Textination Newsline

Reset
96 results
Berndt Köll on the Stubai Glacier: Initial field tests showed convincing results. (c) Lenzing AG
22.11.2023

Glacier protection rethought: Nonwovens made of cellulosic fibers

Protection for snow and ice: Cellulosic LENZING™ fibers offer solution for preservation of glacier mass

In field trials on Austrian glaciers, nonwovens made of cellulosic LENZING™ fibers are being used to cover glacier mass. They are showing promising results and offer a sustainable solution for glacier protection. Nonwovens containing fossil-based synthetic fibers might cause negative environmental consequences such as microplastics on glaciers.

Protection for snow and ice: Cellulosic LENZING™ fibers offer solution for preservation of glacier mass

In field trials on Austrian glaciers, nonwovens made of cellulosic LENZING™ fibers are being used to cover glacier mass. They are showing promising results and offer a sustainable solution for glacier protection. Nonwovens containing fossil-based synthetic fibers might cause negative environmental consequences such as microplastics on glaciers.

Geotextiles are already widely used to protect snow and ice on glaciers from melting. The use of nonwovens made from cellulosic LENZING™ fibers is now achieving a sustainable turnaround. Geotextiles show great success in Austria in protecting glaciers, which are highly endangered by global warming. By covering glacier mass, its melting is slowed down and mitigated. So far, the nonwovens used to protect glaciers are usually made of fossil-based synthetic fibers. The problem with that might occur as microplastics left behind after the summer flow down into the valley and can enter the food chain through small organisms and animals.

Sustainability from production to reuse
An innovative and sustainable solution for the protection of snow and ice is now possible with the help of nonwovens made of cellulosic LENZING™ fibers. "LENZING™ fibers are derived from renewable, responsibly managed wood sources and are produced in an environmentally responsible process. Thanks to their botanic origin, they have the ability to break down, returning into nature after use" explains Berndt Köll, Business & Innovation Manager at Lenzing.

In a field trial on the Stubai Glacier, the covering of a small area with the new material containing cellulosic LENZING™ fibers was tested for the first time. The result was convincing: 4 meters of ice mass could be saved from melting. Due to its success, the project is now being expanded. In 2023 field tests started in all Austrian glaciers, which are used for tourism.

"We are pleased with the positive results and see the project as a sustainable solution for glacier protection - not only in Austria, but beyond national borders," Berndt Köll continues. There should also be a possibility to explore for recycling after the nonwovens are used: These geotextiles can be recycled and ultimately used to make yarn for textile products.

Awarded with the Swiss BIO TOP
The sustainable glacier protection and its results also convinced the jury of industry experts of the BIO TOP, a major award for wood and material innovations in Switzerland. With this award innovative projects in the field of bio-based woods and materials are promoted and supported. At the award ceremony on September 20, 2023, Geotextiles containing LENZING™ fibers were honored with the award for its solution.

Source:

Lenzing AG

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

Silk Provides the Building Blocks to Transform Modern Medicine Photo: Jenna Schad
31.10.2023

Silk Provides the Building Blocks to Transform Modern Medicine

Tufts researchers harness protein from silk to make virus-sensing gloves, surgical screws that dissolve in your body, and other next-generation biomedical materials

About a mile northwest of Tufts’ Medford/Somerville campus, on the fourth floor of a refurbished woolen factory, there is a shrine to silk. Glass vases filled with silkworm cocoons and washed silk fibers sit artfully on a shelf across from a colorful drawing of the life cycle of Bombyx mori, the domesticated silk moth. Farther in, more cocoons in wall-mounted cases border a large, close-up image of silk fibers, and displays hold dozens of prototypes made from silk, including smart fabrics, biosensors, a helmet that changes color upon impact, and potential replacements for materials like leather, plastic, and particle board.

Tufts researchers harness protein from silk to make virus-sensing gloves, surgical screws that dissolve in your body, and other next-generation biomedical materials

About a mile northwest of Tufts’ Medford/Somerville campus, on the fourth floor of a refurbished woolen factory, there is a shrine to silk. Glass vases filled with silkworm cocoons and washed silk fibers sit artfully on a shelf across from a colorful drawing of the life cycle of Bombyx mori, the domesticated silk moth. Farther in, more cocoons in wall-mounted cases border a large, close-up image of silk fibers, and displays hold dozens of prototypes made from silk, including smart fabrics, biosensors, a helmet that changes color upon impact, and potential replacements for materials like leather, plastic, and particle board.

The only things missing are the silkworms themselves, but Fiorenzo Omenetto, the director of Silklab and the Frank C. Doble Professor of Engineering at Tufts, said they will be arriving soon. The lab is building a terrarium so that visitors can view the animals.
“We’re going to have a celebration of silkworms and moths,” Omenetto said.

Silk has been cultivated and harvested for thousands of years. It is best known for the strong, shimmering fabric that can be woven from its fibers, but it also has a long history of use in medicine to dress injuries and suture wounds. At Silklab, Omenetto and his colleagues are building on silk’s legacy, proving that this ancient fiber could help create the next generation of biomedical materials.

Silk moth caterpillars, known as silkworms, extrude a single sticky strand of silk from their mouths to form cocoons, which are harvested by silk farmers to make silk thread. At its core, silk is a mixture of two proteins: fibroin, which provides the fiber’s structure, and sericin, which binds it together. With a few steps in the lab, Tufts researchers can remove the sericin and dissolve the fibers, turning a dry cocoon into a fibroin-filled liquid.

“Nature builds structural proteins that are very tough and very strong,” Omenetto said. “Your bricks are these fibroin proteins floating in water. From there, you can build whatever you want.”
Starting with shipments of dried cocoons from silk farms, Omenetto and his colleagues have been able to create gels, sponges, clear plastic-like sheets, printable inks, solids that look like amber, dippable coatings, and much more.

“Each of the materials that you make can contain all these different functions, and there’s only 24 hours in a day,” Omenetto said with a laugh. “This is why I don’t sleep.”

Biocompatible and Biodegradable
When Omenetto arrived at Tufts almost two decades ago, his research was focused on lasers and optics—silk wasn’t in the picture. But a chance conversation with David Kaplan, the Stern Family Professor of Engineering and chair of the biomedical engineering department, set him on a new path.

Kaplan, who has been working with silk since the early ’90s, was designing a silk scaffold that would help rebuild a person’s cornea, allowing cells to grow between the layers. He needed a way to ensure that the growing cells would have enough oxygen and showed the small, transparent sheet to Omenetto, who was immediately intrigued by the material. Omenetto was able to use his lab’s lasers to put tiny holes in Kaplan’s silk cornea. More collaborations quickly followed.
“We’ve worked together incessantly since then,” Kaplan said.

One of those lines of research has been finding ways to use silk to help repair and regrow bone, blood vessels, nerves, and other tissue. Silk is biocompatible, meaning it doesn’t cause harm in the body and breaks down in predictable ways. With the right preparation, silk materials can provide necessary strength and structure while the body is healing.

“You can mold and shape silk to whatever you need, and it will hold that volume while the native tissue regrows into the space and the silk material degrades,” Kaplan said. “Eventually it’s 100 percent gone, and you’re back to your normal tissue.”

Some of this work has already been approved for use by the U.S. Food and Drug Administration. A company called Sofregen, which spun out of Kaplan and Omenetto’s research, is using an injectable silk-based gel to repair damaged vocal cords, the tissues that regulate air flow and help us speak.

On their own, sturdy silk structures can keep their size, shape, and function for years before degrading. But in some instances, such as those involving surgical screws and plates intended for use in rapidly growing children, this pace would be too slow. The researchers had to find a way to speed up the time it takes for dense silk biomaterials to break down. They introduced an enzyme that our bodies produce naturally into the silk to hasten the breakdown process. The idea is that the enzyme would sit dry and inactive within the silk device until the structure is installed in a person, then the device would hydrate and activate the enzyme to digest the material more rapidly.

