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Hotel guests who can customize their rooms by selecting the layout, snack bar offerings, and softness of the pillows are more likely to become loyal customers of that hotel and recommend it to others.
 
A new study published in Cornell Hospitality Quarterly finds that guests who gain some sense of ownership for their hotel room show a greater attachment to the brand after they check out. Encouraging “psychological ownership” of hotel rooms offers a new, cost-effective strategy to enhance customer loyalty, said study coauthor Suzanne Shu, dean of faculty and research at Cornell University’s SC Johnson College of Business and John S. Dyson Professor of Marketing at the Charles H. Dyson School of Applied Economics and Management.
 
“These very small interventions, including allowing people to choose their room at the time of check-in or encouraging them to move the furniture around, can have a big impact on the sense of ownership that people feel and the loyalty they have towards the hotel,” Shu said.

The paper, “Increasing Hotel Loyalty through Psychological Ownership,” relied on four separate studies that showed the tangible benefits of increasing guests’ psychological ownership of their rooms. The study defined psychological ownership as a perceptual state that is “best described as the territorial feeling that something is ‘mine.’”

The impact of psychological ownership of hotel rooms
While the concept of psychological ownership has been used to study employee behavior in organizational settings, Shu and one of the paper’s coauthors, Joann Peck, a professor of marketing at the University of Wisconsin-Madison, were the first researchers to apply it to the field of marketing in a paper published in 2009.

Shu compared the concept to the sales process involving a consumer who test-drives a car and begins to feel attached to it even before making an offer on it. “What our research shows is that that will affect decisions like how much you’re willing to pay for it, because you really think of it as yours and value it a lot more,” she said.     

After exploring the concept’s effect on public spaces like parks, Shu wanted to explore whether psychological ownership would apply to spaces that consumers don’t own, such as a hotel room. She and her coauthors created four experiments that tested whether three strategies that promote psychological ownership would have an impact on the hotel guest experience: controlling the space, investing oneself in it, and having intimate knowledge of it.

The first experiment they designed was conducted at the campus hotel at the University of Wisconsin-Madison, where they asked prospective guests to choose their hotel room from a map, allowing them to pick a layout and floor.

“The process didn’t make their check-in process any smoother, any shorter or more convenient, but it increased their willingness to be loyal to the hotel, come back to the hotel and refer this hotel to other people around them,” said Rin Yoon, a coauthor of the paper and a PhD candidate in marketing at the Samuel Curtis Johnson Graduate School of Management who will be teaching at the University of Iowa next fall.

In another experiment, the study analyzed a set of 14,689 reviews of a hotel in Hawaii on TripAdvisor. The assessment showed that guests who felt a sense of ownership for their hotel room wrote longer reviews and reported higher satisfaction levels on the app.

The study determined that guests who wrote reviews with the possessive pronouns “my” or “our” were more likely to have gained some sense of psychological ownership of their room. “That was a sign that they did feel ownership,” Shu said. “People aren’t going to say, ‘my room’ or ‘our room,’ unless they did feel some sense that it was theirs while they were there.”
 
The final two experiments created hypothetical check-ins online that included assessing whether a customer personalizing a room or using the hotel’s data based on previous preferences was more effective in promoting brand loyalty. The study found that guests who customized their room on their own showed greater loyalty to their hotel.

Applying the study’s results
Hotel chains have already begun using some of the strategies identified in the study, including allowing guests to personalize their rooms at check-in. That process forces guests to “exert their time and effort and invest themselves in their room,” which can promote loyalty, Yoon said.

Another strategy hotels could adopt to promote psychological ownership is allowing guests to rearrange some of the furniture in their rooms. That is exactly what Shu did during a recent hotel stay during a business trip.

“One of the first things I did to get myself set up to work was move the table a little bit closer to the window and prop the door open so I could get more sunlight from the outside,” she said. “If you allow a guest to customize their environment a little bit more, they’ll end up feeling more ownership over it because it’s like at home — they can customize their space.”

Lincoln Laboratory and MIT researchers are creating new types of bioabsorbable fabrics that mimic the unique way soft tissues stretch while nurturing growing cells.

