New 'skin-based generators' can help smartphone charge its battery from your skin

A new research has revealed about a new flexible generator that converts muscle movements into enough power for small electronics, using human skin as one of its charge-collectors.

The postage-stamp-sized device takes advantage of static electricity to convert mechanical energy into electrical energy. Such friction-powered generators could usher new types of wearable sensors that don't require batteries but instead are powered by the wearer's daily activities like walking, talking or holding an object.

Researchers at the National University of Singapore demonstrated that the new device, which can generate 90 volts of open circuit voltage when touched gently with a finger, can be used as a wearable self-powered sensor to track the user's motion and activity.

This friction-inducing phenomenon, called the triboelectric effect, electrical charge builds up on two dissimilar surfaces when they're put in close contact. When they are pulled apart or flexed, a potential difference is generated and a current starts flowing between them that can be collected using an electrode.

Researcher Lokesh Dhakar said that skin, the most abundant surface on a human body, is a natural choice for one of the triboelectric layers and also skin as a triboelectric material has a high tendency to donate electrons or get positively charged which is important in improving the performance of the device if the other triboelectric layer intentionally chosen as the one with a tendency to get negatively charged.

Tapping the device generated the highest voltage of 90V and power of 0.8mW, Dhakar says. This could light up twelve commercial LEDs.