“We can titer in just the right amount of enzyme to make a screw go away in a week, a month, a year,” Kaplan said. “We have control over the process.”

Currently, Kaplan and his lab are working on other small, degradable medical devices that would help cut down on the number of surgeries that patients need. Ear tubes, for example, are often surgically implanted to help alleviate chronic ear infections and then need to be surgically removed. Kaplan and his colleagues have designed silk-based ear tubes that degrade on their own and can even carry antibiotics.

“As someone with a daughter who went through six surgeries on her ear, I know how helpful this could be,” Kaplan said.

Source:

Laura Castañón, Tufts University, Massachusetts USA

offshore windpark Nicholas Doherty, unsplash
17.10.2023

Pyrolysis processes promise sustainable recycling of fiber composites

Wind turbines typically operate for 20 to 30 years before they are undergoing dismantling and recycling. However, the recycling of fiber composites, especially from the thick-walled rotor blade parts, has been inadequate until now. The prevailing methods involve thermal or mechanical recycling. For a sustainable and holistic recycling process, a research consortium led by Fraunhofer IFAM is pooling their expertise to recover the fibers through pyrolysis. Subsequent surface treatment and quality testing of the recyclates allow for them to be used again in industry.

Wind turbines typically operate for 20 to 30 years before they are undergoing dismantling and recycling. However, the recycling of fiber composites, especially from the thick-walled rotor blade parts, has been inadequate until now. The prevailing methods involve thermal or mechanical recycling. For a sustainable and holistic recycling process, a research consortium led by Fraunhofer IFAM is pooling their expertise to recover the fibers through pyrolysis. Subsequent surface treatment and quality testing of the recyclates allow for them to be used again in industry.

Today, the vast majority of wind turbines can already be recycled cleanly. In the case of rotor blades, however, recycling is only just beginning. Due to the 20-year operation period and the installation rates, the blade volume for recycling will be increasing in the coming years and decades. In 2000, for example, around 6,000 wind turbines were erected in Germany, which now need to be fed into a sustainable recycling process. In 2022, about 30,000 onshore and offshore wind turbines with a capacity of 65 gigawatts were in operation in Germany alone.

As wind energy is the most important cornerstone for a climate-neutral power supply, the German government has set itself the goal of further increasing its wind energy capacity by 2030 by installing larger and more modern turbines. Rotor blades will become longer, the proportion of carbon fibers used will continue to increase - and so will the amount of waste. In addition, the existing material mix in rotor blades is expected to increase in the future and precise knowledge of the structure of the components will become even more important for recycling. This underscores the urgency of developing sustainable processing methods, especially for recycling the thick-walled fiber composites in the rotor blades.

Economic and ecological recycling solution for fiber composites on the horizon
Rotor blades of wind turbines currently up for recycling consist of more than 85 percent of glass- and carbon-fiber-reinforced thermosets (GFRP/CFRP). A large proportion of these materials is found in the flange and root area and within the fiber-reinforced straps as thick-walled laminates with a wall thicknesses of up to 150 mm. Research into high-quality material fiber recycling as continuous fibers is of particular importance, not only because of the energy required for carbon fiber production. This is where the project "Pyrolysis of thick-walled fiber composites as a key innovation in the recycling process for wind turbine rotor blades" – "RE SORT" for short – funded by the German Federal Ministry of Economics and Climate Protection comes in. The aim of the project team is the complete recycling by means of pyrolysis.

A prerequisite for high-quality recycling of fiber composites is the separation of the fibers from the mostly thermoset matrix. Although pyrolysis is a suitable process for this purpose, it has not yet gained widespread adoption. Within the project, the project partners are therefore investigating and developing pyrolysis technologies that make the recycling of thick-walled fiber composite structures economically feasible and are technically different from the recycling processes commonly used for fiber composites today. Both quasi-continuous batch and microwave pyrolysis are being considered.

Batch pyrolysis, which is being developed within the project, is a pyrolysis process in which the thermoset matrix of thick fiber composite components is slowly decomposed into oily and especially gaseous hydrocarbon compounds by external heating. In microwave pyrolysis, energy is supplied by the absorption of microwave radiation, resulting in internal rapid heat generation. Quasi-continuous batch pyrolysis as well as microwave pyrolysis allow the separation of pyrolysis gases or oils. The planned continuous microwave pyrolysis also allows for the fibers to be preserved and reused in their full length.

How the circular economy succeeds - holistic utilization of the recycled products obtained
In the next step, the surfaces of the recovered recycled fibers are prepared by means of atmospheric plasmas and wet-chemical coatings to ensure their suitability for reuse in industrial applications. Finally, strength tests can be used to decide whether the recycled fibers will be used again in the wind energy industry or, for example, in the automotive or sporting goods sectors.

The pyrolysis oils and pyrolysis gases obtained in batch and microwave pyrolysis are evaluated with respect to their usability as raw materials for polymer synthesis (pyrolysis oils) or as energy sources for energy use in combined heat and power (CHP) plants (pyrolysis gases).

Both quasi-continuous batch pyrolysis and continuous-flow microwave pyrolysis promise economical operation and a significant reduction in the environmental footprint of wind energy. Therefore, the chances for a technical implementation and utilization of the project results are very good, so that this project can make a decisive contribution to the achievement of the sustainability and climate goals of the German Federal Government.

Source:

Fraunhofer-Institut für Fertigungstechnik und Angewandte Materialforschung IFAM

A quick check with a smartphone, and the integrated spectrum analyzer recognizes the fabric the garment is made from. Photo: © Fraunhofer IPMS. A quick check with a smartphone, and the integrated spectrum analyzer recognizes the fabric the garment is made from.
10.10.2023

Checking clothing using a smartphone, AI and infrared spectroscopy

Researchers at Fraunhofer have developed an ultra-compact near-infrared spectrometer suitable for recognizing and analyzing textiles. Mixed fabrics can also be reliably identified through the combination of imaging, special AI (artificial intelligence) algorithms and spectroscopy. The technology could be used to optimize recycling old clothing, so old apparel could be sorted according to type. A highly miniaturized version of the system can even fit into a smartphone. This could lead to a host of new applications for end-users in everyday life — from checking clothes when out shopping to detecting counterfeits.

Researchers at Fraunhofer have developed an ultra-compact near-infrared spectrometer suitable for recognizing and analyzing textiles. Mixed fabrics can also be reliably identified through the combination of imaging, special AI (artificial intelligence) algorithms and spectroscopy. The technology could be used to optimize recycling old clothing, so old apparel could be sorted according to type. A highly miniaturized version of the system can even fit into a smartphone. This could lead to a host of new applications for end-users in everyday life — from checking clothes when out shopping to detecting counterfeits.

Infrared spectrometers are powerful measuring instruments when it comes to non-destructive analysis of organic materials. The Fraunhofer Institute for Photonic Microsystems IPMS in Dresden has recently developed a spectral analyzer system that recognizes and analyzes textile fabrics. The system can also reliably recognize mixed fabrics. Possible applications range from checking fabrics when out shopping to cleaning garments correctly, and even sustainable, sorted recycling. The spectrometer is so tiny, it can be integrated into a smartphone.

Researchers at Fraunhofer rely on near-infrared (NIR) spectroscopy to achieve the required reliability and accuracy when identifying textiles. The system works for wavelengths between 950 and 1900 nanometers, which is close to the visible spectrum. Advantages of near-infrared technology include being easy to use and having a wide range of applications. “We combine NIR spectroscopy with imaging and AI to achieve higher accuracy when recognizing and analyzing objects,” explains Dr. Heinrich Grüger, research scientist in the Sensoric Micromodules department at Fraunhofer IPMS.