Treating severe or chronic injury to soft tissues such as skin and muscle is a challenge in health care. Current treatment methods can be costly and ineffective, and the frequency of chronic wounds in general from conditions such as diabetes and vascular disease, as well as an increasingly aging population, is only expected to rise.

One promising treatment method involves implanting biocompatible materials seeded with living cells (i.e., microtissue) into the wound. The materials provide a scaffolding for stem cells, or other precursor cells, to grow into the wounded tissue and aid in repair. However, current techniques to construct these scaffolding materials suffer a recurring setback. Human tissue moves and flexes in a unique way that traditional soft materials struggle to replicate, and if the scaffolds stretch, they can also stretch the embedded cells, often causing those cells to die. The dead cells hinder the healing process and can also trigger an inadvertent immune response in the body.

"The human body has this hierarchical structure that actually un-crimps or unfolds, rather than stretches," says Steve Gillmer, a researcher in MIT Lincoln Laboratory's Mechanical Engineering Group. "That's why if you stretch your own skin or muscles, your cells aren't dying. What's actually happening is your tissues are uncrimping a little bit before they stretch."

Gillmer is part of a multidisciplinary research team that is searching for a solution to this stretching setback. He is working with Professor Ming Guo from MIT's Department of Mechanical Engineering and the laboratory's Defense Fabric Discovery Center (DFDC) to knit new kinds of fabrics that can uncrimp and move just as human tissue does.
The idea for the collaboration came while Gillmer and Guo were teaching a course at MIT. Guo had been researching how to grow stem cells on new forms of materials that could mimic the uncrimping of natural tissue. He chose electrospun nanofibers, which worked well, but were difficult to fabricate at long lengths, preventing him from integrating the fibers into larger knit structures for larger-scale tissue repair.

"Steve mentioned that Lincoln Laboratory had access to industrial knitting machines," Guo says. These machines allowed him to switch focus to designing larger knits, rather than individual yarns. "We immediately started to test new ideas through internal support from the laboratory."

Gillmer and Guo worked with the DFDC to discover which knit patterns could move similarly to different types of soft tissue. They started with three basic knit constructions called interlock, rib, and jersey.

"For jersey, think of your T-shirt. When you stretch your shirt, the yarn loops are doing the stretching," says Emily Holtzman, a textile specialist at the DFDC. "The longer the loop length, the more stretch your fabric can accommodate. For ribbed, think of the cuff on your sweater. This fabric construction has a global stretch that allows the fabric to unfold like an accordion."

Interlock is similar to ribbed but is knitted in a denser pattern and contains twice as much yarn per inch of fabric. By having more yarn, there is more surface area on which to embed the cells. "Knit fabrics can also be designed to have specific porosities, or hydraulic permeability, created by the loops of the fabric and yarn sizes," says Erin Doran, another textile specialist on the team. "These pores can help with the healing process as well."

So far, the team has conducted a number of tests embedding mouse embryonic fibroblast cells and mesenchymal stem cells within the different knit patterns and seeing how they behave when the patterns are stretched. Each pattern had variations that affected how much the fabric could uncrimp, in addition to how stiff it became after it started stretching. All showed a high rate of cell survival, and in 2024 the team received an R&D 100 award for their knit designs.

Gillmer explains that although the project began with treating skin and muscle injuries in mind, their fabrics have the potential to mimic many different types of human soft tissue, such as cartilage or fat. The team recently filed a provisional patent that outlines how to create these patterns and identifies the appropriate materials that should be used to make the yarn. This information can be used as a toolbox to tune different knitted structures to match the mechanical properties of the injured tissue to which they are applied.

"This project has definitely been a learning experience for me," Gillmer says. "Each branch of this team has a unique expertise, and I think the project would be impossible without them all working together. Our collaboration as a whole enables us to expand the scope of the work to solve these larger, more complex problems."

Researchers have developed comfortable, washable ‘smart pyjamas’ that can monitor sleep disorders such as sleep apnoea at home, without the need for sticky patches, cumbersome equipment or a visit to a specialist sleep clinic.

