Textination Newsline

MIT researchers developed a fiber computer and networked several of them into a garment that learns to identify physical activities.

What if the clothes you wear could care for your health?
MIT researchers have developed an autonomous programmable computer in the form of an elastic fiber, which could monitor health conditions and physical activity, alerting the wearer to potential health risks in real-time. Clothing containing the fiber computer was comfortable and machine washable, and the fibers were nearly imperceptible to the wearer, the researchers report.

Unlike on-body monitoring systems known as “wearables,” which are located at a single point like the chest, wrist, or finger, fabrics and apparel have an advantage of being in contact with large areas of the body close to vital organs. As such, they present a unique opportunity to measure and understand human physiology and health.
The fiber computer contains a series of microdevices, including sensors, a microcontroller, digital memory, bluetooth modules, optical communications, and a battery, making up all the necessary components of a computer in a single elastic fiber.

The researchers added four fiber computers to a top and a pair of leggings, with the fibers running along each limb. In their experiments, each independently programmable fiber computer operated a machine-learning model that was trained to autonomously recognize exercises performed by the wearer, resulting in an average accuracy of about 70 percent.

Surprisingly, once the researchers allowed the individual fiber computers to communicate among themselves, their collective accuracy increased to nearly 95 percent.
“Our bodies broadcast gigabytes of data through the skin every second in the form of heat, sound, biochemicals, electrical potentials, and light, all of which carry information about our activities, emotions, and health. Unfortunately, most — if not all — of it gets absorbed and then lost in the clothes we wear. Wouldn’t it be great if we could teach clothes to capture, analyze, store, and communicate this important information in the form of valuable health and activity insights?” says Yoel Fink, a professor of materials science and engineering at MIT, a principal investigator in the Research Laboratory of Electronics (RLE) and the Institute for Soldier Nanotechnologies (ISN), and senior author of a paper on the research, which has been published in Nature.

The use of the fiber computer to understand health conditions and help prevent injury will soon undergo a significant real-world test as well. U.S. Army and Navy service members will be conducting a monthlong winter research mission to the Arctic, covering 1,000 kilometers in average temperatures of -40 degrees Fahrenheit. Dozens of base layer merino mesh shirts with fiber computers will be providing real-time information on the health and activity of the individuals participating on this mission, called Musk Ox II.

“In the not-too-distant future, fiber computers will allow us to run apps and get valuable health care and safety services from simple everyday apparel. We are excited to see glimpses of this future in the upcoming Arctic mission through our partners in the U.S. Army, Navy, and DARPA. Helping to keep our service members safe in the harshest environments is a honor and privilege,” Fink says.

He is joined on the paper by co-lead authors Nikhil Gupta, an MIT materials science and engineering graduate student; Henry Cheung MEng ’23; and Syamantak Payra ’22, currently a graduate student at Stanford University; John Joannopoulos, the Francis Wright Professor of Physics at MIT and director of the Institute for Soldier Nanotechnologies; as well as others at MIT, Rhode Island School of Design, and Brown University.

Fiber focus
The fiber computer builds on more than a decade of work in the Fibers@MIT lab at the RLE and was supported primarily by ISN. In previous papers, the researchers demonstrated methods for incorporating semiconductor devices, optical diodes, memory units, elastic electrical contacts, and sensors into fibers that could be formed into fabrics and garments.

“But we hit a wall in terms of the complexity of the devices we could incorporate into the fiber because of how we were making it. We had to rethink the whole process. At the same time, we wanted to make it elastic and flexible so it would match the properties of traditional fabrics,” says Gupta.
 
One of the challenges that researchers surmounted is the geometric mismatch between a cylindrical fiber and a planar chip. Connecting wires to small, conductive areas, known as pads, on the outside of each planar microdevice proved to be difficult and prone to failure because complex microdevices have many pads, making it increasingly difficult to find room to attach each wire reliably.

In this new design, the researchers map the 2D pad alignment of each microdevice to a 3D layout using a flexible circuit board called an interposer, which they wrapped into a cylinder. They call this the “maki” design. Then, they attach four separate wires to the sides of the “maki” roll and connected all the components together.
“This advance was crucial for us in terms of being able to incorporate higher functionality computing elements, like the microcontroller and Bluetooth sensor, into the fiber,” says Gupta.

