Textination Newsline

The production of new materials from fungi is an emerging research area. In a research project at the Swedish School of Textiles at the University of Borås, wet spinning of fungal cell wall material has shown promising results. In the project, fungi were grown on bread waste to produce textile fibers with potential in the medical technology field.

Sofie Svensson's project addresses, among other things, the UN's Global Goals 9, sustainable industry, innovation, and infrastructure, and Goal 12, sustainable consumption and production, as the project aimed to use sustainable methods in a resource- and cost-effective way, with less impact on people and the environment.

Sofie Svensson, who recently defended her dissertation in the field of Resource Recovery, explained:

“My research project is about developing fibres spun from filamentous fungi for textile applications. The fungi were grown on bread waste from grocery stores. Waste that would otherwise have a significant environmental impact if discarded.”

The novelty of the project lies in the method used – wet spinning of cell wall material.

“Wet spinning is a method used to spin fibres (filaments) from materials such as cellulose. In this project, cell wall material from filamentous fungi was used to produce fibres through wet spinning. The cell wall material from the fungi contains various polymers, mainly polysaccharides such as chitin, chitosan, and glucan. The challenge was to spin the material. It took some time initially before we found the right conditions”, explained Sofie Svensson.

Antibacterial properties
Filamentous fungi were cultivated in bioreactors to produce fungal biomass. Cell wall material was then isolated from the fungal biomass and used to spin a filament, which was tested for its suitability in medical applications.

“Tests of the fibers showed compatibility with skin cells and also indicated an antibacterial effect”, said Sofie Svensson, adding:

“In the method we worked with, we focused on using milder processes and chemicals. The use of hazardous and toxic chemicals is currently a challenge in the textile industry, and developing sustainable materials is important to reduce environmental impact.”

What is the significance of the results?
“New materials from fungi are an emerging research area. Hopefully, this research can contribute to the development of new sustainable materials from fungi”, explained Sofie Svensson.

Interest from the surrounding community has been significant during the project, and many have had a positive attitude toward the development of this type of material.

When will we see products made from these fibers?
“This particular method is at the lab scale and still in the research stage”, she explained.

The doctoral project was conducted within the larger research project Sustainable Fungal Textiles: A novel approach for reuse of food waste.

What is the next step in research on fungal fibers?
“Future studies could focus on optimizing the wet spinning process to achieve continuous production of fungal fibers. Additionally, testing the cultivation of fungi on other types of food waste.”

How have you experienced your time as a doctoral student in Resource Recovery?
“It has been an intense period as a doctoral student, and I have been really challenged and developed a lot.”

What is your next step?
“I will be taking parental leave for a while before taking the next step, which is yet to be decided.”

Sofie Svensson defended her dissertation on 14 June at the Swedish Centre for Resource Recovery, University of Borås.
 
Read the dissertation: Development of Filaments Using Cell Wall Material of Filamentous Fungi Grown on Bread Waste for Application in Medical Textiles

Opponent: Han Hösten, Professor, Utrecht University
Main Supervisor: Akram Zamani, Associate Professor, University of Borås
Co-Supervisors: Minna Hakkarainen, Professor, KTH; Lena Berglin, Associate Professor, University of Borå

Medical products such as ointments or syringes reach their limits when it comes to delivering medication locally – and above all in a controlled manner over a longer period of time. Empa researchers are therefore developing polymer fibers that can deliver active ingredients precisely over the long term. These "liquid core fibers" contain drugs inside and can be processed into medical textiles.

Treating a wound or an inflammation directly where it occurs has clear advantages: The active ingredient reaches its target immediately, and there are no negative side effects on uninvolved parts of the body. However, conventional local administration methods reach their limits when it comes to precisely dosing active ingredients over a longer period of time. As soon as an ointment leaves the tube or the injection fluid flows out of the syringe, it is almost impossible to control the amount of active ingredient. Edith Perret from Empa's Advanced Fibers laboratory in St. Gallen is therefore developing medical fibers with very special "inner values": The polymer fibers enclose a liquid core with therapeutic ingredients. The aim: medical products with special capabilities, e.g. surgical suture material, wound dressings and textile implants that can administer painkillers, antibiotics or insulin precisely over a longer period of time. Another aim is to achieve individual, patient-specific dosage of the drug in the sense of personalized medicine.

