New Stretchable Fabric Converts Motion Energy Into Electricity

Scientists from Nanyang Technical University (NTU) Singapore have developed a stretchable, waterproof fabric that converts motion energy into electricity. The fabric was developed using a polymer that converts mechanical energy into electricity when pressed or squeezed. Moreover, it incorporates spandex and a rubber-like material, making it flexible and washable without degradation. According to the team, proof-of-concept tests showed that a 3cm x 4cm piece of the fabric could power 100 LEDs and maintain a stable output of power for five months.

"There have been many attempts to develop fabric or garments that can harvest energy from movement, but a big challenge has been to develop something that does not degrade in function after being washed, and at the same time retains excellent electrical output," stated Associate Provost Professor Lee Pooi See. "In our study, we demonstrated that our prototype continues to function well after washing and crumpling. We think it could be woven into t-shirts or integrated into soles of shoes to collect energy from the body's smallest movements, piping electricity to mobile devices."

At its base, the fabric is an energy-harvesting device that converts vibrations from motion into electrical energy. It does this in two ways - when it's pressed or squeezed (piezoelectricity) and when it comes into contact or is in friction with other materials, such as skin or rubber gloves (triboelectric effect). To produce the fabric, the scientists created a stretchable electrode by screen-printing a metallic ink comprised of silver and styrene-ethylene-butylene-styrene (SEBS), a rubber-like material found in baby teething toys and handlebar grips, to make it more stretchable and waterproof. The stretchable electrode was then attached to a piece of nanofiber fabric that's comprised of two main components: poly(vinylidene/fluoride)-co-hexafluoropropylene (PVDFHPF), a polymer that produces an electrical charge when compressed, bent, or stretched; and lead-free perovskites, a material (calcium titanium oxide) found in solar cells and LEDs.

According to the scientists, the resulting fabric can generate 2.34 W per square meter of electricity, or enough to power small electronic devices. The researchers are currently looking at ways to harvest other forms of energy using their new fabric.