This versatile folding technique could be used with a variety of microelectronic devices, enabling them to incorporate additional functionality.

In addition, the researchers fabricated the new fiber computer using a type of thermoplastic elastomer that is several times more flexible than the thermoplastics they used previously. This material enabled them to form a machine-washable, elastic fiber that can stretch more than 60 percent without failure.

They fabricate the fiber computer using a thermal draw process that the Fibers@MIT group pioneered in the early 2000s. The process involves creating a macroscopic version of the fiber computer, called a preform, that contains each connected microdevice.

This preform is hung in a furnace, melted, and pulled down to form a fiber, which also contains embedded lithium-ion batteries so it can power itself.
“A former group member, Juliette Marion, figured out how to create elastic conductors, so even when you stretch the fiber, the conductors don’t break. We can maintain functionality while stretching it, which is crucial for processes like knitting, but also for clothes in general,” Gupta says.

Bring out the vote
Once the fiber computer is fabricated, the researchers use a braiding technique to cover the fiber with traditional yarns, such as polyester, merino wool, nylon, and even silk.

In addition to gathering data on the human body using sensors, each fiber computer incorporates LEDs and light sensors that enable multiple fibers in one garment to communicate, creating a textile network that can perform computation.

Each fiber computer also includes a Bluetooth communication system to send data wirelessly to a device like a smartphone, which can be read by a user.

The researchers leveraged these communication systems to create a textile network by sewing four fiber computers into a garment, one in each sleeve. Each fiber ran an independent neural network that was trained to identify exercises like squats, planks, arm circles, and lunges.

“What we found is that the ability of a fiber computer to identify human activity was only about 70 percent accurate when located on a single limb, the arms or legs.
However, when we allowed the fibers sitting on all four limbs to ‘vote,’ they collectively reached nearly 95 percent accuracy, demonstrating the importance of residing on multiple body areas and forming a network between autonomous fiber computers that does not need wires and interconnects,” Fink says.

Moving forward, the researchers want to use the interposer technique to incorporate additional microdevices.

Arctic insights
In February, a multinational team equipped with computing fabrics will travel for 30 days and 1,000 kilometers in the Arctic. The fabrics will help keep the team safe, and set the stage for future physiological “digital twinning” models.

“As a leader with more than a decade of Arctic operational experience, one of my main concerns is how to keep my team safe from debilitating cold weather injuries — a primary threat to operators in the extreme cold,” says U.S. Army Major Mathew Hefner, the commander of Musk Ox II. “Conventional systems just don’t provide me with a complete picture. We will be wearing the base layer computing fabrics on us 24/7 to help us better understand the body’s response to extreme cold and ultimately predict and prevent injury.”
 
Karl Friedl, U.S. Army Research Institute of Environmental Medicine senior research scientist of performance physiology, noted that the MIT programmable computing fabric technology may become a “gamechanger for everyday lives.”

“Imagine near-term fiber computers in fabrics and apparel that sense and respond to the environment and to the physiological status of the individual, increasing comfort and performance, providing real-time health monitoring and providing protection against external threats. Soldiers will be the early adopters and beneficiaries of this new technology, integrated with AI systems using predictive physiological models and mission-relevant tools to enhance survivability in austere environments,” Friedl says.

“The convergence of classical fibers and fabrics with computation and machine learning has only begun. We are exploring this exciting future not only through research and field testing, but importantly in an MIT Department of Materials Science and Engineering course ‘Computing Fabrics,’ taught with Professor Anais Missakian from the Rhode Island School of Design,” adds Fink.

This research was supported, in part, by the U.S. Army Research Office Institute for Soldier Nanotechnology (ISN), the U.S. Defense Threat Reduction Agency, the U.S. National Science Foundation, the Fannie and John Hertz Foundation Fellowship, the Paul and Daisy Soros Foundation Fellowship for New Americans, the Stanford-Knight Hennessy Scholars Program, and the Astronaut Scholarship Foundation.

High dependence on fossil carbon, associated high carbon footprint, low recycling rates and microplastics: several solutions are emerging.

The evolution of the demand for textile fibres from 1960 to the present day shows how the textile industry found itself in this dilemma. In 1960, around 95% of textile fibres were of natural origin, from bio-based carbon, and there was no problem with microplastics, all fibres were biodegradable.