Biocompatible and tailor-made
A decisive factor that turns a conventional textile fiber into a medical product is the material of the fiber sheath. The team chose polycaprolactone (PCL), a biocompatible and biodegradable polymer that is already being used successfully in the medical field. The fiber sheath encloses the valuable substance, such as a painkiller or an antibacterial drug, and releases it over time. Using a unique pilot plant, the researchers produced PCL fibers with a continuous liquid core by means of melt spinning. In initial lab tests, stable and flexible liquid-core fibers were produced. What's more, the Empa team had already successfully demonstrated, together with a Swiss industrial partner, that this process not only works in the lab but also on an industrial scale.

The parameters according to which the medical fibers release an enclosed agent were first investigated using fluorescent model substances and then with various drugs. "Small molecules such as the painkiller ibuprofen move gradually through the structure of the outer sheath," says Edith Perret. Larger molecules, on the other hand, are released at the two ends of the fibers.

Precisely controllable and effective in the long term
“Thanks to a variety of parameters, the properties of the medical fibers can be precisely controlled," explains the Empa researcher. After extensive analyses using fluorescence spectroscopy, X-ray technology and electron microscopy, the researchers were able to demonstrate, for instance, the influence of the sheath thickness and crystal structure of the sheath material on the release rate of the drugs from the liquid core fibers.

Depending on the active ingredient, the manufacturing process can also be adapted: Active ingredients that are insensitive to high temperatures during melt spinning can be integrated directly into the core of the fibers in a continuous process. For temperature-sensitive drugs, on the other hand, the team was able to optimize the process so that a placeholder initially fills the liquid core, which is replaced later on by the sensitive active ingredient.

One of the advantages of liquid core fibers is the ability to release the active ingredient from a reservoir over a longer period of time. This opens up a wide range of possible applications. With diameters of 50 to 200 micrometers, the fibers are large enough to be woven or knitted into robust textiles, for example. However, the medical fibers could also be guided inside the body to deliver hormones such as insulin, says Perret. Another advantage: Fibers that have released their medication can be refilled. The range of active ingredients that can be administered easily, conveniently and precisely using liquid core fibers is large. In addition to painkillers, anti-inflammatory drugs, antibiotics and even lifestyle preparations are conceivable.

In a next step, the researchers want to equip surgical suture material with antimicrobial properties. The new process will be used to fill various liquid core materials with antibiotics in order to suture tissue during an operation in such a way that wound germs have no chance of causing an infection. Empa researcher Perret is also convinced that future collaboration with clinical partners will form the basis for further innovative clinical applications.

Aiming for clinical partnerships
Advancing a new technology? Identifying innovative applications? Empa researcher Edith Perret is looking for interested clinicians who recognize the potential of drug delivery via liquid core fibers and want to become active in this field.

 

From risottos to sauces, mushrooms have long been a staple in the kitchen. Now fungi are showing the potential to serve up more than just flavor—as a sustainable, bendy material for the fashion industry.

Researchers are using the web-like structure of the mushroom's root system—the mycelium—as an alternative to synthetic fibers for clothing and other products such as car seats.

"It's definitely a change of mindset in the manufacturing process," said Annalisa Moro, EU project leader at Italy-based Mogu, which makes interior-design products from the mycelium. "You're really collaborating with nature to grow something rather than create it, so it's kind of futuristic."

Mogu, located 50 kilometers northwest of Milan, is managing a research initiative to develop nonwoven fabrics made of mycelium fibers for the textile industry.

Called MY-FI, the project runs for four years through October 2024 and brings together companies, research institutes, industry organizations and academic institutions from across Europe.

MY-FI highlights how the EU is pushing for more sustainable production and consumption in the textile and apparel industry, which employs around 1.3 million people in Europe and has annual turnover of €167 billion.

While getting most of its textiles from abroad, the EU produces them in countries including France, Germany, Italy and Spain. Italy accounts for more than 40% of EU apparel production.

Delicate and durable
The mycelium grows from starter spawn added to crops such as cereals. The threadlike filaments of the hyphae, the vegetative part of the fungus, create a material that grows on top. It is harvested and dried, resulting in soft, silky white sheets of nonwoven fabric that are 50 to 60 square centimeters.

