Textination Newsline

Imagine a sweater that powers electronics to monitor your health or charge your mobile phone while running. This development faces challenges because of the lack of materials that both conduct electricity stably and are well suited for textiles. Now a research group, led by Chalmers University of Technology in Sweden, presents an ordinary silk thread, coated with a conductive plastic material, that shows promising properties for turning textiles into electricity generators.

Thermoelectric textiles convert temperature differences, for example between our bodies and the surrounding air, into an electrical potential. This technology can be of great benefit in our everyday lives and in society. Connected to a sensor, the textiles can power these devices without the need for batteries. These sensors can be used to monitor our movements or measure our heartbeat.

Since the textiles must be worn close to the body, the materials used in them must meet high demands on safety and flexibility. The silk thread that the researchers tested has a coating made of a conducting polymer. It is a plastic material with a chemical structure that makes the material electrically conductive and well adapted to textiles.

“The polymers that we use are bendable, lightweight and are easy to use in both liquid and solid form. They are also non-toxic," says Mariavittoria Craighero, who is a doctoral student at the Department of Chemistry and Chemical Engineering at Chalmers University of Technology, and first author of a recently published study.

Enhanced stability and conductivity
The method used to make the electrically conductive thread is the same as used in previous studies within the same research project.  Previously, the thread contained metals to maintain its stability in contact with air. Since then, advances have been made to manufacture the thread with only organic (carbon-based) polymers. In the current study, the researchers have developed a new type of thread with enhanced electrical conductivity and stability.

“We found the missing piece of the puzzle to make an optimal thread – a type of polymer that had recently been discovered. It has outstanding performance stability in contact with air, while at the same time having a very good ability to conduct electricity. By using polymers, we don't need any rare earth metals, which are common in electronics," says Mariavittoria Craighero.

To show how the new thread can be used in practice, the researchers manufactured two thermoelectric generators – a button sewn with the thread, and a piece of textile with sewn-in threads. When they placed the thermoelectric textiles between a hot and a cold surface, they could observe how the voltage increased on the measuring instrument. The effect depended on the temperature difference and the amount of conductive material in the textile.  As an example, the larger piece of fabric showed about 6 millivolts at a temperature difference of 30 degrees Celsius. In combination with a voltage converter, it could theoretically be used to charge portable electronics via a USB connector.  The researchers have also been able to show that the thread’s performance is maintained for at least a year. It is also machine washable.

"After seven washes, the thread retained two-thirds of its conducting properties. This is a very good result, although it needs to be improved significantly before it becomes commercially interesting," says Mariavittoria Craighero.

Can meet functions that these textiles require
The thermoelectric fabric and button cannot be produced efficiently outside the lab environment today. The material must be made and sewn in by hand, which is time-consuming. Just sewing it into the demonstrated fabric required four days of needlework. But the researchers see that the new thread has great potential and that it would be possible to develop an automated process and scale up.
 
“We have now shown that it is possible to produce conductive organic materials that can meet the functions and properties that these textiles require. This is an important step forward. There are fantastic opportunities in thermoelectric textiles and this research can be of great benefit to society," says Christian Müller, Professor at the Department of Chemistry and Chemical Engineering at Chalmers University of Technology and research leader of the study.
 
More about the study
The scientific Article Poly(benzodifurandione) Coated Silk Yarn for Thermoelectric Textiles is published in Advanced Science. Authors are Mariavittoria Craighero, Qifan Li, Zijin Zeng, Chunghyeon Choi, Youngseok Kim, Hyungsub Yoon, Tiefeng Liu, Przemysław Sowiński, Shuichi Haraguchi,  Byungil Hwang, Besira Mihiretia, Simone Fabiano and Christian Müller. The researchers are active at Chalmers University of Technology, Linköping University and Chung-Ang University in Seoul, South Korea. The research has been funded by the EU's Horizon 2020 research and innovation programme, through the Marie Skłodowska-Curie project HORATES, the Knut and Alice Wallenberg Foundation, the European Research Council (ERC), the Swedish Research Council and Linköping University.

