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Waterfiltration Photo Manuel Darío Fuentes Hernández , Pixabay
10.11.2024

New filtration material could remove long-lasting chemicals from water

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.

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.

Image: MIT News; iStock
12.08.2024

Creating quiet spaces with sound-suppressing silk

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Source:

Adam Zewe | MIT News

(c) MIT Self Assembly Lab
29.04.2024

The 4D Knit Dress - Is this the future of fashion?

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.”

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.”

Source:

Maria Iacobo | Olivia Mintz | School of Architecture and Planning, MIT Department of Architecture

Smart glove teaches new physical skills Image: Alex Shipps/MIT CSAIL
18.03.2024

Smart glove teaches new physical skills

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Source:

Alex Shipps, MIT CSAIL

06.11.2023

Shape-shifting fiber can produce morphing fabrics

The low-cost FibeRobo, which is compatible with existing textile manufacturing techniques, could be used in adaptive performance wear or compression garments.

Researchers from MIT and Northeastern University developed a liquid crystal elastomer fiber that can change its shape in response to thermal stimuli. The fiber, which is fully compatible with existing textile manufacturing machinery, could be used to make morphing textiles, like a jacket that becomes more insulating to keep the wearer warm when temperatures drop.

The low-cost FibeRobo, which is compatible with existing textile manufacturing techniques, could be used in adaptive performance wear or compression garments.

Researchers from MIT and Northeastern University developed a liquid crystal elastomer fiber that can change its shape in response to thermal stimuli. The fiber, which is fully compatible with existing textile manufacturing machinery, could be used to make morphing textiles, like a jacket that becomes more insulating to keep the wearer warm when temperatures drop.

Instead of needing a coat for each season, imagine having a jacket that would dynamically change shape so it becomes more insulating to keep you warm as the temperature drops.
A programmable, actuating fiber developed by an interdisciplinary team of MIT researchers could someday make this vision a reality. Known as FibeRobo, the fiber contracts in response to an increase in temperature, then self-reverses when the temperature decreases, without any embedded sensors or other hard components.

The low-cost fiber is fully compatible with textile manufacturing techniques, including weaving looms, embroidery, and industrial knitting machines, and can be produced continuously by the kilometer. This could enable designers to easily incorporate actuation and sensing capabilities into a wide range of fabrics for myriad applications.

The fibers can also be combined with conductive thread, which acts as a heating element when electric current runs through it. In this way, the fibers actuate using electricity, which offers a user digital control over a textile’s form. For instance, a fabric could change shape based on any piece of digital information, such as readings from a heart rate sensor.

“We use textiles for everything. We make planes with fiber-reinforced composites, we cover the International Space Station with a radiation-shielding fabric, we use them for personal expression and performance wear. So much of our environment is adaptive and responsive, but the one thing that needs to be the most adaptive and responsive — textiles — is completely inert,” says Jack Forman, a graduate student in the Tangible Media Group of the MIT Media Lab, with a secondary affiliation at the Center for Bits and Atoms, and lead author of a paper on the actuating fiber.

He is joined on the paper by 11 other researchers at MIT and Northeastern University, including his advisors, Professor Neil Gershenfeld, who leads the Center for Bits and Atoms, and Hiroshi Ishii, the Jerome B. Wiesner Professor of Media Arts and Sciences and director of the Tangible Media Group. The research will be presented at the ACM Symposium on User Interface Software and Technology.

Morphing materials
The MIT researchers wanted a fiber that could actuate silently and change its shape dramatically, while being compatible with common textile manufacturing procedures. To achieve this, they used a material known as liquid crystal elastomer (LCE).

A liquid crystal is a series of molecules that can flow like liquid, but when they’re allowed to settle, they stack into a periodic crystal arrangement. The researchers incorporate these crystal structures into an elastomer network, which is stretchy like a rubber band.

As the LCE material heats up, the crystal molecules fall out of alignment and pull the elastomer network together, causing the fiber to contract. When the heat is removed, the molecules return to their original alignment, and the material to its original length, Forman explains.

By carefully mixing chemicals to synthesize the LCE, the researchers can control the final properties of the fiber, such as its thickness or the temperature at which it actuates.

They perfected a preparation technique that creates LCE fiber which can actuate at skin-safe temperatures, making it suitable for wearable fabrics.

“There are a lot of knobs we can turn. It was a lot of work to come up with this process from scratch, but ultimately it gives us a lot of freedom for the resulting fiber,” he adds.
However, the researchers discovered that making fiber from LCE resin is a finicky process. Existing techniques often result in a fused mass that is impossible to unspool.