The delicate material is made stronger and more durable through the addition of bio-based chemicals that bind the fibers together.

Its ecological origins contrast with those of most synthetic fibers such as nylon and polyester, which derive from fossil fuels such as coal and oil.

That means production of synthetic fibers adds to greenhouse-gas emissions that are accelerating climate change. In addition, when washed, these materials shed microplastics that often end up polluting the environment including rivers, seas and oceans.

The MY-FI mycelium needs very little soil, water or chemicals, giving it greener credentials than even natural fibers such as cotton.

Dress rehearsal
For the fashion industry, the soft, water-resistant properties of the mycelium are as appealing as its environmental credentials.

Just ask Mariagrazia Sanua, sustainability and certification manager at Dyloan Bond Factory, an Italian fashion designer and manufacturer that is part of MY-FI.

The company has used the mycelium-based material—in black and brown and with a waxed finish—to produce a prototype dress, a top-and-midi-skirt combination, bags and small leather accessories.

Laser cutting and screen printing were used to evaluate the material's behavior. The challenge was to adapt to the sheets of fabric—squares of the mycelium material rather than traditional rolls of textiles like cotton, linen and polyester—as well as properties such as tensile strength and seam tightness.

"We have had to completely change the paradigm and design processes and garments based on the material," said Sanua.

The company hopes the mycelium material will be a way of offering consumers a range of products that can be alternatives to animal leather.

Leather-unbound
Meanwhile, Germany-based Volks¬wagen, the world's No. 2 car manufacturer, is looking to mycelium technologies to reduce its environmental footprint and move away from leather for vehicle interiors.

Customers increasingly want animal-free materials for interiors from seat covers and door panels to dashboards and steering wheels, so adding a sustainable substitute for leather is an exciting prospect, according to Dr. Martina Gottschling, a researcher at Volkswagen Group Innovation.

"A fast-growing biological material that can be produced animal-free and with little effort, which also does not require petroleum-based resources, is a game-changer in interior materials," she said.

The mycelium material is also lighter than leather, another positive for reducing VW's carbon footprint.

The company's involvement in MY-FI is driving project researchers at Utrecht University in the Netherlands and I-TECH Lyon in France to enhance the durability of the mycelium fabric. To move from prototype to production line, the fabric must meet quality requirements set by VW to ensure the material lasts for the life of the vehicle.

It's a challenge that Gottschling believes will be met in the coming decade.

"We already see the material as one of the high-quality materials for interior applications that will be possible in the future," she said.

When life gives you tomatoes
Mushrooms aren't the only food with the potential to spin a sustainable-yarn revolution. Tomato stems have a hidden talent too, according to Dr. Ozgur Atalay and Dr. Alper Gurarslan of Istanbul Technical University in Turkey.

Seeing tomato vines left to wither in the fields after the crop was harvested, Atalay and Gurarslan began to investigate whether the stems could be transformed into sustainable fibers.

Tests proved that the agricultural waste could indeed be turned into yarn. But Atalay and Gurarslan were determined to go a step further. They wanted to use tomato stems to create a type of yarn for garments that monitor heart beats, respiratory rates and joint movements.

The two researchers lead a project to create this kind of electrically conductive apparel using—for the first time—sustainable materials.

Called SMARTWASTE, the project runs for four years until the end of 2026 and also involves academic and research organizations from Germany, Italy, the Netherlands and Poland.

"The beauty of the project is that we are starting from waste," said Atalay. "We are taking agricultural waste and not just creating regular textiles but something much more valuable."

While cost estimates will follow later in the project when design partners work on creating actual products, he signaled that smart clothing will be a good deal more expensive than the ordinary kind.

A smart textile shirt could cost as much as €1,000, according to Atalay.

The specialized material, limited production runs and research and development needed to create wearable technologies that are durable, washable and comfortable all contribute to the price tag.

Advancements in technology should eventually lead to lower production costs and consumer prices.

Seeds of poplar success
The Turkish countryside has also inspired a second strand to the project. Turkey's abundant poplar trees and—more specifically—their white, fluffy cotton-like seeds prompted Gurarslan to investigate whether they could be a sustainable textile source.