The explosion in demand – 650% between 1960 and 2023 – could only be met by synthetic fibres from the chemical and plastics industries. Their share grew from 3% in 1960 to 68% in 2023 and from less than 700,000 tonnes to 85 million tonnes/year (The Fiber Year 2024). The new fibres covered a wide range of properties, could even achieve previously unknown properties and, above all, thanks to a powerful and innovative chemical and plastics industry, production volumes could be rapidly increased and comparatively low prices realised.
 
At the same time, sustainability has declined, the carbon footprint of the textiles has increased significantly and the issue of microplastics requires solutions.

The first step would be to significantly increase the proportion of renewable fibres, as this is the only way to reduce dependence on fossil carbon, especially in the form of crude oil, and thus reduce the carbon footprint. But how can this be done? As defined by the Renewable Carbon Initiative, renewable carbon comes from biomass, CO₂ and recycling: From carbon above ground. This addresses the core problem of climate change, which is extracting and using additional fossil carbon from the ground that will end up in the atmosphere.
 
What can cotton, bast fibres and wool contribute?
Cotton fibre production can hardly be increased, it is stagnating between 20 and max. 25 million tonnes/year. Cultivated areas can hardly be expanded, and existing areas are salinized by the irrigation required. With the exception of about 1% organic cotton, significant amounts of pesticides are used. The market share of “preferred” cotton – defined by a list of recognized programmes – will fall from 27% of total cotton production in 2019/20 to 24% in 2020/21, after years of growth. (Textile Exchange, October 2022: Preferred Fiber & Materials Market Report) Bast fibres such as jute (75%), flax, hemp, ramie or kenaf would require a huge boost in technology development and capacity investment and will nevertheless probably remain more expensive than cotton, simply because bast fibres are much more complicated to process, e.g. separating the fibre from the stalk, which is not necessary for cotton as a fruit fibre. As a source of cellulose fibre, bast fibres will remain more expensive than wood.

Although bast fibres are more sustainable than many other fibres, there is unlikely to be a major change – unless China focuses on bast fibres as a substitute for cotton. Plans to do so have been put on hold due to technological problems.

The importance of man-made cellulosic fibres (MMCFs) or simply cellulose fibres
Cellulose fibre production has been growing steadily over the last decades, reaching an all-time high of nearly 8 million tonnes in 2023, and is expected to grow further to 11 million tonnes in 2030. Cellulosic fibres are the only bio-based and biodegradable fibres that cover a wider range of properties and applications and can rapidly increase their capacity. The raw materials can be virgin wood as well as all types of cellulosic waste streams from forestry, agriculture, cotton processing waste, textile waste and paper waste. Increasing the share of cellulosic fibres will therefore play a crucial role in solving the sustainability challenges of the textile industry.

The production of MMCFs includes viscose, lyocell, modal, acetate and cupro. The market share of FSC and/or PEFC certified MMCF increased from 55–60% in 2020 to 60–65% of all MMCF in 2021. The market share of “recycled MMCFs” increased to an estimated share of 0.5%. Much research and development is underway. As a result, the volumes of recycled MMCFs are expected to increase significantly in the coming years. (Textile Exchange, October 2022: Preferred Fiber & Materials Market Report)

The CEPI study “Forest-Based Biorefineries: Innovative Bio-Based Products for a Clean Transition” (renewable-carbon.eu/publications/product/innovative-bio-based-products-for-a-clean-transition-pdf/) identified 143 biorefineries in Europe, of which 126 are operational and 17 are planned. Most of them are based on chemical pulping (67%) – the precursor of cellulose fibres. Most biorefineries are located in Sweden, Finland, Germany, Portugal and Austria. But there are already biorefineries in operation or planned in 18 different European countries.

The global report “Is there enough biomass to defossilise the Chemicals and Derived Materials Sector by 2050?” (upcoming publication end of February 2025, available here: renewablecarbon.eu/publications) shows particularly high growth in dissolving/chemical pulp (from 9 in 2020 to 44 million tonnes in 2050; growth of 406%), cellulose fibres (from 7 in 2020 to 38 million tonnes in 2050; growth of 447%) and cellulose derivatives (from 2 in 2020 to 6 million tonnes in 2050; growth of 190%).