Researchers are also exploring other ways to make functional fibers, such as by incorporating hundreds of microscale digital chips into a polymer, utilizing an activated fluidic system, or including piezoelectric material that can convert sound vibrations into electrical signals.

Fiber fabrication
Forman built a machine using 3D-printed and laser-cut parts and basic electronics to overcome the fabrication challenges. He initially built the machine as part of the graduate-level course MAS.865 (Rapid-Prototyping of Rapid-Prototyping Machines: How to Make Something that Makes [almost] Anything).

To begin, the thick and viscous LCE resin is heated, and then slowly squeezed through a nozzle like that of a glue gun. As the resin comes out, it is cured carefully using UV lights that shine on both sides of the slowly extruding fiber.

If the light is too dim, the material will separate and drip out of the machine, but if it is too bright, clumps can form, which yields bumpy fibers.

Then the fiber is dipped in oil to give it a slippery coating and cured again, this time with UV lights turned up to full blast, creating a strong and smooth fiber. Finally, it is collected into a top spool and dipped in powder so it will slide easily into machines for textile manufacturing.
From chemical synthesis to finished spool, the process takes about a day and produces approximately a kilometer of ready-to-use fiber.

“At the end of the day, you don’t want a diva fiber. You want a fiber that, when you are working with it, falls into the ensemble of materials — one that you can work with just like any other fiber material, but then it has a lot of exciting new capabilities,” Forman says.

Creating such a fiber took a great deal of trial and error, as well as the collaboration of researchers with expertise in many disciplines, from chemistry to mechanical engineering to electronics to design.

The resulting fiber, called FibeRobo, can contract up to 40 percent without bending, actuate at skin-safe temperatures (the skin-safe version of the fiber contracts up to about 25 percent), and be produced with a low-cost setup for 20 cents per meter, which is about 60 times cheaper than commercially available shape-changing fibers.

The fiber can be incorporated into industrial sewing and knitting machines, as well as nonindustrial processes like hand looms or manual crocheting, without the need for any process modifications.
The MIT researchers used FibeRobo to demonstrate several applications, including an adaptive sports bra made by embroidery that tightens when the user begins exercising.

They also used an industrial knitting machine to create a compression jacket for Forman’s dog, whose name is Professor. The jacket would actuate and “hug” the dog based on a Bluetooth signal from Forman’s smartphone. Compression jackets are commonly used to alleviate the separation anxiety a dog can feel while its owner is away.

In the future, the researchers want to adjust the fiber’s chemical components so it can be recyclable or biodegradable. They also want to streamline the polymer synthesis process so users without wet lab expertise could make it on their own.

Forman is excited to see the FibeRobo applications other research groups identify as they build on these early results. In the long run, he hopes FibeRobo can become something a maker could buy in a craft store, just like a ball of yarn, and use to easily produce morphing fabrics.

“LCE fibers come to life when integrated into functional textiles. It is particularly fascinating to observe how the authors have explored creative textile designs using a variety of weaving and knitting patterns,” says Lining Yao, the Cooper-Siegel Associate Professor of Human Computer Interaction at Carnegie Mellon University, who was not involved with this work.

This research was supported, in part, by the William Asbjornsen Albert Memorial Fellowship, the Dr. Martin Luther King Jr. Visiting Professor Program, Toppan Printing Co., Honda Research, Chinese Scholarship Council, and Shima Seiki. The team included Ozgun Kilic Afsar, Sarah Nicita, Rosalie (Hsin-Ju) Lin, Liu Yang, Akshay Kothakonda, Zachary Gordon, and Cedric Honnet at MIT; and Megan Hofmann and Kristen Dorsey at Northeastern University.

Source:

MIT and Northeastern University

From MIT to Burning Man: The Living Knitwork Pavilion Credit Irmandy Wicaksono
24.10.2023

From MIT to Burning Man: The Living Knitwork Pavilion

Set against the vast and surreal backdrop of the Black Rock Desert in Nevada, Burning Man is an annual gathering that transforms the flat, barren expanse into a vibrant playground for artistic and creative expression. Here, "Burners" come to both witness and contribute to the ephemeral Black Rock City, which participants build anew each year. With its myriad art installations and performances, Black Rock City is a temporary home for creative minds from around the world.

