Inspired by the Chinese and Japanese arts of paper-cutting, scientists have developed a light-weight, paper-based device that can harvest energy from body movements to power sensors and watches.
Despite the many advances in portable electronic devices, one thing remains constant - the need to plug them into a wall socket to recharge.
Portable electronic devices, such as watches, hearing aids and heart monitors, often require only a little energy. They usually get that power from conventional rechargeable batteries.
Researchers from Georgia Institute of Technology in the US and Chongqing University in China wanted to see if they could untether small energy needs from the wall socket by harvesting energy from a user's body movements.
They have been working on this approach in recent years, creating triboelectric nanogenerators (TENGs) that can harness the mechanical energy all around us, such as that created by our footsteps, and then use it to power portable electronics.
However, most TENG devices take several hours to charge small electronics, such as a sensor, and they are made of acrylic, which is heavy.
Researchers turned to an ultra-light, rhombic paper-cut design a few inches long and covered it with different materials to turn it into a power unit.
The four outer sides, made of gold- and graphite-coated sand paper, comprised the device's energy-storing supercapacitor element.
The inner surfaces, made of paper and coated in gold and a fluorinated ethylene propylene film, comprised the TENG energy harvester.
Pressing and releasing it over just a few minutes charged the device to 1 volt, which was enough to power a remote control, temperature sensor or a watch, researchers said.
The research was published in the journal ACS Nano.