How textile analysis works
Firstly, a conventional camera module captures an image of the garment. The AI selects a specific point from the fabric’s image data to be examined by the spectral analyzer module. Light reflected from the fabric is captured by the spectrometer module. There, it passes through an entrance slit, is transformed into parallel light beams using a collimating mirror and projected onto a grating using a scanning mirror. Depending on the angle of incidence and exit, the grating splits the light beams into different wavelengths. Light reflected from the grating is directed by the scanner mirror to a detector which captures the light as an electrical signal. An A/D converter then digitizes these signals, which are subsequently analyzed in the signal processor. The resulting spectrometric profile for the textile fabric reveals which fibers it is made from by comparing to a reference database.“ The optical resolution is 10 nanometers. This high resolution means the NIR spectrometer can also use AI to identify mixed fabrics such as items of clothing made from polyester and cotton,” says Grüger. Measuring just 10 mm × 10 mm and being 6.5 mm thick, the system is so compact it could easily be integrated into a standard smartphone.

Recycling old clothing
Grüger sees an important application for the AI-controlled spectrometer when it comes to recycling. According to the Federal Statistical Office of Germany, approximately 176,200 tons of textile and clothing waste was collected from private homes in Germany in 2021. NIR spectroscopy could improve recycling efficiency and reduce the mountain of old clothing. This would enable companies that recycle old clothing to sort it more efficiently and faster. Textiles that are still in one piece, for instance, go to the second-hand trade. Damaged textiles are sorted for recycling, and the fibers they are made from, such as linen, silk, cotton or lyocell, can be reused. Severely soiled textiles would be incinerated or processed into insulation mats, for example. Spectroscopic identifies and sorts textiles more accurately and much faster than a human can.

If NIR spectroscopy was to be integrated into a smartphone, end-users might also benefit from the Fraunhofer institute’s technology. When buying clothes, a quick check with a smartphone reveals whether that expensive silk scarf is genuinely made from silk, or whether that exclusive dress from the fashion label is not instead a counterfeit, exposed through an alternative mix of fabrics. And should the label with the cleaning instructions no longer be legible, the smartphone has a textile scanner to identify the fabric and so determine the appropriate wash cycle.

Food check and dermatology
Researchers at Fraunhofer IPMS can even envisage applications beyond the textile industry. Smartphones fitted with spectrometers might be used to provide information about the quality of groceries such as fruit and vegetables when out shopping. The technology might conceivably also be used to examine skin. A quick scan with the cell phone spectrometer could identify particularly dry or greasy patches. Perhaps applications in medical diagnostics might even be conceivable — examining patches of skin where a melanoma is suspected, for example — but this would need professional involvement too.

Source:

Fraunhofer Institute for Photonic Microsystems

Researchers made shape-changing fibers by encapsulating a balloon-like tube in a braided textile sheath. (c) : Muh Amdadul Hoque. Researchers made shape-changing fibers by encapsulating a balloon-like tube in a braided textile sheath.
27.09.2023

Artificial Muscle Fibers Could Serve as Cell Scaffolds

In two new studies, North Carolina State University researchers designed and tested a series of textile fibers that can change shape and generate force like a muscle. In the first study, the researchers focused on the materials’ influence on the artificial muscles’ strength and contraction length. The findings could help researchers tailor the fibers for different applications.

In the second, proof-of-concept study, the researchers tested their fibers as scaffolds for live cells. Their findings suggest the fibers – known as “fiber robots” – could potentially be used to develop 3D models of living, moving systems in the human body.

In two new studies, North Carolina State University researchers designed and tested a series of textile fibers that can change shape and generate force like a muscle. In the first study, the researchers focused on the materials’ influence on the artificial muscles’ strength and contraction length. The findings could help researchers tailor the fibers for different applications.

In the second, proof-of-concept study, the researchers tested their fibers as scaffolds for live cells. Their findings suggest the fibers – known as “fiber robots” – could potentially be used to develop 3D models of living, moving systems in the human body.

“We found that our fiber robot is a very suitable scaffold for the cells, and we can alter the frequency and contraction ratio to create a more suitable environment for cells,” said Muh Amdadul Hoque, graduate student in textile engineering, chemistry and science at NC State. “These were proof-of concept studies; ultimately, our goal is to see if we can study these fibers as a scaffold for stem cells, or use them to develop artificial organs in future studies.”
 
Researchers made the shape-changing fibers by encapsulating a balloon-like tube, made of a material similar to rubber, in a braided textile sheath. Inflating the interior balloon with an air pump makes the braided sheath expand, causing it to shorten.

The researchers measured the force and contraction rates of fibers made from different materials in order to understand the relationship between material and performance. They found that stronger, larger diameter yarns generated a stronger contraction force. In addition, they found that the material used to make the balloon impacted the magnitude of the contraction and generated force.
 
“We found that we could tailor the material properties to the required performance of the device,” said Xiaomeng Fang, assistant professor of textile engineering, chemistry and science at NC State. “We also found that we can make this device small enough so we can potentially use it in fabric formation and other textile applications, including in wearables and assistive devices.”
 
In a follow-up study, researchers evaluated whether they could use the shape-changing fibers as a scaffold for fibroblasts, a cell type found in connective tissues that help support other tissues or organs.

“The idea with stretching is to mimic the dynamic nature of how your body moves,” said Jessica Gluck, assistant professor of textile engineering, chemistry and science at NC State, and a study co-author.

They studied the cells’ response to the motion of the shape-changing fibers, and to different materials used in the fibers’ construction. They found the cells were able to cover and even penetrate the fiber robot’s braiding sheath. However, they saw decreases in the cells’ metabolic activity when the fiber robot’s contraction extended beyond a certain level, compared to a device made of the same material that they kept stationary.

The researchers are interested in building on the findings to see if they could use the fibers as a 3D biological model, and to investigate whether movement would impact cell differentiation. They said their model would be an advance over other existing experimental models that have been developed to show cellular response to stretching and other motion, since they can only move in two dimensions.
 
“Typically, if you want to add stretch or strain on cells, you would put them onto a plastic dish, and stretch them in one or two directions,” Gluck said. “In this study, we were able to show that in this 3D dynamic culture, the cells can survive for up to 72 hours.

“This is particularly useful for stem cells,” Gluck added. “What we could do in the future is look at what could happen at the cellular level with mechanical stress on the cells. You could look at muscle cells and see how they’re developing, or see how the mechanical action would help differentiate the cells.”

The study, “Effect of Material Properties on Fiber-Shaped Pneumatic Actuators Performance” was published in Actuators on March 18. Emily Petersen was a co-author. The study was funded by start-up funding awarded to Fang from the Department of Textile Engineering, Chemistry and Science at NC State.

The study, “Development of a Pneumatic-Driven Fiber-Shaped Robot Scaffold for Use as a Complex 3D Dynamic Culture System” was published online in Biomimetics on April 21. In addition to Gluck, Hoque and Fang, co-authors included Nasif Mahmood, Kiran M. Ali, Eelya Sefat, Yihan Huang, Emily Petersen and Shane Harrington. The study was funded by the NC State Wilson College of Textiles, the Department of Textile Engineering, Chemistry and Science and the Wilson College of Textiles Research Opportunity Seed Fund Program.

Source:

North Carolina State University, Laura Oleniacz. Übersetzung Textination

Photo unsplash.com
05.09.2023

Ananas Anam and TENCEL™ collaborate with Calvin Klein

The search for better, planet-friendly footwear material reveals a solution in one unlikely ingredient: pineapple leaves. This unique textile ingredient is the recent focus of the latest footwear design collaboration between Ananas Anam, TENCEL™ and Calvin Klein, launching Calvin Klein’s first-ever trainer featuring a knitted upper made of PIÑAYARN® blended with TENCEL™ Lyocell fibers.

Known as “The Sustainable Knit Trainer”, the trainers are a timeless closet staple, available in classic colors such as black and off-white and etched with the signature Calvin Klein logo. The PIÑAYARN® knit upper, made of 70% TENCEL™ Lyocell and 30% Anam PALF™ pineapple leaf fiber, is both from botanic origin and bio-based.

