An unmovable single-layer triboloelectric generator driven by sliding friction

In this paper we present a flexible single layer triboelectric generator (S-TEG). The device consists of two fixed intedigital electrodes on the top and bottom surfaces of a polyimide substrate. In operation, the S-TEG is a fixed surface. Electricity is generated by sliding friction with external objects. In comparison to traditional TEGs with movable electrodes, the fixed electrodes on S-TEG simplify packaging process. Charges of hundreds nC can be generated by a rod sliding on the S-TEG. Due to the interdigitated shape of the electrodes energy harvesting is still possible regardless of the material of the scratching rod. Various materials can be utilized to generate electricity free of the limitation of triboelectric properties, which greatly broadens the S-TEG's application field. In addition, the output voltage can be greatly enhanced by using the slippage of two S-TEGs. When one S-TEG slides on another, the maximum peak output voltage can reach 342.8 V and more than 1000 nC charges are transferred in each sliding cycle. Owing to the simple fabrication process, S-TEG devices using this structure are suitable for mass production. A demonstration was conducted to illustrate the potential of this S-TEG device to harvest energy from sliding surfaces encountered in daily life. An S-TEG integrated in a computer mouse pad can sufficiently drive 20 LEDs and a LCD screen. (C) 2014 Published by Elsevier Ltd.