The team, led by the University of Cambridge, developed printed fabric sensors that can monitor breathing by detecting tiny movements in the skin, even when the pyjamas are worn loosely around the neck and chest.

The sensors embedded in the smart pyjamas were trained using a ‘lightweight’ AI algorithm and can identify six different sleep states with 98.6% accuracy, while ignoring regular sleep movements such as tossing and turning. The energy-efficient sensors only require a handful of examples of sleep patterns to successfully identify the difference between regular and disordered sleep.

The researchers say that their smart pyjamas could be useful for the millions of people in the UK who struggle with disordered sleep to monitor their sleep, and how it might be affected by lifestyle changes. The results are reported in the Proceedings of the National Academy of Sciences (PNAS).

Sleep is vital for human health, yet more than 60% of adults experience poor sleep quality, leading to the loss of between 44 and 54 annual working days, and an estimated one percent reduction in global GDP. Sleep behaviours such as mouth breathing, sleep apnoea and snoring are major contributors to poor sleep quality, and can lead to chronic conditions such as cardiovascular disease, diabetes and depression.

“Poor sleep has huge effects on our physical and mental health, which is why proper sleep monitoring is vital,” said Professor Luigi Occhipinti from the Cambridge Graphene Centre, who led the research. “However, the current gold standard for sleep monitoring, polysomnography or PSG, is expensive, complicated and isn’t suitable for long-term use at home.”

Home devices that are simpler than PSG, such as home sleep tests, typically focus on a single condition and are bulky or uncomfortable. Wearable devices such as smartwatches, while more comfortable to wear, can only infer sleep quality, and are not effective for accurately monitoring disordered sleep.

“We need something that is comfortable and easy to use every night, but is accurate enough to provide meaningful information about sleep quality,” said Occhipinti.

To develop the smart pyjamas, Occhipinti and his colleagues built on their earlier work on a smart choker for people with speech impairments. The team re-designed the graphene-based sensors for breath analysis during sleep, and made several design improvements to increase sensitivity.

“Thanks to the design changes we made, the sensors are able to detect different sleep states, while ignoring regular tossing and turning,” said Occhinpinti. “The improved sensitivity also means that the smart garment does not need to be worn tightly around the neck, which many people would find uncomfortable. As long as the sensors are in contact with the skin, they provide highly accurate readings.”

The researchers designed a machine learning model, called SleepNet, that uses the signals captured by the sensors to identify sleep states including nasal breathing, mouth breathing, snoring, teeth grinding, central sleep apnoea (CSA), and obstructive sleep apnoea (OSA). SleepNet is a ‘lightweight’ AI network, that reduces computational complexity to the point where it can be run on portable devices, without the need to connect to computers or servers.

“We pruned the AI model to the point where we could get the lowest computational cost with the highest degree of accuracy,” said Occhinpinti. “This way we are able to embed the main data processors in the sensors directly.”

The smart pyjamas were tested on healthy patients and those with sleep apnoea, and were able to detect a range of sleep states with an accuracy of 98.6%. By treating the smart pyjamas with a special starching step, they were able to improve the durability of the sensors so they can be run through a regular washing machine.

The most recent version of the smart pyjamas are also capable of wireless data transfer, meaning the sleep data can be securely transferred to a smartphone or computer.
“Sleep is so important to health, and reliable sleep monitoring can be key in preventative care,” said Occhipinti. “Since this garment can be used at home, rather than in a hospital or clinic, it can alert users to changes in their sleep that they can then discuss with their doctor. Sleep behaviours such as nasal versus mouth breathing are not typically picked up in an NHS sleep analysis, but it can be an indicator of disordered sleep.”

The researchers are hoping to adapt the sensors for a range of health conditions or home uses, such as baby monitoring, and have been in discussions with different patient groups. They are also working to improve the durability of the sensors for long-term use.

The research was supported in part by the EU Graphene Flagship, Haleon, and the Engineering and Physical Sciences Research Council (EPSRC), part of UK Research and Innovation (UKRI).

