Apparel / Textiles & Accessories

A new type of fiber developed by researchers at MIT and Sweden can be made into clothes, which can sense the degree to which it is stretched or compressed, and then provide instant tactile feedback in the form of pressure, lateral stretch or vibration. The team suggests that such fabrics can be used to help train singers or athletes to better control breathing clothing, or to help patients recover from illness or surgery to restore breathing patterns.

The multilayer fiber contains a fluid channel in the center, which can be activated by the fluid system. The system controls the geometry of the fiber by pressurizing and releasing a fluid medium (such as compressed air or water) into the channel, so that the fiber acts as an artificial muscle. The fiber also contains a stretchable sensor that can detect and measure the degree of stretch of the fiber. The resulting composite fibers are thin and flexible enough to be sewn, woven or knitted using standard commercial machines.

This fiber, called OmniFibers, will be presented at the Computer Association's User Interface Software and Technology Online Conference this week.

The new optical fiber architecture has many key features. Its extremely narrow size and the use of inexpensive materials make it relatively easy to construct fibers into various fabric forms. It is also compatible with human skin because its outer layer is based on a material similar to ordinary polyester. Moreover, its fast response time and the strength and diversity of the power it can transmit allow a fast feedback system that uses the sense of touch (based on the sense of touch) for training or remote communication.

Afsar said that the disadvantage of most existing artificial muscle fibers is that they are either heat-activated and cause overheating when in contact with human skin, or they are inefficient or cumbersome during training. She said these systems often have slow response and recovery times, limiting their direct usability in applications that require fast feedback.

As an initial test application of the material, the team created a kind of underwear that singers can wear to monitor and replay the movement of respiratory muscles, and then provide kinesthetic feedback through the same piece of clothing to encourage the best posture and breathing pattern to achieve the desired Vocal performance. "Singing is very close to home because my mother is an opera singer. She is a soprano," she said. During the design and production of this dress, Afsar worked closely with classically trained opera singer Kelsey Cotton.

"I really want to capture this expertise in a tangible form," Afsar said. The researchers asked the singer to perform while wearing a garment made of their robotic fibers and recorded movement data from strain sensors woven in the garment. Then, they convert the sensor data into corresponding tactile feedback. "We are finally able to achieve the sensing and driving patterns we want in textiles, recording and replaying the complex movements we can capture from the physiology of professional singers, and transforming them into the body of a non-singer, a novice learner . Therefore, we not only get this knowledge from experts, but we are also able to pass it on to those who have just learned," she said.

Although this preliminary test is conducted in the context of vocal education, the same method can be used to help athletes learn how to best control their breathing in a given situation, based on monitoring athletes who complete various activities and stimulate muscle groups Afsar said these are all at work. Ultimately, it is hoped that these garments can also be used to help patients restore healthy breathing patterns after major operations or respiratory diseases such as Covid-19, and even as an alternative therapy for sleep apnea (Afsar suffered from this disease when she was a child, she said).

The system can also be used to train other types of muscle movements besides breathing. For example, "Many of our artists have learned amazing calligraphy, but I want to feel the dynamics of brushstrokes", which may be done with sleeves and gloves made of this closed-loop feedback material. He suggested that Olympic athletes can improve their skills by wearing clothing that mimics the movements of top athletes, whether they are weightlifters or skiers.

This yarn-like soft fiber composite has five layers: the innermost fluid channel, a silicone-based elastic tube containing a working fluid, a flexible stretchable sensor that can detect changes in strain and resistance, and a woven polymer control fiber A stretchable outer mesh of outer dimensions, and a non-stretched filament that provides mechanical restraint to the overall ductility.

"Fiber-level engineering and fabric-level design are well combined in this research," said Li Ning, assistant professor of human-computer interaction at Carnegie Mellon University, who has nothing to do with this research. She said the work demonstrated "different machine knitting techniques, including inlay and active spacer fabrics, advancing the most advanced technology for embedding drive fibers into textiles." "When we talk about the interaction of wearable devices with driving fabrics, integrated strain sensing and feedback are essential."

Afsar plans to continue working to make the entire system (including its control electronics and compressed air supply) more compact to make it as unobtrusive as possible, and to develop a manufacturing system to be able to produce longer filaments. In the next few months, she plans to start experimenting with the system to transfer skills from experts to novice singers, and then explore different types of movement exercises, including choreographers and dancer movements.

It is worth mentioning that clothing made of this fiber is sensitive and can withstand a variety of strengths to form a fast feedback system. In the future, it may also be used for training or tactile-based remote communication.