Wearable electrode-free triboelectric generator for harvesting biomechanical energy.

In this article, we present an electrode-free triboelectric generator for harvesting biomechanical energy from human motions through triboelectrification between shoe sole and ground. A thin film of porous ethylene-vinyl acetate copolymer (EVA) is designed and pasted on shoe sole to serve as the friction surface. Electricity is generated by the contacting friction of shoe sole with ground surface during walking, which makes no initial vertical gap needed in shoe sole. At the same time, human body is employed as the natural electrode instead of fabricated electrodes, and the electricity can be obtained from any part of human body. In addition, output performances are characterized by using three different conductors as reference electrode. The output voltage of 810 V is achieved and charge of over 550 nC is transferred in one step of an adult׳s walking. Meanwhile, 76 blue LEDs are lighted through a watch as output node. Owing to the advantage of body electrode, it has potential applications in wearable electronics and implantable devices. [ABSTRACT FROM AUTHOR]