New Energy-Generating Cloth to Charge Your Phone as You Walk

A reveller uses his smart phone to take pictures during New Year's Eve celebrations in Times Square, New York December 31, 2014. REUTERS/Zoran Milich

Scientists have successfully tested energy-generating cloth that could be used to charge wearable technologies such as smart watches and personal electronics - meaning you could soon be charging your mobile phone as you walk.

The researchers say energy could be created from "everyday motion" - such as walking - using triboelectric nanogenerators (TNGs). These are layers of silicon-based organic material stacked on top of each other which, when rubbed together, create electrons. This energy can then be captured, and could be used to power electronic devices.

The findings were made by a team based at the Sungkyunkwan University in South Korea, and were published by the American Chemical Society.

The lead researcher Professor Sang-Woo Kim explains: "In principle, the surface charge is transferred when two materials with different triboelectric polarities are contacted/rubbed together; when they separate, a dipole moment is developed which drives electrons through external loads on the basis of both triboelectric and electrostatic effects."

The energy created in his team's experiment helped to self-power LED lights and a keyless vehicle entry system without the need for an external power source. According to Dr Kim, the research "proves potential applications of wearable triboelectric nanogenerators in self-powered smart cloths, health care monitoring and self-powering wearable devices, and even personal electronics, when a person who wears this energy harvesting cloth moves or walks around".

While flexible energy storage in clothes has previously been developed, this new cloth is a major step forward as it creates the energy it then stores, meaning it doesn't need an external power source.

Professor Kim says his team have been working with a global company, although he declined to say who, for the past two years as they make steps towards putting the technology to commercial use. However, he admits work still needs to be done on how the energy can be stored efficiently in textile platforms.

"The wearable triboelectric generation (WTNG) is one of the promising new energy harvesting methods with extremely high output voltage and efficiency, low cost, high versatility and simplicity in structural design and fabrication, stability and robustness", he adds, also pointing out that this kind of energy is environmentally friendly.