Scientists at Nanyang Technological University in Singapore have developed a flexible, waterproof “cloth” capable of converting body movement into electrical energy to power wearable devices.
The most important ingredient, according to NTU Singapore(Opens in a new window), is a polymer that, when pressed or squeezed, converts the vibrations generated by the slightest movement into an electrical charge. In a proof-of-concept experiment, researchers found that tapping a 4 cm long piece of the material — made with a spandex base layer and reinforced with a rubber-like component — generated enough electrical energy to light up 100 LED light bulbs bring to.
Power dressing — the concept of a sweater that doubles as a flashlight or a pair of jeans that charges your phone — has been analyzed for more than two decades. However, most electricity-generating fabrics do not stand up to prolonged use, especially when repeatedly cleaned in the washing machine.
“There have been many attempts to develop fabrics or garments that can harvest energy from movement, but a major challenge has been to develop something that does not degrade in function after washing while maintaining excellent electrical performance,” said the Study leader and NTU Associate Provost Professor Lee Pooi See said in a statement.
That’s no problem for NTU Singapore’s fabric, which holds up through washing, folding and crumpling. The team estimates that their fabric can maintain stable electrical performance for up to five months, underscoring its potential as a smart textile or portable power source.
“We showed that our prototype continued to perform well after being washed and crumpled,” Lee explained, adding that it “could be woven into T-shirts or incorporated into shoe soles to collect energy from the body’s smallest movements and stream to mobile devices.”
The prototype generates a charge of 2.34 watts per square meter in two ways: when it is pressed or squeezed (piezoelectricity) or when it comes into contact with other materials such as skin or rubber gloves or creates friction (triboelectric effect). Attach it to an arm, leg, hand, elbow or even a shoe insole and the textile can harness energy from a range of human movements such as running or sports.
Recommended by our editors
“Despite improved battery capacity and reduced power requirements, power sources for portable devices still require frequent battery replacements,” Lee said. “Our results show that our energy-harvesting prototype fabric can harness a human’s vibrational energy to potentially extend the life of a battery or even build self-sufficient systems.”
The results(Opens in a new window) were published in the magazine in April Advanced Materials.
Get our best stories!
Sign up for What’s new now to get our headlines delivered to your inbox every morning.