Cornell researchers have developed an elegant and sustainable way to clean up waterways: reusing one waste product to remove another.

Led by Larissa Shepherd, Ph.D., assistant professor in the Department of Human Centered Design, in the College of Human Ecology, the team has proposed using discarded silk yarn for the removal of dye and oil from water. Studies on several different forms of silk: fabrics, yarns, and fibers revealed that yarn unraveled from silk fabric, soaked up methylene blue (MB), a common textile dye, from water at a substantially higher rate than other forms of silk they tested.
 
What’s more, the silk yarn can be cleaned and reused. Shepherd’s group found that the textile can withstand at least 10 cycles, with minimal loss of functionality.
 
Shepherd is the corresponding author of “Waste Bombyx Mori Silk Textiles as Efficient and Reuseable Bio-Adsorbents for Methylene Blue Dye Removal and Oil-Water Separation,” published in November 2024 in the journal Fibers. Co-authors are Hansadi Jayamaha, doctoral candidate in the field of fiber science, and Isabel Schorn ’26, a fiber science undergraduate.

Jayamaha found that 12 milligrams of silk filament yarn have 90% MB dye removal efficiency within 10 minutes of exposure, for concentrations up to 100 parts per million, substantially greater than the efficiency of other forms – even electrospun fiber mats or fabrics treated with the hollow silk microparticle spheres, which was a surprise, the researchers said.

“By creating the spheres,” Jayamaha said, “we were creating a more hydrophilic surface compared to the silk fabric, which is more hydrophobic. But by disassembling the fabric to the yarn stage, we are creating higher surface area, and that improves the adsorption.”

The group also tested silk textile adsorption capacity with oil, and found that Noil fabric (a textile that contains silk yarns composed of short fibers, rather than filament) displays oil adsorption capacities three times the initial weight of the fabric for corn oil, and close to twice the weight for gasoline.

Tests on both materials showed that, following a diminishment of function after the first cleaning-reuse cycle, the material maintained its functionality for the subsequent nine cycles.
This intrinsic property of silk as a dye adsorbent, the group found, can be achieved without chemical or other alteration of the material – just deconstructing the textile product.
     
“When you regenerate silk, you have to use very harsh chemicals,” Shepherd said. “In our case, we’re just using the fabrics themselves. Yes, we may have to unravel them to get the benefit, but that’s much better than putting these harsh chemicals out into the environment.”

Shepherd envisions “pillows” containing the silk yarn unraveled from discarded textiles and remnants from the cut and sew operations of the textiles industry as being an effective means of cleaning up spills and waste materials, including MB dye, which is detrimental to agricultural land and waterways when it is accidentally released from textile plants.

“We realized that we can kill two birds with one stone: We can get rid of waste textiles, which is a big issue in the textile industry in general,” Shepherd said. “And then we found that it’s actually really good at adsorbing, just because of its natural, structural properties.”

This work made use of the Cornell Center for Materials Research Shared Facilities, as well as the Cornell NanoScale Science and Technology Facility, a member of the National Nanotechnology Coordinated Infrastructure, which is supported by the National Science Foundation. This work was partially funded by an American Association of Textiles Chemists and Colorists graduate research grant.

Membranes based on natural silk and cellulose can remove many contaminants, including “forever chemicals” and heavy metals.

Water contamination by the chemicals used in today’s technology is a rapidly growing problem globally. A recent study by the U.S. Centers for Disease Control found that 98 percent of people tested had detectable levels of PFAS, a family of particularly long-lasting compounds also known as “forever chemicals,” in their bloodstream.

A new filtration material developed by researchers at MIT might provide a nature-based solution to this stubborn contamination issue. The material, based on natural silk and cellulose, can remove a wide variety of these persistent chemicals as well as heavy metals. And, its antimicrobial properties can help keep the filters from fouling.

The findings are described in the journal ACS Nano, in a paper by MIT postdoc Yilin Zhang, professor of civil and environmental engineering Benedetto Marelli, and four others from MIT.