In Germany, only 26 per cent of used textiles are recycled, mostly into cleaning rags and insulation material. The vast majority is exported to other countries or incinerated. High-quality recycling of used fibres into new textile fibres is still in its infancy. This also applies to Germany. So far, the majority of recycled used textiles have been made into cleaning cloths, fleece fabrics and insulation materials. Recycled textile fibres that replace fibres made from cotton or petroleum in new textiles are rare.
 
A variety of approaches are needed to reduce the significant environmental impacts of textile production. The priorities are to extend the useful life of textiles and to change the way we consume them. However, the recycling of used textiles that can no longer be reused must also be expanded in terms of both quantity and quality. The Oeko-Institut has therefore been commissioned by NABU to analyse the obstacles to and potential for textile recycling in Germany and In addition to clothing, textiles include home textiles such as bed linen and curtains, as well as technical textiles used, for example, in car manufacturing or in medicine.

High-quality textile recycling alone is not financially viable; rather, a legal framework is needed to promote it in the future. ‘We don't need more cleaning rags,’ says Anna Hanisch, NABU expert on circular economy, ‘Our study shows that there is great potential for higher-quality recycling so that old textiles can be turned into new textiles again. To achieve this, fibre-to-fibre recycling must be expanded. The prerequisite for this is automatic sorting by fibre composition. This is because non-reusable used textiles must be sorted before recycling. This is currently done by hand. A technical solution is what makes recycling economically viable in the first place.’
 
The mechanical recycling that has been used most of the time so far shortens the fibres, so that only a few recycled fibres are suitable for use in new textiles. For this reason, depolymerisation processes are being developed. These require more energy and chemicals, but enable higher-quality recycled fibres for new textiles. According to NABU, extended producer responsibility is necessary to finance and establish these processes. This would have to supplement the EU's mandatory separate collection of used textiles, which will come into force in 2025.

In order to reduce the environmental impact associated with textile production, various approaches are needed: the priority should be to use textiles for longer. However, recycling used textiles that can no longer be used is also part of the solution and must be expanded in terms of both quantity and quality.

Technologically, all approaches have their merits for certain mass flows in order to increase the recycling and use of recycled materials from used textiles in new products. The technologies complement each other. After sorting for reuse, recycling processes should be prioritised as follows:

1. First mechanical recycling, as it requires the least energy.
2. Then comes solvent-based processing and depolymerisation, which require a similar amount of effort.
3. Finally, there is feedstock recycling, which consumes the most resources.

Hanisch: ‘A circular economy starts with the design. For example, in order for textiles to be recycled, they should contain as few different materials as possible. To achieve this, we need ambitious ecodesign requirements for textiles. The focus here must be on durability and recyclability. Above all, however, incentives are needed to reuse recycled raw materials from old textiles. So far, this has hardly happened voluntarily.’   

Imagine a coat that captures solar energy to keep you cozy on a chilly winter walk, or a shirt that can monitor your heart rate and temperature. Picture clothing athletes can wear to track their performance without the need for bulky battery packs.

University of Waterloo researchers have developed a smart fabric with these remarkable capabilities. The fabric has the potential for energy harvesting, health monitoring and movement tracking applications.

The new fabric can convert body heat and solar energy into electricity, potentially enabling continuous operation with no need for an external power source. Different sensors monitoring temperature, stress and more can be integrated into the material.

It can detect temperature changes and a range of other sensors to monitor pressure, chemical composition and more. One promising application is smart face masks that can track breath temperature and rate and detect chemicals in breath to help identify viruses, lung cancer and other conditions.

“We have developed a fabric material with multifunctional sensing capabilities and self-powering potential,” said Yuning Li, a professor in the Department of Chemical Engineering. “This innovation brings us closer to practical applications for smart fabrics.”

Unlike current wearable devices that often depend on external power sources or frequent recharging, this breakthrough research has created a novel fabric which is more stable, durable, and cost-effective than other fabrics on the market.