Set against the vast and surreal backdrop of the Black Rock Desert in Nevada, Burning Man is an annual gathering that transforms the flat, barren expanse into a vibrant playground for artistic and creative expression. Here, "Burners" come to both witness and contribute to the ephemeral Black Rock City, which participants build anew each year. With its myriad art installations and performances, Black Rock City is a temporary home for creative minds from around the world.

This year among the large-scale art stood the Living Knitwork Pavilion, an unusual architectural piece crafted from knitted textiles and a lattice network of wood. Developed and built by a team of researchers from the MIT Media Lab and MIT School of Architecture and Planning, and led by PhD student Irmandy Wicaksono, the installation received a 2023 Black Rock City Honorarium. For the team, it was a highly challenging and fulfilling project, full of learning and surprises. Seeing it emerge and illuminate in the middle of the desert was truly magical.

In the Living Knitwork Pavilion, 12 modular fabric panels, known as Knitwork petals, are connected through a central tower. The whole installation stood as a dodecagonal pyramid shade structure, 18 feet tall and 26 feet wide, resembling a teepee. The fabrics were developed using digital machine knitting and a collection of functional and common yarns, including photochromic, luminous, and conductive yarns. Taking inspiration from the intricacy of textile patterns and temple carvings of Indonesia, Wicaksono leveraged the tension between knitted polyester and spandex yarns to create textural textile patterns or reliefs. The fusion of parametric and hand-designed motifs transforms the "Living Knitwork" into a narrative artwork, reflecting both a reverence for ancient artistry and a vision of the future. These reliefs, full of symbols and illustrations, depict 12 stories of the future — from solarpunk cities and bio-machine interfaces to the deep ocean and space exploration.

Burning Man and the Black Rock Desert are famed for their climbing enthusiasts and intense winds. Given that strong winds can make the fabrics behave like sails, exerting significant force, the team designed a structure capable of supporting the weight of many climbers, and withstanding wind speeds of up to 70 mph.

The finalized central structure of the pavilion consists of an asymptotic lattice network of lumber and joint elements, optimized for structural integrity while minimizing material use. The knitwork petals, integrated with double-knit structure and mesh openings, and thermoformed through melting yarns, maintain structural stability. Tailored channels for ropes and cables were also incorporated into the knitting design, ensuring each fabric and electrical component is securely anchored and protected, without compromising visual elegance. Facing winds that reached 36 mph this year, the Living Knitwork Pavilion remained steadfast throughout the Burning Man event, demonstrating its resilience in extreme desert conditions.

In support of Burning Man's push for more sustainable art, the Living Knitwork Pavilion utilized additive manufacturing of digital knitting. This method allowed for the creation of custom multi-layer textiles that are both aesthetic and functional, all while minimizing raw material use and waste. The team incorporated recycled materials in their fabrics, with 60 percent of the yarns coming from recycled plastic bottles. The pavilion also runs entirely on battery power and solar cells. The team worked together with the Solar Library, a sculptural solar panel that distributes energy to other arts on the playa, to eliminate generators and noise while promoting the use of renewable energy sources.

By day, the Living Knitwork Pavilion served as a shade structure, while providing a communal space for meditation and discovery. As the sun shifts through the day, hidden-encrypted textile patterns and visual experience are revealed through photochromism and luminescent glow. As dusk descended upon the desert, the pavilion underwent a metamorphosis, illuminating its surroundings through an immersive lighting and audio system. Through a distributed network of antennas embedded within the central structure and each knitwork petal, the team’s ultimate goal was to create an intimate experience that allows individual and collective movement and activity to influence the overall ambience of the space, involving sound and illumination.

Throughout Burning Man, the pavilion also hosted pop-up events, from yoga sessions, dance performances, live music, and even a wedding ceremony. Unfortunately, in the last two days of the event, a heavy rainstorm hit the Black Rock Desert — a rarity for the event. Yet, this climatic twist worked in favor of the pavilion, helping cleanse its textile surface from the accumulated dust and reviving its vivid blue color.

The result of this grand project is a collaboration that transcends disciplinary boundaries. The research team aims to exemplify the remarkable possibilities that arise when architecture, technology, and textile arts converge and bring communities together.

The interdisciplinary group behind the Living Knitwork Pavilion includes researchers from across the Media Lab, the MIT Center for Bits and Atoms, and the Department of Architecture: Irmandy Wicaksono, Sam Chin, Alfonso Parra Rubio, Nicole Bakker, Erik Strand, Gabriela Advincula, Manaswi Mishra, Age van der Mei, Judyta Cichoka, Tongge Yu, and Angelica Zhang.

Source:

Massachusetts Institute of Technology MIT News