PFAS chemicals are present in a wide range of products, including cosmetics, food packaging, water-resistant clothing, firefighting foams, and antistick coating for cookware. A recent study identified 57,000 sites contaminated by these chemicals in the U.S. alone. The U.S. Environmental Protection Agency has estimated that PFAS remediation will cost $1.5 billion per year, in order to meet new regulations that call for limiting the compound to less than 7 parts per trillion in drinking water.

Contamination by PFAS and similar compounds “is actually a very big deal, and current solutions may only partially resolve this problem very efficiently or economically,” Zhang says. “That’s why we came up with this protein and cellulose-based, fully natural solution,” he says.

“We came to the project by chance,” Marelli notes. The initial technology that made the filtration material possible was developed by his group for a completely unrelated purpose — as a way to make a labelling system to counter the spread of counterfeit seeds, which are often of inferior quality. His team devised a way of processing silk proteins into uniform nanoscale crystals, or “nanofibrils,” through an environmentally benign, water-based drop-casting method at room temperature.

Zhang suggested that their new nanofibrillar material might be effective at filtering contaminants, but initial attempts with the silk nanofibrils alone didn’t work. The team decided to try adding another material: cellulose, which is abundantly available and can be obtained from agricultural wood pulp waste. The researchers used a self-assembly method in which the silk fibroin protein is suspended in water and then templated into nanofibrils by inserting “seeds” of cellulose nanocrystals. This causes the previously disordered silk molecules to line up together along the seeds, forming the basis of a hybrid material with distinct new properties.

By integrating cellulose into the silk-based fibrils that could be formed into a thin membrane, and then tuning the electrical charge of the cellulose, the researchers produced a material that was highly effective at removing contaminants in lab tests.

The electrical charge of the cellulose, they found, also gave it strong antimicrobial properties. This is a significant advantage, since one of the primary causes of failure in filtration membranes is fouling by bacteria and fungi. The antimicrobial properties of this material should greatly reduce that fouling issue, the researchers say.

“These materials can really compete with the current standard materials in water filtration when it comes to extracting metal ions and these emerging contaminants, and they can also outperform some of them currently,” Marelli says. In lab tests, the materials were able to extract orders of magnitude more of the contaminants from water than the currently used standard materials, activated carbon or granular activated carbon.

While the new work serves as a proof of principle, Marelli says, the team plans to continue working on improving the material, especially in terms of durability and availability of source materials. While the silk proteins used can be available as a byproduct of the silk textile industry, if this material were to be scaled up to address the global needs for water filtration, the supply might be insufficient. Also, alternative protein materials may turn out to perform the same function at lower cost.

Initially, the material would likely be used as a point-of-use filter, something that could be attached to a kitchen faucet, Zhang says. Eventually, it could be scaled up to provide filtration for municipal water supplies, but only after testing demonstrates that this would not pose any risk of introducing any contamination into the water supply. But one big advantage of the material, he says, is that both the silk and the cellulose constituents are considered food-grade substances, so any contamination is unlikely.

“Most of the normal materials available today are focusing on one class of contaminants or solving single problems,” Zhang says. “I think we are among the first to address all of these simultaneously.”

“What I love about this approach is that it is using only naturally grown materials like silk and cellulose to fight pollution,” says Hannes Schniepp, professor of applied science at the College of William and Mary, who was not associated with this work. “In competing approaches, synthetic materials are used — which usually require only more chemistry to fight some of the adverse outcomes that chemistry has produced. [This work] breaks this cycle! ... If this can be mass-produced in an economically viable way, this could really have a major impact.”

The research team included MIT postdocs Hui Sun and Meng Li, graduate student Maxwell Kalinowski, and recent graduate Yunteng Cao PhD ’22, now a postdoc at Yale University. The work was supported by the U.S. Office of Naval Research, the U.S. National Science Foundation, and the Singapore-MIT Alliance for Research and Technology.

With applications in clothing, construction and food storage, the new textile reduces heat from both the sun and thermal radiation from nearby buildings.

