond room air filters and thus beyond the pandemic. For example, the water-repellent property of PLA is potentially interesting for filters in large-scale kitchens for water-oil filtration or also in the industry for engine oils.

The research is also so important, because PLA is already quite well established in individual consumer-related segments - keyword: carrier bags. Traditionally, lactic acid was used to preserve food, for example in sauerkraut. Today, PLA is obtained via a multi-stage synthesis from sugar, which ferments to lactic acid and polymerizes this to PLA, as Kunststoffe.de explains. PLA is one of the best-known bioplastics, but has not always been readily available due to strong demand in recent years. The Netherlands-based company Total Corbion has announced plans to start up a PLA plant with an annual capacity of 100,000 tons in Grandpuits, France, by 2024. It would be the largest plant of its kind in Europe, with Asia leading the way so far.

Source:

Deutsche Industrieforschungsgemeinschaft Konrad Zuse e.V.