While their fibers have been dismissed as too short to make a yarn, the seeds have three particular properties that appeal to the textile industry: a hollow, pipe-like structure that can trap heat to provide thermal qualities, an antibacterial nature and water resistance.

The network of SMARTWASTE experts has blended the seeds with recycled polyester to make a nonwoven fabric that the team intends to turn into textile products with enhanced thermal properties.

The researchers hope this is just the start of a far-reaching transformation of textiles.

"Our goal is to train the next generation of researchers and innovators in sustainable textiles," said Atalay.

Researchers have developed a method to make adaptive and eco-friendly sensors that can be directly and imperceptibly printed onto a wide range of biological surfaces, whether that’s a finger or a flower petal.

The method, developed by researchers from the University of Cambridge, takes its inspiration from spider silk, which can conform and stick to a range of surfaces. These ‘spider silks’ also incorporate bioelectronics, so that different sensing capabilities can be added to the ‘web’.

The fibres, at least 50 times smaller than a human hair, are so lightweight that the researchers printed them directly onto the fluffy seedhead of a dandelion without collapsing its structure. When printed on human skin, the fibre sensors conform to the skin and expose the sweat pores, so the wearer doesn’t detect their presence. Tests of the fibres printed onto a human finger suggest they could be used as continuous health monitors.

This low-waste and low-emission method for augmenting living structures could be used in a range of fields, from healthcare and virtual reality, to electronic textiles and environmental monitoring. The results are reported in the journal Nature Electronics.

Although human skin is remarkably sensitive, augmenting it with electronic sensors could fundamentally change how we interact with the world around us. For example, sensors printed directly onto the skin could be used for continuous health monitoring, for understanding skin sensations, or could improve the sensation of ‘reality’ in gaming or virtual reality application.

While wearable technologies with embedded sensors, such as smartwatches, are widely available, these devices can be uncomfortable, obtrusive and can inhibit the skin’s intrinsic sensations.

Last year, some of the same researchers showed that if the fibres used in smart textiles were coated with materials that can withstand stretching, they could be compatible with conventional weaving processes. Using this technique, they produced a 46-inch woven demonstrator display.

“If you want to accurately sense anything on a biological surface like skin or a leaf, the interface between the device and the surface is vital,” said Professor Yan Yan Shery Huang from Cambridge’s Department of Engineering, who led the research. “We also want bioelectronics that are completely imperceptible to the user, so they don’t in any way interfere with how the user interacts with the world, and we want them to be sustainable and low waste.”

There are multiple methods for making wearable sensors, but these all have drawbacks. Flexible electronics, for example, are normally printed on plastic films that don’t allow gas or moisture to pass through, so it would be like wrapping your skin in cling film. Other researchers have recently developed flexible electronics that are gas-permeable, like artificial skins, but these still interfere with normal sensation, and rely on energy- and waste-intensive manufacturing techniques.

3D printing is another potential route for bioelectronics since it is less wasteful than other production methods, but leads to thicker devices that can interfere with normal behaviour. Spinning electronic fibres results in devices that are imperceptible to the user, but don't have a high degree of sensitivity or sophistication, and they’re difficult to transfer onto the object in question.

Now, the Cambridge-led team has developed a new way of making high-performance bioelectronics that can be customised to a wide range of biological surfaces, from a fingertip to the fluffy seedhead of a dandelion, by printing them directly onto that surface. Their technique takes its inspiration in part from spiders, who create sophisticated and strong web structures adapted to their environment, using minimal material.

The researchers spun their bioelectronic ‘spider silk’ from PEDOT:PSS (a biocompatible conducting polymer), hyaluronic acid and polyethylene oxide. The high-performance fibres were produced from water-based solution at room temperature, which enabled the researchers to control the ‘spinnability’ of the fibres. The researchers then designed an orbital spinning approach to allow the fibres to morph to living surfaces, even down to microstructures such as fingerprints.

Tests of the bioelectronic fibres, on surfaces including human fingers and dandelion seedheads, showed that they provided high-quality sensor performance while being imperceptible to the host.

“Our spinning approach allows the bioelectronic fibres to follow the anatomy of different shapes, at both the micro and macro scale, without the need for any image recognition,” said Andy Wang, the first author of the paper. “It opens up a whole different angle in terms of how sustainable electronics and sensors can be made. It’s a much easier way to produce large area sensors.”