Biosynthetics – Bio-based and CO₂-based Synthetic Fibres
To further reduce the share of fossil-based synthetic fibres, bio-based polymer fibres (also called “biosynthetics”) are an excellent option because of their wide range of properties – only the implementation will take decades as the share today is only below 0.5%. There are many options, such as polyester fibres (PLA, PTT, PEF, PHA), polyolefin fibres (PE/PP), bio-based PA fibres from castor oil. PTT, for example, is well established in the US carpet market and PLA in the hygiene market. They are all bio-based, but only a few are also biodegradable (PLA, PHA).
 
Biosynthetics are one of many applications of bio-based polymers. In general, 17 bio-based polymers are currently commercially available with an installed capacity of over 4 million tonnes in 2023. Ten of these bio-based polymers are used as biosynthetics. resulting in the production of over one million tonnes of biosynthetics (nova report: Bio-based Building Blocks and Polymers – Global Capacities, Production and Trends 2023–2028, renewable-carbon.eu/publications/product/bio-based-buildingblocks-and-polymers-global-capacities-production-and-trends-2023-2028-short-version/).

In principle, many fibres can also be made from CO₂, but here the technology and capacity needs to be developed, perhaps in parallel with the production of sustainable aviation fuels from CO₂, which will become mandatory.

Circular Economy – Recycling of Textile Waste & Fibre-to-Fibre Recycling
The textile industry is at a pivotal moment, where sustainability is no longer an option but a necessity. As the environmental impact of textile production and disposal becomes increasingly clear, the pressure to adopt circular economy principles is growing.

One promising solution is fibre-to-fibre recycling, a process that converts used textiles into new, highquality fibres, effectively closing the waste loop. While significant progress has been made in the European Union, challenges remain, particularly in scaling up technologies, lack of collection systems and handling of mixed fibre textiles. Europe currently generates approximately 6.95 (1.25 + 5.7) million tonnes of textile waste per year, of which only 1.95 million tonnes is collected separately and 1.02 million tonnes is treated by recycling or backfilling.
 
The recycling of textiles reduces the demand for virgin fibres and the textile footprint. The share of recycled fibres increased slightly from 8.4% in 2020 to 8.9% in 2021, mainly due to an increase in bottlebased PET fibres. However, in 2021, less than 1% of the global fibre market will come from pre- and post-consumer recycled textiles (Textile Exchange, October 2022: Preferred Fiber & Materials Market Report). New regulations from Brussels for closed-loop recycling, especially bottle-to-bottle recycling, could threaten the use of bottle-based PET fibres in the textile industry. This would mean a reduction in recycling rates in the textile industry until the logistics and technologies are in place to recycle textiles on a large scale. This will be necessary to contribute to the circular economy. Several research projects are underway to find solutions and first pilot implementations are available.

The Future of Sustainable Textiles
The sustainable textile industry of the future will be built on a foundation of cotton fibres and fast-growing cellulose fibres, later strongly supported by bio- and CO₂-based synthetic fibres (“biosynthetics”), and high recycling rates for all types of fibres. This combination can eventually replace most fossil-based synthetic fibres by 2050.

To get the latest information on cellulose fibres, the nova-Institute organises the “Cellulose Fibres Conference” every year, which will take place next time in Cologne on 12 and 13 March 2025 – this year for the first time with biosynthetics.

For many years researchers from Nordic countries have worked for making textile industry more sustainable. Now there are prototypes of cotton which can clean itself and of textiles which are created of invasive lupines.  

How could future clothes and textiles become more ecofriendly, smart and sustainable? A research group from Nordic countries has tried to figure out this for many years and in October the prototypes they have made were presented in an exhibition in Turku.

A doctoral researcher Alicja Lawrynowicz from Faculty of Technology at the University of Turku has been developing two different smart textiles. In one of the projects researchers have created a cotton fabric which can clean itself without water.

This is possible because the fabric has been treated with mineral called zinc oxide.
 
The mineral forms a self-cleaning layer and stains on the fabric disappear when they are exposed to the daylight, in other words ultraviolet light. If stains disappear by themselves, it reduces the need of washing and garment burdens nature less.

