SEOUL, June 18 (AJP) - Wearable health monitors, artificial skin, and soft robots require sensors that can stretch naturally with human movement without needing constant battery replacements. To meet this need, researchers in South Korea have created a self-powered sensor that generates its own electricity and can stretch up to 668 percent without losing performance, the Korea Advanced Institute of Science and Technology said Thursday.
Conventional stretchable sensors often rely on materials that create electricity when pressed or bent, but older fiber-based versions easily broke or lost signal strength when repeatedly stretched. While twisting fibers into coils helped them stretch further, it made their electrical output highly unstable because the internal layers would separate. The newly designed sensor solves this by interlocking tiny elastic particles inside the fibers, acting like microscopic hook-and-loop fasteners to maintain shape and electrical connection even under extreme stress.
The Korea Advanced Institute of Science and Technology (KAIST) said that the research team was led by Professor Kim Mi-so at the KAIST Department of Mechanical Engineering. The foundational study for this technology was published in the scientific journal ACS Nano on March 10, 2026.
To ensure the sensor could handle severe physical stress, the researchers engineered a seamless boundary between the layer that generates electricity and the layer that collects the signal. When applied to a coiled structure, the device maintained a stable electrical output even when stretched to 6.7 times its original length. The team also tested the sensor by tying it into knots, confirming it continued to work reliably despite continuous pressure and sudden impacts.
The researchers then combined the sensor with artificial intelligence to analyze the generated electrical signals. The system accurately distinguished between different types of movements, such as pressing, bending, and stretching. This makes the technology suitable for continuously tracking vital signs like heart rates and breathing, or powering the sensory network of soft robotics.
"The key achievement of this research is simultaneously securing mechanical resilience and electrical reliability by combining fiber structure design with electrode interface engineering," Professor Kim said. "We expect it to be applied to wearable medical devices requiring long-term wear, electronic skin, and sensory sensors for soft robots, enabling more accurate and continuous biosignal monitoring."
(Reference Information)
Journal/Source: ACS Nano
Title: Mechanically and Functionally Resilient Piezoelectric Fiber Coils and Knots for Reliable Self-Powered Sensing
Link/DOI: doi/10.1021/acsnano.5c19628
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