Two recent research projects from the Hybrid Body Lab (HBL), directed by Cindy Hsin-Liu Kao, assistant professor of human centered design, are providing new opportunities in the field of human-computer interaction and for makers of electronic-textiles (e-textiles).

BioWeave

As soaring temperatures become a summer mainstay, we all contend with unwanted sweat. But what if we could easily and fashionably get medical information as we perspire? That’s the promise of BioWeave, a woven e-textile that absorbs and analyzes sweat.

Biological fluids like sweat, tears and other discharge are often considered a nuisance that textiles should absorb or allow to evaporate. But sweat contains hundreds of chemicals that provide information about what is happening beneath our skin, from immune system and stress responses to electrolyte balance and glucose levels. BioWeave provides a comfortable, non-invasive way to monitor health conditions.

“I see this work as examining new design opportunities with biofluids,” said Kao. “BioWeave merges woven textile design with bio-fluid detection as a step towards inexpensive, personalized and body-conformable health sensing.”

Jingwen Zhu, a Human Centered Design doctoral student and Hybrid Body Lab member, is lead author of “BioWeave: Weaving Thread-Based Sweat-Sensing On-Skin Interfaces,” which was presented at the Association for Computing Machinery’s 2023 conference on user interface and software technology. 

To create BioWeave, the Hybrid Body Lab team dyed weaving yarn with commercially available colorimetric test strips, which use colored compounds to indicate the concentration of particular chemicals. The result is color-changing woven sensors that are both functional and aesthetically pleasing. Imagine a competitive rower wearing a headband in team colors. As she sweats, the changing colors reveal she’s depleted her magnesium and potassium electrolytes.

The team also designed a series of thread-based electrochemical sensors that sense, analyze and send notifications to a device like a smartwatch or LED. Three-dimensional woven textiles are optimal for this technology, which is necessary for higher-level forms of analysis such as glucose monitoring.

Both methods benefit from novel 3D weaving techniques designed for comfort, absorption and the body’s movement. The team focused on areas where sweat glands are most abundant such as the armpit, hairline and between the toes, locations that are also under-explored because of their unique anatomy. Because humans sweat differently, BioWeave is easily customizable for individual bodies and user preference for placement. The woven structures can stand alone, connect to the body with fabric tape or integrate into a larger garment. 

Previous materials science research has focused on sweat absorption. In this work, the HBL team took a more human-centered approach, focusing on user experience and design opportunities with the woven textile structures. To understand usability, Zhu also designed a novel protocol for monitoring how participants feel while wearing the swatches during vigorous exercise.

“We value novel technology, and we prioritize human factors as critical to design,” said Zhu. “It is important to us that our users are comfortable and that they would actually use the wearable device.”

EcoThreads

From rapid prototyping, a new idea emerges. Engineering a new design requires repeated sampling. The biproduct of this innovation is often waste. But what if prototype swatches could be tossed into the compost bucket instead of thrown away? EcoThreads are biodegradable conductive threads designed by the multidisciplinary HBL team to manufacture textiles that do not require a long lifespan.

“E-textiles are comprised of the two biggest industrial polluters—electronics and fashion,” said Kao. “We want people to rethink their material choices. Too often we optimize for performance, but there are also times when sustainability must take precedence.” E-textiles are projected to reach a market size of $1.3 billion in the next 8 years. The prototyping phase—when designers ideating and exploring how threads, yarns and structures interact—provides an opportunity to think about textiles more transiently.

“EcoThreads: Prototyping Biodegradable E-textiles Through Thread-based Fabrication,” was presented by the lead author Jingwen Zhu at the Association for Computing Machinery’s 2024 conference on Human Factors in Computing Systems and received special recognition for sustainable practices as runner up.

The team explored two thread-based fabrication methods: wet spinning and thread coating to make functional threads that are both biodegradable and conductive. Because wet spinning is usually an industrial practice, they also built a wet spinning tool from a modified DIY syringe pump to design a process for the home creator. The conductive threads can be embroidered, braided or crafted like any thread or yarn, and when the textile is no longer usable, it is fully biodegradable or compostable based on thread type.

“By making sustainable materials more accessible, we are broadening access to sustainable practices,” said Zhu. “It is a priority to present projects that are accessible and not confined to a research lab setting.”

After designing the conductive threads, Zhu led a user study with e-textile practitioners. They were given two and a half hours to incorporate EcoThreads into their practice. User-generated ideas included a crochet stretch sensor for posture sensing and a woven decomposable picnic blanket that changes color with the pH of the food. One practitioner plans to fabricate swatches for use in her e-textile workshops.

Tronud TC2 Jacquard Loom

Both projects benefitted from the use of the Tronud TC2 digital jacquard weaving loom installed in 2023. A traditional loom requires lengthy set up of the vertical warp threads, but the TC2 can digitally change both warp and weft fibers. Digitization allows for more ideation and rapid prototyping as designers explore “what ifs.” Since expanding into digital weaving, the HBL team has connected to the digital weaving community, providing new opportunities for partnerships and innovation.

“My dissertation explores weaving novel materials into textiles for human-computer interaction,” said Zhu. “As a Ph.D. student, using the TC2 has enhanced my research, opening new possibilities and digitally generating different designs. It really enhances the creative process.”

BioWeave and EcoThreads are supported by the National Science Foundation. EcoThreads is also supported by the College of Human Ecology Engaged Research Seed Grant and Cornell Atkinson Center for Sustainability Academic Venture Fund.

In September, the Hybrid Body Lab will host a community workshop in Manhattan featuring EcoThreads as part of New York Textile Month.