This research, conducted in collaboration with Professor Chaoxia Wang and PhD student Jun Peng from the College of Textile Science and Engineering at Jiangnan University, showcases the potential of integrating advanced materials such as MXene and conductive polymers with cutting-edge textile technologies to advance smart fabrics for wearable technology.

Li, director of Waterloo’s Printable Electronic Materials Lab, highlighted the significance of this advancement, which is the latest in the university’s suite of technologies disrupting health boundaries.

“AI technology is evolving rapidly, offering sophisticated signal analysis for health monitoring, food and pharmaceutical storage, environmental monitoring, and more. However, this progress relies on extensive data collection, which conventional sensors, often bulky, heavy, and costly, cannot meet,” Li said. “Printed sensors, including those embedded in smart fabrics, are ideal for continuous data collection and monitoring. This new smart fabric is a step forward in making these applications practical.”

The next phase of research will focus on further enhancing the fabric’s performance and integrating it with electronic components in collaboration with electrical and computer engineers. Future developments may include a smartphone app to track and transmit data from the fabric to healthcare professionals, enabling real-time, non-invasive health monitoring and everyday use.

The study is published in the Journal of Materials Science & Technology.

Researchers engineered a hair-thin fabric to create a lightweight, compact, and efficient mechanism to reduce noise transmission in a large room.

We are living in a very noisy world. From the hum of traffic outside your window to the next-door neighbor’s blaring TV to sounds from a co-worker’s cubicle, unwanted noise remains a resounding problem.

To cut through the din, an interdisciplinary collaboration of researchers from MIT and elsewhere developed a sound-suppressing silk fabric that could be used to create quiet spaces.

The fabric, which is barely thicker than a human hair, contains a special fiber that vibrates when a voltage is applied to it. The researchers leveraged those vibrations to suppress sound in two different ways.

In one, the vibrating fabric generates sound waves that interfere with an unwanted noise to cancel it out, similar to noise-canceling headphones, which work well in a small space like your ears but do not work in large enclosures like rooms or planes.

In the other, more surprising technique, the fabric is held still to suppress vibrations that are key to the transmission of sound. This prevents noise from being transmitted through the fabric and quiets the volume beyond. This second approach allows for noise reduction in much larger spaces like rooms or cars.

By using common materials like silk, canvas, and muslin, the researchers created noise-suppressing fabrics which would be practical to implement in real-world spaces. For instance, one could use such a fabric to make dividers in open workspaces or thin fabric walls that prevent sound from getting through.

The fabric can suppress sound by generating sound waves that interfere with an unwanted noise to cancel it out (as seen in figure C) or by being held still to suppress vibrations that are key to the transmission of sound (as seen in figure D).

“Noise is a lot easier to create than quiet. In fact, to keep noise out we dedicate a lot of space to thick walls. [First author] Grace’s work provides a new mechanism for creating quiet spaces with a thin sheet of fabric,” says Yoel Fink, a professor in the departments of Materials Science and Engineering and Electrical Engineering and Computer Science, a Research Laboratory of Electronics principal investigator, and senior author of a paper on the fabric.

Silky silence
The sound-suppressing silk builds off the group’s prior work to create fabric microphones.

In that research, they sewed a single strand of piezoelectric fiber into fabric. Piezoelectric materials produce an electrical signal when squeezed or bent. When a nearby noise causes the fabric to vibrate, the piezoelectric fiber converts those vibrations into an electrical signal, which can capture the sound.

In the new work, the researchers flipped that idea to create a fabric loudspeaker that can be used to cancel out soundwaves.

“While we can use fabric to create sound, there is already so much noise in our world. We thought creating silence could be even more valuable,” Yang says.

Applying an electrical signal to the piezoelectric fiber causes it to vibrate, which generates sound. The researchers demonstrated this by playing Bach’s “Air” using a 130-micrometer sheet of silk mounted on a circular frame.

To enable direct sound suppression, the researchers use a silk fabric loudspeaker to emit sound waves that destructively interfere with unwanted sound waves. They control the vibrations of the piezoelectric fiber so that sound waves emitted by the fabric are opposite of unwanted sound waves that strike the fabric, which can cancel out the noise.