The search for better, planet-friendly footwear material reveals a solution in one unlikely ingredient: pineapple leaves. This unique textile ingredient is the recent focus of the latest footwear design collaboration between Ananas Anam, TENCEL™ and Calvin Klein, launching Calvin Klein’s first-ever trainer featuring a knitted upper made of PIÑAYARN® blended with TENCEL™ Lyocell fibers.

Known as “The Sustainable Knit Trainer”, the trainers are a timeless closet staple, available in classic colors such as black and off-white and etched with the signature Calvin Klein logo. The PIÑAYARN® knit upper, made of 70% TENCEL™ Lyocell and 30% Anam PALF™ pineapple leaf fiber, is both from botanic origin and bio-based.

As the fashion sector has begun to realize the negative environmental effects of synthetic materials, a lot of brands have turned towards plant-based materials such as PIÑAYARN®. Using a low-impact manufacturing process, PIÑAYARN® is derived from pineapple leaf waste and involves a water-free spinning process. The addition of TENCEL™ Lyocell, a fiber made from wood pulp obtained from responsibly managed forests and produced using a solvent spinning process that recycles both the solvent and water at a recovery rate of more than 99%, offers full traceability of the TENCEL™ fiber in the final blended yarn.

Melissa Braithwaite, PIÑAYARN® Product Development Manager at Ananas Anam said “The inspiration for PIÑAYARN® came from the need to provide the textile industry with an alternative to overused, often polluting, conventional fibers, such as cotton or polyester. We have an abundance of available raw material within our business, and broadening our product offering means we can valorize more waste, increasing our positive impact on the environment and society.”

Indeed, as the consumer demand for more eco-responsible textile products and footwear grows, so too has the popularity of wood-based fibers as a material alternative. Ananas Anam and TENCEL™’s collaboration with Calvin Klein has been a success in that the physical characteristics and planet-conscious benefits of both PIÑAYARN® and TENCEL™ fibers complement each other perfectly, creating a blended material that is soft and usable for various woven and knitted applications.

For material developers like Ananas Anam seeking the ideal fiber blend partner to create PIÑAYARN®, TENCEL™ Lyocellfibers are celebrated for their versatility and ability to be blended with a wide range of textiles such as hemp, linen and of course Anam PALF™ pineapple leaf fiber, to enhance the aesthetics, performance and functionality of fabrics. Additionally, beyond being used in shoe uppers, TENCEL™ Lyocell fibers can be used in every part of the shoe including the upper fabric, lining, insoles, padding, laces, zipper and sewing thread. TENCEL™ Lyocell can also be used in powder form for use in the outsoles of shoes.

“We are extremely excited about this collaboration with Ananas Anam for the launch of The Sustainable Knit Trainer by Calvin Klein, an eco-responsible and planet-friendly shoe for conscious consumers. This partnership is the perfect example of our commitment to provide education and expertise to support anyone who chooses to improve the environmental and social credentials of their products by using more responsible materials,” said Nicole Schram, Global Business Development Manager at Lenzing.

Source:

Lenzing AG

(c) Institut auf dem Rosenberg
01.09.2023

‘Blue Nomad’ - Floating Into the Future with Flax Fibres

As humanity grapples with climate change and rising sea levels, our collective imagination is more critical than ever. In light of this, bcomp presents the phenomenal work initiated by the students from Institut auf dem Rosenberg in St. Gallen and SAGA Space Architects. They’ve developed an extraordinary solution to address the environmental challenges we face: the ‘Blue Nomad’ floating habitat.

‘Blue Nomad’ is a solar-powered home designed for comfortable living on the ocean. It symbolises a future where we must explore and adapt to the changing earth’s environment. Drawing inspiration from the first Polynesian nomadic settlements and equipped with solar panels for self-sustainability, the habitat promotes a vision of living and traveling on water.

As humanity grapples with climate change and rising sea levels, our collective imagination is more critical than ever. In light of this, bcomp presents the phenomenal work initiated by the students from Institut auf dem Rosenberg in St. Gallen and SAGA Space Architects. They’ve developed an extraordinary solution to address the environmental challenges we face: the ‘Blue Nomad’ floating habitat.

‘Blue Nomad’ is a solar-powered home designed for comfortable living on the ocean. It symbolises a future where we must explore and adapt to the changing earth’s environment. Drawing inspiration from the first Polynesian nomadic settlements and equipped with solar panels for self-sustainability, the habitat promotes a vision of living and traveling on water.

bcomp is particularly excited about the project as the scaled model that was exhibited in London and Monaco prominently features their very own ampliTex™ flax fibres. A plan of building an actual prototype of the floating home is being developed by Institut auf dem Rosenberg and SAGA. It could be made from a structurally optimised weave of flax fibre, showcasing the future of organic and regenerative high-performance materials replacing conventional synthetic and fossil-based technologies. As a company, bcomp is proud to provide sustainable material solutions, and seeing their flax fibres used in such an innovative and meaningful project is both humbling and inspiring.

‘Blue Nomad’ isn’t just a solitary habitat, but a concept for a new kind of community. Imagined as modular blocks, these habitats can form larger communities and oceanic farms, allowing inhabitants to share resources while moving from one oceanic farm to the next. It’s a striking vision of a future where the lines between land and water blur, and sustainability and community building lie at the heart of human settlements.

But this vision is not just theoretical. Plans are being made for a maiden voyage of ‘Blue Nomad’ across Europe, powered purely by solar energy, promoting ocean sustainability, climatology, and future nomadism.

This project serves as a powerful reminder of what can be achieved when education, innovative design, and sustainability are united. The ‘Blue Nomad’ represents the future we envision – a future where sustainable materials play a crucial role in safeguarding our planet.

The ‘Blue Nomad’ project was exhibited at the London Design Biennale 2023 as well as the Monaco Energy Boat Challenge where it was captivating visitors and garnering significant attention from the public.    

Source:

Bcomp

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

Photo: Claude Huniade
11.07.2023

Ionofibres a new track for smart and functional textiles

Electronically conductive fibres are already in use in smart textiles, but in a recently published research article, ionically conductive fibres have proven to be of increasing interest. The so-called ionofibres achieve higher flexibility and durability and match the type of conduction our body uses. In the future, they may be used for such items as textile batteries, textile displays, and textile muscles.

The research project is being carried out by doctoral student Claude Huniade at the University of Borås and is a track within a larger project, Weafing, the goal of which is to develop novel, unprecedented garments for haptic stimulation comprising flexible and wearable textile actuators and sensors, including control electronics, as a new type of textile-based large area electronics.

WEAFING stands for Wearable Electroactive Fabrics Integrated in Garments. It started 1 January 2019 and ended 30 June 2023.

Electronically conductive fibres are already in use in smart textiles, but in a recently published research article, ionically conductive fibres have proven to be of increasing interest. The so-called ionofibres achieve higher flexibility and durability and match the type of conduction our body uses. In the future, they may be used for such items as textile batteries, textile displays, and textile muscles.

The research project is being carried out by doctoral student Claude Huniade at the University of Borås and is a track within a larger project, Weafing, the goal of which is to develop novel, unprecedented garments for haptic stimulation comprising flexible and wearable textile actuators and sensors, including control electronics, as a new type of textile-based large area electronics.

WEAFING stands for Wearable Electroactive Fabrics Integrated in Garments. It started 1 January 2019 and ended 30 June 2023.

These wearables are based on a new kind of textile muscles which yarns are coated with electromechanically active polymers and contract when a low voltage is applied. Textile muscles offer a completely novel and very different quality of haptic sensation, accessing also receptors of our tactile sensory system that do not react on vibration, but on soft pressure or stroke.

