Scientists at the Sungkyunkwan University, South Korea have created a double-layered fabric out of silver-coated woven textile that can charge the battery of a mobile phone.
The foldable patch of fabric wrapped around your wrist can gather enough energy from your arm movement.
The new fabric relies on the triboelectric effect, which occurs with certain materials become electrically charged after coming into fricative contact with a different material.
Electrons are transferred from one material to the other, causing one material to build up a positive charge, while the other gets a negative charge.
In a demonstration, researchers attached the generator on a jacket sleeve and embedded six LEDs, a small liquid-crystal display and a keyless car remote control in the jacket.
When the wearer moved his arms or wrist, the fabric turned each gadget on one at a time.
The researchers are testing more materials for the generator that could potentially yield even more power.