However, this technique is only effective over a small area. So, the researchers built off this idea to develop a technique that uses fabric vibrations to suppress sound in much larger areas, like a bedroom.

Let’s say your next-door neighbors are playing foosball in the middle of the night. You hear noise in your bedroom because the sound in their apartment causes your shared wall to vibrate, which forms sound waves on your side.

To suppress that sound, the researchers could place the silk fabric onto your side of the shared wall, controlling the vibrations in the fiber to force the fabric to remain still. This vibration-mediated suppression prevents sound from being transmitted through the fabric.

“If we can control those vibrations and stop them from happening, we can stop the noise that is generated, as well,” Yang says.

A mirror for sound
Surprisingly, the researchers found that holding the fabric still causes sound to be reflected by the fabric, resulting in a thin piece of silk that reflects sound like a mirror does with light.

Their experiments also revealed that both the mechanical properties of a fabric and the size of its pores affect the efficiency of sound generation. While silk and muslin have similar mechanical properties, the smaller pore sizes of silk make it a better fabric loudspeaker.

But the effective pore size also depends on the frequency of sound waves. If the frequency is low enough, even a fabric with relatively large pores could function effectively, Yang says.

When they tested the silk fabric in direct suppression mode, the researchers found that it could significantly reduce the volume of sounds up to 65 decibels (about as loud as enthusiastic human conversation). In vibration-mediated suppression mode, the fabric could reduce sound transmission up to 75 percent.

These results were only possible due to a robust group of collaborators, Fink says. Graduate students at the Rhode Island School of Design helped the researchers understand the details of constructing fabrics; scientists at the University of Wisconsin at Madison conducted simulations; researchers at Case Western Reserve University characterized materials; and chemical engineers in the Smith Group at MIT used their expertise in gas membrane separation to measure airflow through the fabric.

Moving forward, the researchers want to explore the use of their fabric to block sound of multiple frequencies. This would likely require complex signal processing and additional electronics.

In addition, they want to further study the architecture of the fabric to see how changing things like the number of piezoelectric fibers, the direction in which they are sewn, or the applied voltages could improve performance.

“There are a lot of knobs we can turn to make this sound-suppressing fabric really effective. We want to get people thinking about controlling structural vibrations to suppress sound. This is just the beginning,” says Yang.

This work is funded, in part, by the National Science Foundation (NSF), the Army Research Office (ARO), the Defense Threat Reduction Agency (DTRA), and the Wisconsin Alumni Research Foundation.

Introducing the fashion of the future: a T-shirt you can wear a few times, then, when you get bored with it, dissolve and recycle to make a new shirt.

Researchers at the ATLAS Institute at the CU Boulder are now one step closer to that goal. In a new study, the team of engineers and designers developed a DIY machine that spins textile fibers made of materials like sustainably sourced gelatin. The group’s “biofibers” feel a bit like flax fiber and dissolve in hot water in minutes to an hour.

The team, led by Eldy Lázaro Vásquez, a doctoral student in the ATLAS Institute, presented its findings in May at the CHI Conference on Human Factors in Computing Systems in Honolulu.

“When you don’t want these textiles anymore, you can dissolve them and recycle the gelatin to make more fibers,” said Michael Rivera, a co-author of the new research and assistant professor in the ATLAS Institute and Department of Computer Science.

The study tackles a growing problem around the world: In 2018 alone, people in the United States added more than 11 million tons of textiles to landfills, according to the Environmental Protection Agency—nearly 8% of all municipal solid waste produced that year.

The researchers envision a different path for fashion.

Their machine is small enough to fit on a desk and cost just $560 to build. Lázaro Vásquez hopes the device will help designers around the world experiment with making their own biofibers.

“You could customize fibers with the strength and elasticity you want, the color you want,” she said. “With this kind of prototyping machine, anyone can make fibers. You don’t need the big machines that are only in university chemistry departments.”

Spinning threads
The study arrives as fashionistas, roboticists and more are embracing a trend known as “smart textiles.” Levi’s Trucker Jacket with Jacquard by Google, for example, looks like a denim coat but includes sensors that can connect to your smartphone.