Furthermore, being textile materials, they offer a new way of designing and fabricating wearable haptics and can be seamlessly integrated into fabrics and garments. For these novel form of textile muscles, a huge range of possible applications in haptics is foreseen: for ergonomics, movement coaching in sports, or wellness, for enhancement of virtual or augmented reality applications in gaming or for training purposes, for inclusion of visually handicapped people by providing them information about their environment, for stress reduction or social communication, adaptive furniture, automotive industry and many more.

In Claude Huniade’s project, the goal is to produce conductive yarns without conductive metals.

"My research is about producing electrically conductive textile fibres, and ultimately yarns, by coating non-metals sustainably on commercial yarns. The biggest challenge is in the balance between keeping the textile properties and adding the conductive feature," said Claude Huniade.

Currenty, the uniqueness of his research leans towards the strategies employed when coating. These strategies expand to the processes and the materials used.

Uses ionic liquid
One of the tracks he investigates is about a new kind of material as textile coating, ionic liquids in combination with commercial textile fibres. Just like salt water, they conduct electricity but without water. Ionic liquid is a more stable electrolyte than salt water as nothing evaporates.

"The processable aspect is an important requirement since textile manufacturing can be harsh on textile fibres, especially when upscaling their use. The fibres can also be manufactured into woven or knitted without damaging them mechanically while retaining their conductivity. Surprisingly, they were even smoother to process into fabrics than the commercial yarns they are made from," explained Claude Huniade.

Ionofibres could be used as sensors since ionic liquids are sensitive to their environment. For example, humidity change can be sensed by the ionofibers, but also any stretch or pressure they are subjected to.

"Ionofibres could truly shine when they are combined with other materials or devices that require electrolytes. Ionofibres enable certain phenomena currently limited to happen in liquids to be feasible in air in a lightweight fashion. The applications are multiple and unique, for example for textile batteries, textile displays or textile muscles," said Claude Huniade.

Needs further research
Yet more research is needed to combine the ionofibres with other functional fibres and to produce the unique textile devices.

How do they stand out compared to common electronically conductive fibres?

"In comparison to electronically conductive fibres, ionofibers are different in how they conduct electricity. They are less conductive, but they bring other properties that electronically conductive fibers often lack. Ionofibres achieve higher flexibility and durability and match the type of conduction that our body uses. They actually match better than electronically conductive fibres with how electricity is present in nature," he concluded.

Source:

University of Borås

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

(c) Fraunhofer IBMT
10.05.2023

Using textile electrodes to stop muscle tremor

Scientists at the Fraunhofer Institute for Biomedical Engineering IBMT have been working with international partners to develop a technology platform to help relieve the symptoms of muscle tremors. Tiny biocompatible electrodes in the muscles, combined with external electrodes and controllers, form an intelligent network of sensors and actuators to detect muscle signals and provide electrical stimuli as needed. Together with exoskeletons, the technology could also help people with spinal cord injuries.

Scientists at the Fraunhofer Institute for Biomedical Engineering IBMT have been working with international partners to develop a technology platform to help relieve the symptoms of muscle tremors. Tiny biocompatible electrodes in the muscles, combined with external electrodes and controllers, form an intelligent network of sensors and actuators to detect muscle signals and provide electrical stimuli as needed. Together with exoskeletons, the technology could also help people with spinal cord injuries.

A compact controller on a belt or under a jacket, a couple of discreet textile electrodes on the arms and legs, and electrodes three centimeters long and barely a millimeter thin in the muscle are all it will take to help people with tremor disorders in the future. Whenever muscle tremors start, the system sends electrical stimuli to the muscles; these stimuli are registered by the nervous system. The nervous system then stops sending interfering signals to the muscles, which settle down again. That is the basic idea behind the technology that scientists from Fraunhofer IBMT have been working on together with project partners by developing, manufacturing, integrating and experimentally testing a set of intramuscular and external electrodes and associated controllers.

The scientists have already made some concrete achievements. “We have managed to reduce muscle tremors significantly in trials with patients,” explains Andreas Schneider-Ickert, project manager for active implants and innovation manager.

The system is part of the EU-funded joint project “EXTEND.” A total of nine project partners from five different countries are working together to develop a versatile platform of distributed neural interfaces. The technology will be able to help people with neuromuscular disorders, such as tremors, or symptoms of paralysis. Even people with spinal cord injuries could benefit from this. The technology uses external controllers to link the implanted electrodes into an intelligent network. The components communicate with each other wirelessly, exchange data, detect muscle signals and send targeted stimuli into the muscles. Implanted systems are already being used medically to provide stimulation, but the current methods require complex surgical operations that are considerably stressful for patients.

Implants for the human-machine interface
A key element of EXTEND is the implants, which are made from biocompatible platinum-iridium and silicone and are injected into the muscle through a catheter. Just three centimeters long and barely a millimeter in diameter, the tiny implant has an electrode at each end that functions as either a sensor or an actuator. External electrodes sewn into a textile ribbon supply the module with energy. This sends pulsed alternating current through the muscle tissue to the implant. “What’s innovative about this is not only the intelligent interplay between control electronics, sensors and actuators, but also the principle of modulating the alternating current to transmit data,” explains Schneider-Ickert.

Once it has been implanted and started, the sensors register the first signs of muscle tremors and pass the information on to the external components. The controller evaluates the data and sends signals through the textile electrodes to stimulate the muscle. This closes a control circuit of intelligently networked sensor and actuator components that counteracts the tremor.

The stimulus signal is not strong enough to trigger a muscle contraction directly. It is the nervous system that plays the decisive role here. This registers the stimulation in the muscle tissue and responds by stopping the commands that trigger the muscle tremor. At least that is the theory — the finer details of the relationship between tremors and signals from the nervous system are yet to be researched. “In clinical trials, however, our method is working astonishingly well. Initial trials have shown that providing the patient with stimuli for one or two hours is enough to reduce tremor symptoms for a longer period of time,” says Schneider-Ickert.

Since tremors often occur in both arms and both legs, implants can be injected and external textile electrodes placed in all the affected muscle groups. This creates a distributed sensor network. The controllers can keep track of all the implanted and external electrodes at the same time and control them in coordination with each other. All this happens in real time, with the person experiencing no delay at all.

The technology being developed in the EXTEND joint project is just as functional as conventional implant systems, but minimally invasive and therefore easier to accept and better for everyday use. The basic concept originates from a Spanish project partner. Based in this concept, the researchers at Fraunhofer IBMT designed the electrodes and implantable components and produced and integrated them in the in-house cleanroom. The scientists have 25 years of expertise in neuroprosthetics and active implants.

Exoskeletons to prevent paraplegia
For tremor patients, EXTEND brings them the hope that their symptoms can be alleviated considerably. However, the technology platform could also help people with spinal cord injuries thanks to motorized exoskeletons. This is a possible because, in cases of paralysis, the nerve fibers are often not completely cut off. They can still transmit stimuli from the brain, albeit very weakly. The sensors register the activity and transmit it to the controller, which analyzes all the signals, works out what movement the person wants to perform and activates exactly the right prostheses to support the muscles in executing the movement.

Following initial successful tests, the concepts and technologies used in EXTEND have been steadily developed, miniaturized, optimized and subjected to further implementation studies. As a result, the project has now been completed with a successful proof of concept of the miniaturized full system in humans. Fraunhofer IBMT will use the knowledge gained from EXTEND to further develop its expertise in the field of neuromuscular and neural interfaces.

Source:

Fraunhofer Institute for Biomedical Engineering IBMT

Fibroblasts (connective tissue cells) on the electrospun Renacer® membrane under the confocal microscope (red: cytoskeleton of the cells, blue: cell nuclei). (c) Fraunhofer-Institut für Silicatforschung ISC
02.05.2023

Bioresorbable membrane: depot for active substances

Fraunhofer researchers have succeeded in using the bioresorbable silica gel Renacer® to produce an electrospun membrane that is neither cytotoxic to cells nor genotoxic. This model mimics fibrous structures found in connective tissue and is therefore particularly suitable for regenerative applications, such as for improved wound healing.
 