Here you can see how the stains gradually disappear on the white cotton fabric that has been treated with zinc oxide.

In the other textile project, researchers have managed to develop non-toxic textile print which changes its colour when it is subjected to sunlight. Mineral hackmanite, which reacts to ultraviolet radiation, is used here. The mineral does not originate from mines but is created in a laboratory in Turku.

For first time ever, hackmanite is now used in textile prints. The mineral works as an ultraviolet censor and changes its colour when you have been too long time in the sun and must protect yourself. It can reduce the risk for the damage of the sun, says Alicja Lawrynowicz.

Material out to the market
Prototypes which now have been retrieved are not yet available in larger scale. So, what is going to happen with all discoveries?
The idea is that they are not going to stay in the laboratory. We hope that in the future our innovations will be used in industry, says Lawrynowicz.

The research is multidisciplinary, which means that there has been cooperation between different research groups. Research goes on also in other Nordic countries.  

Lupine can become textiles
In Denmark one research group has invested in ecofriendly colouring and created dyes out of big amounts of waste from local restaurants, among others avocado and onion peels. Avocado peels give textiles a beautiful yellow colour and onion creates brown nuances. In future these colours could replace traditional, toxic dyes.

At the same time researchers in Aalto University have produced textiles out of lupine, which is an invasive species in Finland.

Until now we have been removing lupines out of ditches and seeing it as a problem, but here researchers have created fibers and been able to weave a cloth out of it, says research coordinator Helen Salminen from the field of material science at the University of Turku.

Within the framework of the project researchers in Sweden have in turn worked on developing alternatives to plastic fibers (elastane) which are often used in jeans fabric for making fabric more elastic.

Cotton which contains a few percent of plastic fibers is difficult to recycle. This makes it difficult to use the fabric as a raw material for further processes. For that reason, it is important to find new ways to weave fabric so that fabric can be recycled and can be elastic without plastic fibers, says Alicja Lawrynowicz.

Together with Fiber Engineering GmbH, the DITF presents a process for the production of biodegradable plant pots. The products are cost effective and competitive. At the same time, the production process combats the spread of the invasive water hyacinth, whose biomass serves as the raw material for the plant pots.

Combating an invasive species and reaping economic benefits at the same time? What sounds like a contradiction in terms has been successfully achieved by DITF scientists in a joint project with several companies.

Water hyacinth is a rapidly spreading plant that has been recognized as a threat to existing ecosystems in many countries around the world. In particular, Lake Victoria in Africa is suffering from the widespread spread of water hyacinth. Fish deaths due to oxygen depletion, the production of climate-damaging methane gas during decomposition, and the obstruction of shipping and energy production are among the most prominent problems. They offer a grim preview of what is on the horizon in many other countries. As an invasive species, water hyacinth is spreading into many ecosystems around the world as a result of human activities, threatening the quality of human life.

Several approaches have been taken to control the spread of water hyacinth. The main focus is on removing the carpet of plants from the water and then recycling the resulting biomass. This is also the starting point for the research project co-led by the DITF, which aims to produce a new, cost-effective composite material from the fibrous plant material. The result is a prototype plant pot that is competitive and meets all the technical requirements of the project objectives.

At the beginning of the project, the project partners defined the material requirements for the plant pot. These include good dimensional stability, which must also be ensured when the pot is filled with wet soil. The use of physiologically harmless materials for contact with food plants is also an important requirement, as is a cost-effective and therefore competitive production method. However, the main focus is on complete biodegradability and thus the unrestricted compostability of the plant pot.

The biomaterial for the production of the plant pots comes from Louisiana and is directly marketed by In-Between International under the product name CYNTHIA®. This raw material has been extensively tested and modified at the DITF with regard to its composition and suitability for technical processing. It consists mainly of cellulose and must first be screened and treated with a hydrophobic agent for further processing. Hydrophobing is necessary to give the plant pots a certain resistance to moisture.

The prepared raw material now needs to be combined with a binder. The binder binds the plant fibers and ensures the dimensional stability of the plant pot. Laboratory tests with various binders have identified those that guarantee good processability and dimensional stability of the fiber composite. A thermoplastic was selected that was easy to process in a hot press and that fully met the requirements for biodegradability.