But such clothing of the future comes with a downside, Rivera said:

“That jacket isn't really recyclable. It's difficult to separate the denim from the copper yarns and the electronics.”

To imagine a new way of making clothes, the team started with gelatin. This springy protein is common in the bones of many animals, including pigs and cows. Every year, meat producers throw away large volumes of gelatin that doesn’t meet requirements for cosmetics or food products like Jell-O. (Lázaro Vásquez bought her own gelatin, which comes as a powder, from a local butcher shop.)

She and her colleagues decided to turn that waste into wearable treasure.

The group’s machine uses a plastic syringe to heat up and squeeze out droplets of a liquid gelatin mixture. Two sets of rollers in the machine then tug on the gelatin, stretching it out into long, skinny fibers—not unlike a spider spinning a web from silk. In the process, the fibers also pass through liquid baths where the researchers can introduce bio-based dyes or other additives to the material. Adding a little bit of genipin, an extract from fruit, for example, makes the fibers stronger.

Other co-authors of the research included Mirela Alistar and Laura Devendorf, both assistant professors in ATLAS.

Dissolving duds
Lázaro Vásquez said designers may be able to do anything they can imagine with these sorts of textiles.

As a proof of concept, the researchers made small textile sensors out of gelatin fibers and cotton and conductive yarns, similar to the makeup of a Jacquard jacket. The team then submerged these patches in warm water. The gelatin dissolved, releasing the yarns for easy recycling and reuse.

Designers could tweak the chemistry of the fibers to make them a little more resilient, Lázaro Vásquez said—you wouldn’t want your jacket to disappear in the rain. They could also play around with spinning similar fibers from other natural ingredients. Those materials include chitin, a component of crab shells, or agar-agar, which comes from algae.

“We’re trying to think about the whole lifecycle of our textiles,” Lázaro Vásquez said. “That begins with where the material is coming from. Can we get it from something that normally goes to waste?”

A new study from NC State University combines three-dimensional embroidery techniques with machine learning to create a fabric-based sensor that can control electronic devices through touch.

As the field of wearable electronics gains more interest and new functions are added to clothing, an embroidery-based sensor or “button” capable of controlling those functions becomes increasingly important. Integrated into the fabric of a piece of clothing, the sensor can activate and control electronic devices like mobile apps entirely by touch.  

The device is made up of two parts; the embroidered pressure sensor itself and a microchip which processes and distributes the data collected by that sensor. The sensor is triboelectric, which means that it powers itself using the electric charge generated from the friction between its multiple layers. It is made from yarns consisting of two triboelectric materials, one with a positive electric charge and the other with a negative charge, which were integrated into conventional textile fabrics using embroidery machines.

Rong Yin, corresponding author of the study, said that the three-dimensional structure of the sensor was important to get right.

“Because the pressure sensor is triboelectric, it needed to have two layers with a gap in between them. That gap was one of the difficult parts in the process, because we are using embroidery which is usually two-dimensional. It’s a technique for decorating fabric,” he said. “It’s challenging to make a three-dimensional structure that way. By using a spacer, we were able to control the gap between the two layers which lets us control the sensor’s output.”

Data from the pressure sensor is then sent to the microchip, which is responsible for turning that raw input into specific instructions for any connected devices. Machine learning algorithms are key to making sure this runs smoothly, Yin said. The device needs to be able to tell the difference between gestures assigned to different functions, as well to disregard any unintentional inputs that might come from the cloth’s normal movement.

“Sometimes the data that the sensor acquires is not very accurate, and this can happen for all kinds of reasons,” Yin said. “Sometimes the data will be affected by environmental factors like temperature or humidity, or the sensor touches something by mistake. By using machine learning, we can train the device to recognize those kinds of things.

“Machine learning also allows this very small device to achieve many different tasks, because it can recognize different kinds of inputs.”

The researchers demonstrated this input recognition by developing a simple music playing mobile app which connected to the sensor via Bluetooth. They designed six functions for the app: play/pause, next song, last song, volume up, volume down and mute, each controlled by a different gesture on the sensor. Researchers were able to use the device for several other functions, including setting and inputting passwords and controlling video games.