The treatment of large as well as internal wounds is challenging and can be a very lengthy process. Researchers at the Fraunhofer Institute for Silicate Research ISC and the Fraunhofer Institute for Toxicology and Experimental Medicine ITEM have developed a bioresorbable membrane for this use. This membrane supports wound healing and biodegrades completely in the body to a natural substance.

Fraunhofer researchers have succeeded in using the bioresorbable silica gel Renacer® to produce an electrospun membrane that is neither cytotoxic to cells nor genotoxic. This model mimics fibrous structures found in connective tissue and is therefore particularly suitable for regenerative applications, such as for improved wound healing.
 
The treatment of large as well as internal wounds is challenging and can be a very lengthy process. Researchers at the Fraunhofer Institute for Silicate Research ISC and the Fraunhofer Institute for Toxicology and Experimental Medicine ITEM have developed a bioresorbable membrane for this use. This membrane supports wound healing and biodegrades completely in the body to a natural substance.

The basis for the novel membrane is a fiber fleece developed at Fraunhofer ISC. This fleece has already been approved as a medical device to support the regeneration of chronic wounds, such as the diabetic foot. During the healing process, the material dissolves completely within six to eight weeks. Using the electrospinning method, the researchers have now managed to reduce the 50-micrometer fiber diameter by a factor of more than 50, resulting in fibers with diameters of less than one micrometer (µm). This made it possible to spin a silica gel sol into an open-meshed silica gel membrane consisting of fibers with a diameter of about one µm. In some cases, the diameters achieved were as small as 100 nanometers. “These fiber systems imitate the extracellular matrix, the fiber structures found in connective tissue, in the body and are very well tolerated by human cells for tissue regeneration. They cause no foreign body reactions and no internal scarring. The innovative silica gel membrane releases only one degradation product, ortho-silicic acid. This has a regenerative effect on the tissue and promotes the closing of wounds,” explains Dr. Bastian Christ, a scientist at the Fraunhofer ISC in Würzburg. Together with his colleagues, he was in charge of the synthesis and processing of the material.
 
“While the original fiber fleece of 50 µm thick fibers is inserted into a chronic wound from the outside, the thinner fiber fleece is also suitable for internal use. Theoretically, it could be placed onto the filler material used for bone defects in the jaw to accelerate wound healing,” is how Dr. Christina Ziemann, research scientist at Fraunhofer ITEM responsible for the biological evaluation of the material, describes one of numerous possible applications. “In principle, the membrane can be glued in the body with biodegradable adhesives.

Material is neither cyto- nor genotoxic
Using a confocal microscope, a special light microscope, it was possible to show that the small-meshed membrane, which serves as a demonstrator, exhibits a barrier function. This prevents the passage of connective tissue cells for a period of at least seven days without interfering with cell proliferation. In addition, the membrane is resorbable, is not cyto- or genotoxic and thus causes no direct damage to tissue or DNA.

Fiber diameter and mesh size influence the behavior of the cells
A thin fiber diameter of 100 nanometers with thin meshes was chosen for use as an adhesion barrier to prevent postoperative adhesions and scarring. With this configuration, only nutrients could pass through the fiber fleece, but connective tissue cells could not. With a fiber diameter of one micrometer and correspondingly wider meshes, on the other hand, the cells grow into the fiber mesh, proliferate there and have a regenerating effect on the surrounding tissue. “By adjusting the material properties, such as fiber diameter and mesh size, it is possible to influence the behavior of the cells as desired,” says Christ. The equipment required for spinning the fibers is designed at Fraunhofer ISC to meet application and specific customer requirements. The shape and size of the fiber fleeces can also be adjusted to customer specifications.

Wounds only heal quickly and effectively if the wounded tissue is sufficiently supplied with nutrients. At the same time, metabolic products have to be removed. In contrast to many products on the market that allow nutrient transport only after biodegradation has started, the open-meshed Renacer® membrane promotes this transport directly after implantation, while not allowing cell passage.

Membrane with an inorganic character
There is another advantage: The Renacer® membrane dissolves completely into almost pH neutral non-toxic ortho-silicic acid, the only water-soluble form of silica. It is physiologically present in the body and has been shown to stimulate connective skin tissue formation and bone formation. Products currently available do not exhibit such bioactive properties. Many biodegradable materials dissolve into organic acids, such as lactic acid or glycolic acid. This can cause local acidification in the tissue, which then triggers inflammatory reactions of the immune system. “Our tests have shown that the dissolution product, ortho-silicic acid, is also non-toxic and completely biocompatible with cells,” says Ziemann. “The membrane decomposes into a single molecule – ortho-silicic acid.”

Fibers as a depot for active substances
Furthermore, drugs can be encapsulated into the matrix of the silica gel fibers, to be released during material resorption. “For example, antibiotics could be delivered into a wound after applying a drug-loaded Renacer® membrane to prevent the formation of bacterial colonies,” elaborates Christ. At Fraunhofer ISC, the BMBF-funded GlioGel project is testing whether the Renacer® material platform can be used as a depot for active substances in the treatment of brain tumors.

Source:

Fraunhofer-Institut für Silicatforschung ISC

(c) Fraunhofer WKI
19.04.2023

Sustainable natural-fiber reinforcement for textile-reinforced concrete components

Textile-reinforced concrete components with a sustainable natural-fiber reinforcement possess sufficient bond and tensile load-bearing behavior for the utilization in construction. This has been verified by researchers at the Fraunhofer WKI in collaboration with Biberach University of Applied Sciences and the industrial partner FABRINO. In the future, textile-reinforced components with natural-fiber reinforcement could therefore replace conventionally reinforced concrete components and improve the environmental balance in the construction industry.

Textile-reinforced concrete components with a sustainable natural-fiber reinforcement possess sufficient bond and tensile load-bearing behavior for the utilization in construction. This has been verified by researchers at the Fraunhofer WKI in collaboration with Biberach University of Applied Sciences and the industrial partner FABRINO. In the future, textile-reinforced components with natural-fiber reinforcement could therefore replace conventionally reinforced concrete components and improve the environmental balance in the construction industry.

Non-metallic reinforcements for concrete elements are currently often made from various synthetically produced fibers - for example from glass or carbon fibers. An ecological alternative to synthetic fibers is provided by flax or other natural fibers. These are widely available and are more sustainable, due, amongst other things, to their renewable raw-material basis, the advantages regarding recycling, and the lower energy requirements during production. This is where the researchers from the Fraunhofer WKI and Biberach University of Applied Sciences, in collaboration with an industrial partner, became active. Their goal was to demonstrate that reinforcements made from textile fibers are just as suitable for utilization in construction as synthetic fibers.

"At the Fraunhofer WKI, we have produced leno fabrics from flax-fiber yarn using a weaving machine. In order to enhance sustainability, we tested a treatment of the flax yarns for improving the tensile strength, durability and adhesion which is ecologically advantageous compared to petro-based treatments," explained Jana Winkelmann, Project Manager at the Fraunhofer WKI. In the coating process, a commonly used petro-based epoxy resin was successfully replaced by a partially bio-based impregnation. A large proportion (56%) of the molecular structure of the utilized epoxy resin consists of hydrocarbons of plant origin and can therefore improve the CO2 balance.

Textile reinforcements have a number of fundamental advantages. They exhibit, for example, significantly reduced corrodibility at the same or higher tensile strength than steel, with the result that the necessary nominal dimension of the concrete covering can be reduced. This often allows smaller cross-sections to be required for the same load-bearing capacity. Up to now, however, the load-bearing behavior of textile reinforcements made from natural fibers in concrete components has not been systematically investigated.