Further laboratory tests determined the ideal ratio of binder to fiber raw material. Tests in an industrial composting plant showed that the material was fully biodegradable and that the plant pots would decompose within a reasonable period of time - a stability of 4-6 weeks was the project goal.

The researchers produced test samples for all these preliminary tests in the form of fiber composite panels on a hot press. The next step was to produce the first prototypes of plant pots from the pre-treated fiber material with the appropriate binder. This part was carried out by the project partner, Fiber Engineering GmbH from Karlsruhe. This company has extensive expertise in the field of fiber injection molding (FIM), which makes it possible to produce 3-dimensional molded parts from fibers in simple and fast process steps. Fiber Engineering GmbH has optimized its existing process for processing the water hyacinth fiber material. It produced a series of plant pots and thus realized the last step of the project objective.

A cost calculation, taking into account all the materials and processes used, confirmed that the plant pots could be produced extremely cheaply at a production price of less than five cents per pot, making them marketable. In daily use, garden centers will appreciate the haptic advantages - strength and moisture resistance despite the fact that the material is completely biodegradable. The fact that the material used is helping to solve a global environmental problem should be another plus when it comes to marketing the product.

A consortium of seven companies across five countries has jointly established a supply chain for more sustainable polyester fiber. Instead of fossil materials, renewable and bio-based materials as well as carbon capture and utilization (CCU*) will be used in the manufacturing of polyester fibers for The North Face brand in Japan. The consortium parties are Goldwin, in the role of project owner, Mitsubishi Corporation, Chiyoda Corporation (all three from Japan), SK geo centric (South Korea), Indorama Ventures (Thailand), India Glycols (India) and Neste.

Neste will provide renewable Neste RE™ as one of the required ingredients for polyester production. The polyester fiber produced in the project is planned to be used by Goldwin for a part of The North Face products, including sports uniforms, in July 2024. After that, the launch of further Goldwin products and brands will be considered.

The seven companies apply a mass balancing approach to ensure credible traceability of material streams throughout the supply chain and will jointly continue to proactively promote the defossilization of materials to contribute to a more sustainable society.

Neste (NESTE, Nasdaq Helsinki) uses science and innovative technology to transform waste and other resources into renewable fuels and circular raw materials. The company creates solutions for combating climate change and accelerating a shift to a circular economy. Being the world’s leading producer of sustainable aviation fuel (SAF) and renewable diesel and a forerunner in developing renewable and circular feedstock solutions for polymers and chemicals, the company aims to help its customers to reduce their greenhouse gas emissions by at least 20 million tons annually by 2030.

The company’s ambition is to make the Porvoo oil refinery in Finland the most sustainable refinery in Europe. Neste is committed to reaching carbon-neutral production by 2035, and will reduce the carbon emission intensity of sold products by 50% by 2040. Neste has also set high standards for biodiversity, human rights and the supply chain. The company has consistently been included in the CDP and the Global 100 lists of the world’s most sustainable companies. In 2023, Neste's revenue stood at EUR 22.9 billion

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.

Developed by the Self-Assembly Lab, the 4D Knit Dress uses several technologies to create a custom design and a custom fit, while addressing sustainability concerns.

Until recently, bespoke tailoring — clothing made to a customer’s individual specifications — was the only way to have garments that provided the perfect fit for your physique. For most people, the cost of custom tailoring is prohibitive. But the invention of active fibers and innovative knitting processes is changing the textile industry.

“We all wear clothes and shoes,” says Sasha MicKinlay MArch ’23, a recent graduate of the MIT Department of Architecture. “It’s a human need. But there’s also the human need to express oneself. I like the idea of customizing clothes in a sustainable way. This dress promises to be more sustainable than traditional fashion to both the consumer and the producer.”

McKinlay is a textile designer and researcher at the Self-Assembly Lab who designed the 4D Knit Dress with Ministry of Supply, a fashion company specializing in high-tech apparel. The dress combines several technologies to create personalized fit and style. Heat-activated yarns, computerized knitting, and robotic activation around each garment generates the sculpted fit. A team at Ministry of Supply led the decisions on the stable yarns, color, original size, and overall design.

“Everyone’s body is different,” says Skylar Tibbits, associate professor in the Department of Architecture and founder of the Self-Assembly Lab. “Even if you wear the same size as another person, you're not actually the same.”