This year has already seen massive heatwaves around the globe, with cities in Mexico, India, Pakistan and Oman hitting temperatures near or past 50 degrees Celsius (122 degrees Fahrenheit).  

As global temperatures and urban populations rise, the world’s cities have become “urban heat islands,” with tight-packed conditions and thermal radiation emitting from pavement and skyscraper trapping and magnifying these temperatures. With 68 percent of all people predicted to live in cities by 2050, this is a growing, deadly problem.

In a paper published in Science, researchers from the UChicago Pritzker School of Molecular Engineering (PME) detail a new wearable fabric that can help urban residents survive the worst impacts of massive heat caused by global climate change, with applications in clothing, building and car design, and food storage.  

In tests under the Arizona sun, the material kept 2.3 degrees Celsius (4.1 degrees Fahrenheit) cooler than the broadband emitter fabric used for outdoor endurance sports and 8.9 degrees Celsius (16 degrees Fahrenheit) cooler than the commercialized silk commonly used for shirts, dresses and other summer clothing.

This, the team hopes, will help many avoid the heat-related hospitalizations and deaths seen in global population centers this year alone.

“We need to reduce carbon emission and make our cities carbon negative or carbon neutral,” PME Asst. Prof. Po-Chun Hsu said. “But meanwhile, people are feeling the impact of these high temperatures.”

‘You have to consider the environment’
Existing cooling fabric for outdoor sports works by reflecting the sun’s light in a diffuse pattern so it doesn’t blind onlookers. But in an urban heat island, the sun is only one source of heat. While the sun bakes from above, thermal radiation emitted from buildings and pavement blast city-dwellers with blistering heat from the sides and below.

This means many materials that perform well in lab tests won’t help city-dwellers in Arizona, Nevada, California, Southeast Asia and China when predicted massive heatwaves hit them over the next few weeks.

“People normally focus on the performance or the material design of cooling textiles,” said co-first author Ronghui Wu, a postdoctoral researcher at PME. “To make a textile that has the potential to apply to real life, you have to consider the environment.”

One simple example of considering the environment is that people stand. They are wearing materials designed to reflect direct sunlight, but only their hats, shoulder coverings and the tops of their shoes – about 3 percent of their clothing – face that direct light. The other 97 of their clothes are being heated by the thermal radiation coming at them from the sides and below, which broadband emitter fabric does not fight.

The sun and sidewalk cook with different heats. Creating one material capable of protecting wearers from both provided a major engineering challenge for the team.

“Solar is visible light, thermal radiation is infrared, so they have different wavelengths. That means you need to have a material that has two optical properties at the same time. That's very challenging to do,” said co-first author Chenxi Sui, a PhD candidate at PME. “You need to play with material science to engineer and tune the material to give you different resonances at different wavelengths.”

The costs of comfort
Cooling a home too often means warming the planet, with the carbon impact of air conditioning and refrigeration systems contributing to climate change.  

“Our civilization actually uses about 10 to 15 percent of the energy in total just to make ourselves feel comfortable wherever we go,” Hsu said.

The risk from heat is not distributed evenly, however. In the U.S. and Japan, more than 90 percent of households have an air conditioner, a number that drops to 5 percent in India and parts of Africa.
 
The PME team’s new textile, which has received a provisional patent, can help provide a passive cooling system that can supplement and reduce the need for energy- and cost-intensive systems.

The applications go far beyond clothing.  

A thicker version of the fabric protected by an invisible layer of polyethylene could be used on the sides of buildings or cars, lowering internal temperatures and reducing the cost and carbon impact of air conditioning. Similarly, the material could be used to transport and store milk and other foods that would otherwise spoil in the heat, cutting refrigeration’s impact.

“You can save a lot of cooling, electricity and energy costs because this is a passive process,” Sui said.

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

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).

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.

For the first time, researchers have used bacteria to “upcycle” waste polyethylene: Move over Spider-Man: Researchers at Rensselaer Polytechnic Institute have developed a strain of bacteria that can turn plastic waste into a biodegradable spider silk with multiple uses.

Their new study marks the first time scientists have used bacteria to transform polyethylene plastic — the kind used in many single-use items — into a high-value protein product.