At Biberach University of Applied Sciences, researchers tested the bond and tensile load-bearing behavior as well as the uniaxial flexural load-bearing behavior of concrete components with textile reinforcement made from flax fibers. The scientists came to the conclusion that the natural-fiber-based textile-reinforced components with a bio-based impregnation are fundamentally suitable. The suitability was demonstrated by both a significant increase in the breaking load compared to non-reinforced and under-reinforced concrete components and in finely distributed crack patterns. The curves of the stress-strain diagrams could be divided into three ranges typical for reinforced expansion elements (State I - non-cracked, State IIa - initial cracking, and State IIb - final crack pattern). The delineation of the ranges becomes more pronounced as the degree of reinforcement increases.

As a whole, regionally or Europe-wide available, renewable natural fibers and a partially bio-based coating contribute towards an improvement of the CO2 footprint of the construction industry. As a result, a further opportunity is being opened up for the energy- and raw-material-intensive construction industry in terms of meeting increasingly stringent environmental and sustainability requirements. "Textile-reinforced concretes enable lighter and more slender structures and therefore offer architectural leeway. We would like to continue our research into the numerous application possibilities of natural-fiber-reinforced concretes," said Christina Haxter, a staff member at the Fraunhofer WKI.

The project, which ran from 9th December 2020 to 31st December 2022, was funded by the German Federal Environmental Foundation (DBU).   

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

In the future, one will be able to use their phone to read the clothing woven-in labels made with inexpensive photonic fibers. (c) Marcin Szczepanski/Lead Multimedia Storyteller, University of Michigan College of Engineering. In the future, one will be able to use their phone to read the clothing woven-in labels made with inexpensive photonic fibers.
15.02.2023

The new butterfly effect: A ‘game changer’ for clothing recycling?

Photonic fibers borrow from butterfly wings to enable invisible, indelible sorting labels

Less than 15% of the 92 million tons of clothing and other textiles discarded annually are recycled—in part because they are so difficult to sort. Woven-in labels made with inexpensive photonic fibers, developed by a University of Michigan-led team, could change that.
 
“It’s like a barcode that’s woven directly into the fabric of a garment,” said Max Shtein, U-M professor of materials science and engineering and corresponding author of the study in Advanced Materials Technologies. “We can customize the photonic properties of the fibers to make them visible to the naked eye, readable only under near-infrared light or any combination.”

Photonic fibers borrow from butterfly wings to enable invisible, indelible sorting labels

Less than 15% of the 92 million tons of clothing and other textiles discarded annually are recycled—in part because they are so difficult to sort. Woven-in labels made with inexpensive photonic fibers, developed by a University of Michigan-led team, could change that.
 
“It’s like a barcode that’s woven directly into the fabric of a garment,” said Max Shtein, U-M professor of materials science and engineering and corresponding author of the study in Advanced Materials Technologies. “We can customize the photonic properties of the fibers to make them visible to the naked eye, readable only under near-infrared light or any combination.”

Ordinary tags often don’t make it to the end of a garment’s life—they may be cut away or washed until illegible, and tagless information can wear off. Recycling could be more effective if a tag was woven into the fabric, invisible until it needs to be read. This is what the new fiber could do.
 
Recyclers already use near-infrared sorting systems that identify different materials according to their naturally occurring optical signatures—the PET plastic in a water bottle, for example, looks different under near-infrared light than the HDPE plastic in a milk jug. Different fabrics also have different optical signatures, but Brian Iezzi, a postdoctoral researcher in Shtein’s lab and lead author of the study, explains that those signatures are of limited use to recyclers because of the prevalence of blended fabrics.

“For a truly circular recycling system to work, it’s important to know the precise composition of a fabric—a cotton recycler doesn’t want to pay for a garment that’s made of 70% polyester,” Iezzi said. “Natural optical signatures can’t provide that level of precision, but our photonic fibers can.”

The team developed the technology by combining Iezzi and Shtein’s photonic expertise—usually applied to products like displays, solar cells and optical filters—with the advanced textile capabilities at MIT’s Lincoln Lab. The lab worked to incorporate the photonic properties into a process that would be compatible with large-scale production.
 
They accomplished the task by starting with a preform—a plastic feedstock that comprises dozens of alternating layers. In this case, they used acrylic and polycarbonate. While each individual layer is clear, the combination of two materials bends and refracts light to create optical effects that can look like color. It’s the same basic phenomenon that gives butterfly wings their shimmer.

The preform is heated and then mechanically pulled—a bit like taffy—into a hair-thin strand of fiber. While the manufacturing process method differs from the extrusion technique used to make conventional synthetic fibers like polyester, it can produce the same miles-long strands of fiber. Those strands can then be processed with the same equipment already used by textile makers.

By adjusting the mix of materials and the speed at which the preform is pulled, the researchers tuned the fiber to create the desired optical properties and ensure recyclability. While the photonic fiber is more expensive than traditional textiles, the researchers estimate that it will only result in a small increase in the cost of finished goods.

“The photonic fibers only need to make up a small percentage—as little as 1% of a finished garment,” Iezzi said. “That might increase the cost of the finished product by around 25 cents—similar to the cost of those use-and-care tags we’re all familiar with.”

Shtein says that in addition to making recycling easier, the photonic labeling could be used to tell consumers where and how goods are made, and even to verify the authenticity of brand-name products. It could be a way to add important value for customers.

“As electronic devices like cell phones become more sophisticated, they could potentially have the ability to read this kind of photonic labeling,” Shtein said. “So I could imagine a future where woven-in labels are a useful feature for consumers as well as recyclers.”

The team has applied for patent protection and is evaluating ways to move forward with the commercialization of the technology.
The research was supported by the National Science Foundation and the Under Secretary of Defense for Research and Engineering.

Source:

Gabe Cherry, College of Engineering, University of Michigan / 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

04.01.2023

Circular Economy: It could all be so simple... or not

Interview with Henning Wehland & Robert Kapferer, Circularity Germany

Interview with Henning Wehland & Robert Kapferer, Circularity Germany

I'm a very curious guy by nature. That's why I offered to help out at a well-known hot dog station in Münster (Germany) this year, to draw attention to the shortage of staff in the gastronomy. I wrote an article about it on LinkedIn, which was in turn reacted to by Ines Chucholowius.
From her profile, I could see that she is a consultant for strategic marketing and communication in the textile industry. Not entirely serious, she offered me a job in her office. Like pushing a button, the pictures in my mind set in: Textile industry, exciting! Merchandising, contacts in the industry, collaborations, and I agreed to a short chat, at the end of which we spoke on the phone and arranged to meet.
 
She told me about her website TEXTINATION.de. And we were already involved in an exciting, heated exchange about perception and truth in the textile industry. Without further ado, we left it at that and I went home with a chunk of new information about an exciting field. Our dialogue on social media continued and eventually Ines offered me the chance to feed my die-hard curiosity with the support of TEXTINATION.de. I could write a blog on the site, about people, products, service providers, producers, startups or trends that interest me, to add to my half-knowledge about the textile industry.

Textile waste into the front ... new T-shirt out the back
During this exchange and a long brainstorming session, certain terms kept tickling my attention:
Circular economy, recycling, recyclable material loops. Circular Economy, Recycling, Recyclables. Even though there are many different definitions and some even distinguishing between different aspects: the former thought from waste that flows back into production as a secondary raw material, a more modern approach avoiding waste already in production - the general consensus is really only that circular economy is a cycle in which waste is used as a source for something new.

Sounds like useful additions for all areas of the manufacturing real economy to me. Ines introduced me to Robert Kapferer: He runs a startup called Circularity Germany in Hamburg. His company, founded in 2021 and consisting of Robert and another partner, is an offshoot of the Dutch-based company Circularity B.V. Its founder Han Hamers, with a degree in child psychology and a professional background in the textile dyeing industry, had the idea five years ago for a production facility that spins new yarn exclusively from textile production waste and old textiles turning it into T-shirts, polo shirts and sweatshirts.
Whether this works, and if so, how, is what I wanted to find out, and Ines and I arranged to meet Robert for a 90-minute online conference.