Most high-resolution sensors are made in an industrial cleanroom and require the use of toxic chemicals in a multi-step and energy-intensive fabrication process. The Cambridge-developed sensors can be made anywhere and use a tiny fraction of the energy that regular sensors require.

The bioelectronic fibres, which are repairable, can be simply washed away when they have reached the end of their useful lifetime, and generate less than a single milligram of waste: by comparison, a typical single load of laundry produces between 600 and 1500 milligrams of fibre waste.

“Using our simple fabrication technique, we can put sensors almost anywhere and repair them where and when they need it, without needing a big printing machine or a centralised manufacturing facility,” said Huang. “These sensors can be made on-demand, right where they’re needed, and produce minimal waste and emissions.”

The research was supported in part by the European Research Council, Wellcome, the Royal Society, and the Biotechnology and Biological Sciences Research Council (BBSRC), part of UK Research and Innovation (UKRI).

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.

Rain jackets, swimming trunks or upholstery fabrics: Textiles with water-repellent properties require chemical impregnation. Although fluorine-containing PFAS chemicals are effective, they are also harmful to human health and accumulate in the environment. Empa researchers are now developing a process with alternative substances that can be used to produce environmentally friendly water-repellent textile fibers. Initial analyses show: The "good" fibers repel water more effectively and dry faster than those of conventional products.

If swimming trunks are to retain their shape after swimming and to dry quickly, they must combine two properties: They must be elastic and must not soak up water. Such a water-repellent effect can be achieved by treating the textiles with chemicals that give the elastic garment so-called hydrophobic properties. In the 1970s, new synthetic fluorine compounds began to be used for this purpose – compounds that seemed to offer countless application possibilities, but later turned out to be highly problematic. This is because these fluorocarbon compounds, PFAS for short, accumulate in the environment and are harmful to our health (see box). Empa researchers are therefore working with Swiss textile companies to develop alternative environmentally friendly processes that can be used to give fibers a water-repellent finish. Dirk Hegemann from Empa's Advanced Fibers laboratory in St. Gallen explains the Innosuisse-funded project: "We use so-called highly cross-linked siloxanes, which create silicone-like layers and – unlike fluorine-containing PFAS – are harmless."

Empa's plasma coating facilities range from handy table-top models to room-filling devices. For the coating of textile fibers, the siloxanes are atomized and activated in a reactive gas. They thereby retain their functional properties and enclose the textile fibers in a water-repellent coating that is only 30 nanometers thin. Fibers coated this way can then be processed into water-repellent textiles of all kinds, for example garments or technical textiles such as upholstery fabrics.

The advantage over conventional wet-chemical processes: Even with complex structured textiles, the seamless distribution of the hydrophobic substances is guaranteed right into all turns of the intertwined fibers. This is crucial, because even a tiny wettable spot would be enough for water to penetrate into the depths of a pair of swimming trunks, preventing the garment from drying quickly. "We have even succeeded in permanently impregnating more demanding, elastic fibers with the new process, which was previously not possible," says Hegemann.

Great interest from industry
In initial laboratory analyses, textiles made from the new fibers with an environmentally friendly coating are already performing slightly better than conventional PFAS-coated fabrics. They absorb less water and dry faster. However, the miraculous properties of the fluorine-free coating only really come into their own after the textiles have been washed several times: While the performance of conventional PFAS coatings in stretchy textiles declines considerably after repeated wash cycles, the fluorine-free fibers retain their water-repellent properties.

Hegemann and his team are now working on scaling up the fluorine-free laboratory process into efficient and economically viable industrial processes. "The industry is very interested in finding sustainable alternatives to PFAS," says Hegemann. The Swiss textile companies Lothos KLG, beag Bäumlin & Ernst AG and AG Cilander are already on board when it comes to developing environmentally friendly fluorine-free textiles. "This is a successful collaboration that combines materials, fiber technology and plasma coating and leads to an innovative, sustainable and effective solution," says Dominik Pregger from Lothos. And Bernd Schäfer, CEO of beag, adds: "The technology is environmentally friendly and also has interesting economic potential."

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.

 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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."