Via a method often known as electrospinning, researchers at Penn State weave new prospects for well being sensors that may be a part of clothes made with nanofiber supplies that generate electrical energy from the wearer’s movement to energy them. Credit: Jennifer M. McCann.
July 20, 2025
Editor’s notice: This article initially appeared on Penn State News.
By Jamie Oberdick
UNIVERSITY PARK, Pa. — Could clothes monitor an individual’s well being in actual time, as a result of the clothes itself is a self-powered sensor? A brand new materials created by means of electrospinning, which is a course of that attracts out fibers utilizing electrical energy, brings this chance one step nearer.
A group led by researchers at Penn State developed a brand new fabrication strategy that optimizes the inner construction of electrospun fibers to enhance their efficiency in digital purposes. They revealed their findings within the Journal of Applied Physics.
This novel electrospinning strategy might open the door to extra environment friendly, versatile and scalable electronics for wearable sensors, well being monitoring and sustainable vitality harvesting, in line with Guanchun Rui, a visiting postdoctoral pupil within the Department of Electrical Engineering and the Materials Research Institute and co-lead creator of the research.
The materials is predicated on poly(vinylidene fluoride-trifluoroethylene), or PVDF-TrFE, a light-weight, versatile polymer identified for its means to generate an electrical cost when pressed or bent. That high quality, known as piezoelectricity, makes it a robust candidate to be used in electronics that convert movement into vitality or indicators.
“PVDF-TrFE has strong ferroelectric, piezoelectric and pyroelectric properties,” Rui mentioned, explaining that like piezoelectricity, pyroelectricity can generate electrical expenses when temperature change and thus affect the fabric. “It’s thermally stable, lightweight and flexible, which makes it ideal for things like wearable electronics and energy harvesters.”
Electrospinning is a method that makes use of electrical drive to stretch a polymer answer into extraordinarily skinny fibers. As the fibers dry, the best way the polymer chains pack collectively determines their efficiency. The researchers hypothesized that altering the focus and molecular weight of the polymer answer might result in extra organized molecular buildings.
“Crystallinity means the molecules are more ordered,” Rui mentioned, noting that the group additionally theorized the construction might have increased polar part content material. “And when we talk about polar phase content, we mean that the positive and negative charges in the molecules are aligned in specific directions. That alignment is what allows the material to generate electricity from motion.”
The researchers defined that electrospinning performs a key position in enabling this alignment.
“The process stretches the fibers in a highly mobile state, which predisposes the polymer chains to crystallize into the form we want,” mentioned Patrick Mather, a co-author of the research and professor of chemical engineering and dean of the Schreyer Honors College. “You start with a liquid, and it dries over a split second as it travels to the collector. All the packing happens during that brief flight.”
One shocking discovery, Mather mentioned, got here from experimenting with unusually excessive concentrations of polymer within the answer.
“These were very high concentrations, roughly around 30%, and much higher than we typically use,” Mather mentioned. “My initial thought was that this isn’t going to work. But we were using a low molecular weight polymer, and that turned out to be essential. The chains were still mobile enough to pack well during crystallization. That was the biggest surprise. Sometimes, as scientists, we have doubts even when the theory says it should work. But Rui boldly proceeded, and it worked.”
The implications are important, in line with Mather. By enhancing the inner construction of the fibers with out requiring high-voltage remedy or complicated post-processing, the group created a cloth that might be each low-cost and scalable.
Rui famous that the fabric’s first supposed software was truly for face masks, with funding from the National Institutes of Health (NIH).
“When electrospun into a mask, the material holds a charge that can attract and trap bacteria or viruses,” Rui mentioned. “But it also has broader uses in sensors and energy harvesters. If you press it, it can generate electricity.”
Qiming Zhang, professor of electrical engineering and Harvey F. Brush Chair within the College of Engineering and co-lead creator of the research, added that the fabric’s cloth-like texture might make it extra comfy than conventional plastic-based sensors — it might even be instantly integrated into clothes.
“If you wear it like clothing, it’s much better,” he mentioned. “You could even incorporate sensors into bandages.”
Mather identified that electrospinning is effectively suited to producing massive sheets, which might be vital for energy-harvesting techniques. Currently, he notes, most sensors and actuators, materials that may change or deform through exterior stimuli, are small movies.
“Most sensors or actuators are small films,” he mentioned. “But this process could be scaled to wide-area sheets. The equipment exists, but we’d just need to pair it with an electrode manufacturing process.”
Looking forward, the researchers mentioned they see alternatives to additional enhance the fabric by means of post-processing. Right now, the electrospun sheets are about 70% porous. Applying warmth and stress might densify them and enhance sensitivity and output.
“We already have ideas about the next steps,” Mather mentioned. “One is densification. We could remove the air between fibers by compacting the sheets after electrospinning, which could boost their performance for certain applications.”
For broader adoption, the group mentioned industrial companions can be key.
“We need to find an industrial partner,” Mather mentioned. “Someone in the device space or energy harvesting who’s interested in taking this to the next level. In my experience, if something works early, it will work commercially. If it’s very delicate, it won’t hold up. This is a very robust system.”
Along with Rui, Mather and Zhang, different authors of the research are Wenyi Zhu, graduate analysis assistant in electrical engineering at Penn State; and Yongsheng Chen, Bo Li and Shihai Zhang, PolyK Technologies.
The U.S. National Institutes of Health and U.S. National Science Foundation supported this analysis.
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