Robert, originally an industrial engineer, comes from a less sustainable industry. He worked for 11 years as managing director for AVECO Material und Service GmbH, where he was responsible for the workwear of more than 50,000 employees.

At the beginning of our conversation, he emphasizes that a moment in January 2021 changed his life and from then on, he wanted to dedicate himself to the topic of circular economy with all his might. That was when he met Han Hamers, who inspired him to found Circularity Germany. His enthusiasm and passion for the subject sound credible, and he begins to describe the differences between chemical and mechanical recycling methods. In summary, the mechanical process of shredding and the subsequent spinning shortens the fibers and thus restricts their properties for further processing. The advantage lies primarily in the comparatively uncomplicated, fast and more cost-efficient process. In the chemical variant, chemical waste remains, but the processed materials are broken down again into their basic building blocks in such a way that they have almost all the same properties as a so-called virgin raw material. Circularity Germany stands for the mechanical process.

And then comes the sentence that gets all our attention: "We've advanced a spinning technology so much that it relies exclusively on waste-based raw materials."
This sentence almost doesn't stand out because Robert still talks - quite excitingly - about the fact that they are planning a production and manufacturing facility where everything from knitting yarn to relatively fine thread can be spun and then further processed into fabric. And here Ines and I ask intensively: Essential requirements for industrial production still seem to be unresolved, and necessary processes are still in the planning stage. For example, the question of whether to work with pre-consumer or post-consumer waste. Pre-consumer waste is cutting waste from the production of clothes, which corresponds to about 10% of the processed material. Post-consumer waste we know as used textiles.

As long as production still takes place in India, Circularity currently uses mainly pre-consumer waste. These come exclusively from sewing factories in the Tirupur region in the south of India. When using used textiles, which exist in large quantities in Germany (according to a study, 28-40% of all garments produced are thrown away unworn), Circularity produces blended yarns of cotton and polyester. The company does not offer pure cotton yarns.

Textiles are treated with chemicals to varying degrees - workwear in particular cannot do without them. The fact that Han Hemers is also collecting used textile stocks from the Dutch army in order to reintroduce them renewed into the consumer cycle is therefore not reassuring. Military clothing has to be finished with all kinds of additives.

Therefor I ask how he can dispel doubts in a consumer’s mind like mine, with a healthy half-knowledge of mask deals and greenwashing, that a well-intentioned vision will be followed by a dark awakening. This concern cannot yet be resolved after the conversation.

We limit ourselves to what is planned: Robert has the dream of reversing the globalized process of textile production. He wants to end the decoupling of cotton growing regions and far-flung production such as Asia with subsequent shipping of ready-made goods to Europe. In the future, existing used textiles and/or cutting wastes are to be collected on site, recycled and processed locally into new textiles.

I believe him in having this dream. However, some of my questions about sustainability remain unanswered - which is why I have my doubts about whether the idea is currently capable of performing and competing.
What are the reasons for this? For one thing, I think it's always difficult to do necessary pioneering work. Especially when listening to smart comments at the regulars' table that large companies are already working intensively on the principle of circular economy. But sometimes, apart from the term "circular economy" and a vague commitment to it, not much remains.

Circularity Germany is committed to developing a technology based exclusively on waste. The interview points out that this also includes making production more environmentally friendly and eliminating transport routes, which further reduces the burden on the environment. When all the requirements for realizing this dream have been met and a product that is competitive in terms of both quality and price can be launched on the market, it is up to the consumer to decide. Here one would have the credible argument of sustainability and a socially and environmentally fair process. Circularity would then not have to worry about PR.

It needs to be given time and, above all, attention. But perhaps the industry should get involved right here and now, and invest in startups like this and make sure that problems are cleared out of the way. Because one thing has become clear to us in this conversation:

It could all be so simple. Circular economy is achievable, but the road there is still costly and rocky. That's why we wish Robert and his team every success and, above all, perseverance. Thank you for the interview.

Short and sweet: the profile of the company in the attached factsheet for download.

 

 

A shirt that monitors breathing. Bild EMPA
28.12.2022

Wearables for healthcare: sensors to wear

Stylish sensors to wear 
With sensors that measure health parameters and can be worn on the body, we do let technology get very close to us. A collaboration between Empa and designer Laura Deschl, sponsored by the Textile and Design Alliance (TaDA) of Eastern Switzerland, shows that medical monitoring of respiratory activity, for example, can also be very stylish – as a shirt.
 
With sensors that measure health parameters and can be worn on the body, we do let technology get very close to us. A collaboration between Empa and designer Laura Deschl, sponsored by the Textile and Design Alliance (TaDA) of Eastern Switzerland, shows that medical monitoring of respiratory activity, for example, can also be very stylish – as a shirt.

Stylish sensors to wear 
With sensors that measure health parameters and can be worn on the body, we do let technology get very close to us. A collaboration between Empa and designer Laura Deschl, sponsored by the Textile and Design Alliance (TaDA) of Eastern Switzerland, shows that medical monitoring of respiratory activity, for example, can also be very stylish – as a shirt.
 
With sensors that measure health parameters and can be worn on the body, we do let technology get very close to us. A collaboration between Empa and designer Laura Deschl, sponsored by the Textile and Design Alliance (TaDA) of Eastern Switzerland, shows that medical monitoring of respiratory activity, for example, can also be very stylish – as a shirt.

The desire for a healthy lifestyle has triggered a trend towards self-tracking. Vital signs should be available at all times, for example to consistently measure training effects. At the same time, among the continuously growing group of people over 65, the desire to maintain performance into old age is stronger than ever. Preventive, health-maintaining measures must be monitored if they are to achieve the desired results. The search for measurement systems that reliably determine the corresponding health parameters is in full swing. In addition to the leisure sector, medicine needs suitable and reliable measurement systems that enable efficient and effective care for an increasing number of people in hospital and at home. After all, the increase in lifestyle diseases such as diabetes, cardiovascular problems or respiratory diseases is putting a strain on the healthcare system.

Researchers led by Simon Annaheim from Empa's Biomimetic Membranes and Textiles laboratory in St. Gallen are therefore developing sensors for monitoring health status, for example for a diagnostic belt based on flexible sensors with electrically conductive or light-conducting fibers. However, other, less technical properties can be decisive for the acceptance of continuous medical monitoring by patients. For example, the sensors must be comfortable to wear and easy to handle – and ideally also look good.

This aspect is addressed by a cooperation between the Textile and Design Alliance, or TaDA for short, in eastern Switzerland and Empa. The project showed how textile sensors can be integrated into garments. In addition to technical reliability and a high level of comfort, another focus was on the design of the garments. The interdisciplinary TaDA designer Laura Deschl worked electrically conductive fibers into a shirt that change their resistance depending on how much they are stretched. This allows the shirt to monitor how much the subjects' chest and abdomen rise and fall while they breathe, allowing conclusions to be drawn about breathing activity. Continuous monitoring of respiratory activity is of particular interest for patients during the recovery phase after surgery and for patients who are being treated with painkillers. Such a shirt could also be helpful for patients with breathing problems such as sleep apnea or asthma. Moreover, Deschl embroidered electrically conductive fibers from Empa into the shirt, which are needed to connect to the measuring device and were visually integrated into the shirt's design pattern.

The Textile and Design Alliance is a pilot program of the cultural promotion of the cantons of Appenzell Ausserrhoden, St.Gallen and Thurgau to promote cooperation between creative artists from all over the world and the textile industry. Through international calls for proposals, cultural workers from all disciplines are invited to spend three months working in the textile industry in eastern Switzerland. The TaDA network comprises 13 cooperation partners – textile companies, cultural, research and educational institutions – and thus offers the creative artists direct access to highly specialized know-how and technical means of production in order to work, research and experiment on their textile projects on site. This artistic creativity is in turn made available to the partners as innovative potential.

(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