Active textiles
Students in the Self-Assembly Lab have been working with dynamic textiles for several years. The yarns they create can change shape, change property, change insulation, or become breathable. Previous applications to tailor garments include making sweaters and face masks. Tibbits says the 4D Knit Dress is a culmination of everything the students have learned from working with active textiles.

McKinlay helped produce the active yarns, created the concept design, developed the knitting technique, and programmed the lab’s industrial knitting machine. Once the garment design is programmed into the machine, it can quickly produce multiple dresses. Where the active yarns are placed in the design allows for the dress to take on a variety of styles such as pintucks, pleats, an empire waist, or a cinched waist.

“The styling is important,” McKinlay says. “Most people focus on the size, but I think styling is what sets clothes apart. We’re all evolving as people, and I think our style evolves as well. After fit, people focus on personal expression.”

Danny Griffin MArch ’22, a current graduate student in architectural design, doesn’t have a background in garment making or the fashion industry. Tibbits asked Griffin to join the team due to his experience with robotics projects in construction. Griffin translated the heat activation process into a programmable robotic procedure that would precisely control its application.

“When we apply heat, the fibers shorten, causing the textile to bunch up in a specific zone, effectively tightening the shape as if we’re tailoring the garment,” says Griffin. “There was a lot of trial and error to figure out how to orient the robot and the heat gun. The heat needs to be applied in precise locations to activate the fibers on each garment. Another challenge was setting the temperature and the timing for the heat to be applied.”

“We couldn’t use a commercial heat gun — which is like a handheld hair dryer — because they’re too large,” says Griffin. “We needed a more compact design. Once we figured it out, it was a lot of fun to write the script for the robot to follow.”

A dress can begin with one design — pintucks across the chest, for example — and be worn for months before having heat re-applied to alter its look. Subsequent applications of heat can tailor the dress further.

Beyond fit and fashion
Efficiently producing garments is a “big challenge” in the fashion industry, according to Gihan Amarasiriwardena ’11, the co-founder and president of Ministry of Supply.

“A lot of times you'll be guessing what a season's style is,” he says. “Sometimes the style doesn't do well, or some sizes don’t sell out. They may get discounted very heavily or eventually they end up going to a landfill.”

“Fast fashion” is a term that describes clothes that are inexpensive, trendy, and easily disposed of by the consumer. They are designed and produced quickly to keep pace with current trends. The 4D Knit Dress, says Tibbits, is the opposite of fast fashion. Unlike the traditional “cut-and-sew” process in the fashion industry, the 4D Knit Dress is made entirely in one piece, which virtually eliminates waste.

“From a global standpoint, you don’t have tons of excess inventory because the dress is customized to your size,” says Tibbits.

McKinlay says she hopes use of this new technology will reduce the amount of waste in inventory that retailers usually have at the end of each season.

“The dress could be tailored in order to adapt to these changes in styles and tastes,” she says. “It may also be able to absorb some of the size variations that retailers need to stock. Instead of extra-small, small, medium, large, and extra-large sizes, retailers may be able to have one dress for the smaller sizes and one for the larger sizes. Of course, these are the same sustainability points that would benefit the consumer.”

The Self-Assembly Lab has collaborated with Ministry of Supply on projects with active textiles for several years. Late last year, the team debuted the 4D Knit Dress at the company’s flagship store in Boston, complete with a robotic arm working its way around a dress as customers watched. For Amarasiriwardena, it was an opportunity to gauge interest and receive feedback from customers interested in trying the dress on.

“If the demand is there, this is something we can create quickly” unlike the usual design and manufacturing process, which can take years, says Amarasiriwardena.

Griffin and McKinlay were on hand for the demonstration and pleased with the results. For Griffin, with the “technical barriers” overcome, he sees many different avenues for the project.

“This experience leaves me wanting to try more,” he says.

McKinlay too would love to work on more styles.

“I hope this research project helps people rethink or reevaluate their relationship with clothes,” says McKinlay. “Right now when people purchase a piece of clothing it has only one ‘look.’ But, how exciting would it be to purchase one garment and reinvent it to change and evolve as you change or as the seasons or styles change? I'm hoping that's the takeaway that people will have.”

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

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

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

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

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

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

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

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