The idea is still in its early stages, Yin said, as existing embroidery technology is not capable of easily handling the types of materials used in the creation of the sensor. Still, the new sensor represents another piece of the developing wearable electronics puzzle, which is sure to continue picking up interest in the near future.

The paper, “A clickable embroidered triboelectric sensor for smart fabric,” is published in Device.

In a world first for the fashion industry, in October 2020 twelve pioneering players came together to break new ground by demonstrating a circular model for commercial garment production. Over more than three years, textile waste was collected and sorted, and regenerated into a new, man-made cellulosic fiber that looks and feels like cotton – a “new cotton” – using Infinited Fiber Company’s textile fiber regeneration technology.
 
The pioneering New Cotton Project launched in October 2020 with the aim of demonstrating a circular value chain for commercial garment production. Through-out the project the consortium worked to collect and sort end-of-life textiles, which using pioneering Infinited Fiber technology could be regenerated into a new man-made cellulosic fibre called Infinna™ which looks and feels just like virgin cotton. The fibres were then spun into yarns and manufactured into different types of fabric which were designed, produced, and sold by adidas and H&M, making the adidas by Stella McCartney tracksuit and a H&M printed jacket and jeans the first to be produced through a collaborative circular consortium of this scale, demonstrating a more innovative and circular way of working for the fashion industry.
 
As the project completes in March 2024, the consortium highlights eight key factors they have identified as fundamental to the successful scaling of fibre-to-fibre recycling.

The wide scale adoption of circular value chains is critical to success
Textile circularity requires new forms of collaboration and open knowledge exchange among different actors in circular ecosystems. These ecosystems must involve actors beyond traditional supply chains and previously disconnected industries and sectors, such as the textile and fashion, waste collection and sorting and recycling industries, as well as digital technology, research organisations and policymakers. For the ecosystem to function effectively, different actors need to be involved in aligning priorities, goals and working methods, and to learn about the others’ needs, requirements and techno-economic possibilities. From a broader perspective, there is also a need for a more fundamental shift in mindsets and business models concerning a systemic transition toward circularity, such as moving away from the linear fast fashion business models. As well as sharing knowledge openly within such ecosystems, it also is important to openly disseminate lessons learnt and insights in order to help and inspire other actors in the industry to transition to the Circular Economy.

Circularity starts with the design process
When creating new styles, it is important to keep an end-of-life scenario in mind right from the beginning. As this will dictate what embellishments, prints, accessories can be used. If designers make it as easy as possible for the recycling process, it has the bigger chance to actually be feedstock again. In addition to this, it is important to develop business models that enable products to be used as long as possible, including repair, rental, resale, and sharing services.

Building and scaling sorting and recycling infrastructure is critical
In order to scale up circular garment production, there is a need for technological innovation and infrastructure development in end-of-use textiles collection, sorting, and the mechanical pre-processing of feedstock. Currently, much of the textiles sorting is done manually, and the available optical sorting and identification technologies are not able to identify garment layers, complex fibre blends, or which causes deviations in feedstock quality for fibre-to-fibre recycling. Feedstock preprocessing is a critical step in textile-to-textile recycling, but it is not well understood outside of the actors who actually implement it. This requires collaboration across the value chain, and it takes in-depth knowledge and skill to do it well. This is an area that needs more attention and stronger economic incentives as textile-to-textile recycling scales up.

Improving quality and availability of data is essential
There is still a significant lack of available data to support the shift towards a circular textiles industry. This is slowing down development of system level solutions and economic incentives for textile circulation. For example, quantities of textiles put on the market are often used as a proxy for quantities of post-consumer textiles, but available data is at least two years old and often incomplete. There can also be different textile waste figures at a national level that do not align, due to different methodologies or data years. This is seen in the Dutch 2018 Mass Balance study reports and 2020 Circular Textile Policy Monitoring Report, where there is a 20% difference between put on market figures and measured quantities of post-consumer textiles collected separately and present in mixed residual waste. With the exception of a few good studies such as Sorting for Circularity Europe and ReFashion’s latest characterization study, there is almost no reliable information about fibre composition in the post-consumer textile stream either. Textile-to-textile recyclers would benefit from better availability of more reliable data. Policy monitoring for Extended Producer Responsibility schemes should focus on standardising reporting requirements across Europe from post-consumer textile collection through their ultimate end point and incentivize digitization so that reporting can be automated, and high-quality textile data becomes available in near-real time.