That product, which the researchers call “bio-inspired spider silk” because of its similarity to the silk spiders use to spin their webs, has applications in textiles, cosmetics, and even medicine.

“Spider silk is nature’s Kevlar,” said Helen Zha, Ph.D., an assistant professor of chemical and biological engineering and one of the RPI researchers leading the project. “It can be nearly as strong as steel under tension. However, it’s six times less dense than steel, so it’s very lightweight. As a bioplastic, it’s stretchy, tough, nontoxic, and biodegradable.”

All those attributes make it a great material for a future where renewable resources and avoidance of persistent plastic pollution are the norm, Zha said.

Polyethylene plastic, found in products such as plastic bags, water bottles, and food packaging, is the biggest contributor to plastic pollution globally and can take upward of 1,000 years to degrade naturally. Only a small portion of polyethylene plastic is recycled, so the bacteria used in the study could help “upcycle” some of the remaining waste.

Pseudomonas aeruginosa, the bacteria used in the study, can naturally consume polyethylene as a food source. The RPI team tackled the challenge of engineering this bacteria to convert the carbon atoms of polyethylene into a genetically encoded silk protein. Surprisingly, they found that their newly developed bacteria could make the silk protein at a yield rivaling some bacteria strains that are more conventionally used in biomanufacturing.

The underlying biological process behind this innovation is something people have employed for millennia.

“Essentially, the bacteria are fermenting the plastic. Fermentation is used to make and preserve all sorts of foods, like cheese, bread, and wine, and in biochemical industries it’s used to make antibiotics, amino acids, and organic acids,” said Mattheos Koffas, Ph.D., Dorothy and Fred Chau ʼ71 Career Development Constellation Professor in Biocatalysis and Metabolic Engineering, and the other researcher leading the project, and who, along with Zha, is a member of the Center for Biotechnology and Interdisciplinary Studies at Rensselaer.

To get bacteria to ferment polyethylene, the plastic is first “predigested,” Zha said. Just like humans need to cut and chew our food into smaller pieces before our bodies can use it, the bacteria has difficulty eating the long molecule chains, or polymers, that comprise polyethylene.

In the study, Zha and Koffas collaborated with researchers at Argonne National Laboratory, who depolymerized the plastic by heating it under pressure, producing a soft, waxy substance. Next, the team put a layer of the plastic-derived wax on the bottoms of flasks, which served as the nutrient source for the bacteria culture. This contrasts with typical fermentation, which uses sugars as the nutrient source.

“It’s as if, instead of feeding the bacteria cake, we’re feeding it the candles on the cake,” Zha said.

Then, as a warming plate gently swirled the flasks’ contents, the bacteria went to work. After 72 hours, the scientists strained out the bacteria from the liquid culture, purified the silk protein, and freeze dried it. At that stage, the protein, which resembled torn up cotton balls, could potentially be spun into thread or made into other useful forms.

“What’s really exciting about this process is that, unlike the way plastics are produced today, our process is low energy and doesn’t require the use of toxic chemicals,” Zha said. “The best chemists in the world could not convert polyethylene into spider silk, but these bacteria can. We’re really harnessing what nature has developed to do manufacturing for us.”

However, before upcycled spider silk products become a reality, the researchers will first need to find ways to make the silk protein more efficiently.

“This study establishes that we can use these bacteria to convert plastic to spider silk. Our future work will investigate whether tweaking the bacteria or other aspects of the process will allow us to scale up production,” Koffas said.

“Professors Zha and Koffas represent the new generation of chemical and biological engineers merging biological engineering with materials science to manufacture ecofriendly products. Their work is a novel approach to protecting the environment and reducing our reliance on nonrenewable resources,” said Shekhar Garde, Ph.D., dean of RPI’s School of Engineering.

The study, which was conducted by first author Alexander Connor, who earned his doctorate from RPI in 2023, and co-authors Jessica Lamb and Massimiliano Delferro with Argonne National Laboratory, is published in the journal “Microbial Cell Factories.”