The need for continuous research and development across the entire value chain
Overall, the New Cotton Project’s findings suggest that fabrics incorporating Infinna™ fibre offer a more sustainable alternative to traditional cotton and viscose fabrics, while maintaining similar performance and aesthetic qualities. This could have significant implications for the textile industry in terms of sustainability and lower impact production practices. However, the project also demonstrated that the scaling of fibre-to-fibre recycling will continue to require ongoing research and development across the entire value chain. For example, the need for research and development around sorting systems is crucial. Within the chemical recycling process, it is also important to ensure the high recovery rate and circulation of chemicals used to limit the environmental impact of the process. The manufacturing processes also highlighted the benefit for ongoing innovation in the processing method, requiring technologies and brands to work closely with manufacturers to support further development in the field.

Thinking beyond lower impact fibres
The New Cotton Project value chain third party verified LCA reveals that the cellulose carbamate fibre, and in particular when produced with a renewable electricity source, shows potential to lower environmental impacts compared to conventional cotton and viscose. Although, it's important to note that this comparison was made using average global datasets from Ecoinvent for cotton and viscose fibres, and there are variations in the environmental performance of primary fibres available on the market. However, the analysis also highlights the importance of the rest of the supply chain to reduce environmental impact. The findings show that even if we reduce the environmental impacts by using recycled fibres, there is still work to do in other life cycle stages. For example; garment quality and using the garment during their full life span are crucial for mitigating the environmental impacts per garment use.
          
Citizen engagement
The EU has identified culture as one of the key barriers to the adoption of the circular economy within Europe. An adidas quantitative consumer survey conducted across three key markets during the project revealed that there is still confusion around circularity in textiles, which has highlighted the importance of effective citizen communication and engagement activities.

Cohesive legislation
Legislation is a powerful tool for driving the adoption of more sustainable and circular practices in the textiles industry. With several pieces of incoming legislation within the EU alone, the need for a cohesive and harmonised approach is essential to the successful implementation of policy within the textiles industry. Considering the link between different pieces of legislation such as Extended Producer Responsibility and the Ecodesign for Sustainable Products Regulation, along with their corresponding timeline for implementation will support stakeholders from across the value chain to prepare effectively for adoption of these new regulations.

The high, and continuously growing demand for recycled materials implies that all possible end-of-use textiles must be collected and sorted. Both mechanical and chemical recycling solutions are needed to meet the demand. We should also implement effectively both paths; closed-loop (fibre-to-fibre) and open -loop recycling (fibre to other sectors). There is a critical need to reconsider the export of low-quality reusable textiles outside the EU. It would be more advantageous to reuse them in Europe, or if they are at the end of their lifetime recycle these textiles within the European internal market rather than exporting them to countries where demand is often unverified and waste management inadequate.

Overall, the learnings spotlight the need for a holistic approach and a fundamental mindset shift in ways of working for the textiles industry. Deeper collaboration and knowledge exchange is central to developing effective circular value chains, helping to support the scaling of innovative recycling technologies and increase availability of recycled fibres on the market. The further development and scaling of collecting and sorting, along with the need to address substantial gaps in the availability of quality textile flow data should be urgently prioritised. The New Cotton Project has also demonstrated the potential of recycled fibres such as Infinna™ to offer a more sustainable option to some other traditional fibres, but at the same time highlights the importance of addressing the whole value chain holistically to make greater gains in lowering environmental impact. Ongoing research and development across the entire value chain is also essential to ensure we can deliver recycled fabrics at scale in the future.

The New Cotton Project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 101000559.

 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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