Triboelectric Nanogenerator: Single-Electrode Mode

The two modes presented in Chap. 2 and 3 require that the two electrodes must be interconnected. In practice, if one part of the contact media is a freely moving object, such as a moving vehicle or a walking person, there is no way to connect a lead to the vehicle or the person. To meet this challenge, two new modes have been introduced to overcome this drawback: including single-electrode TENGs (SETENGs)Single-electrode TENG (SETENG) (Yang et al. Adv Mater 25(45): 6594–6601 2013 [1]) and freestanding-triboelectric-layer nanogenerators (FTENGs)Freestanding-triboelectric-layer nanogenerator (FTENG) . In this chapter, we will mainly discuss the single-electrode TENGs. Single-electrode TENGs have similar working mechanism of contact electrification. However, in this structure, only one electrode is attached to (or serves as) the triboelectric layer. The other electrode serves as an electric potential reference and can be placed anywhere in the space, even directly be the ground. In this regard, the moving part of the TENG is not connected with any electrode, which substantially simplifies the device fabrication process and improves the operation convenience. On the other hand, a major drawback is that the overall output performance will be lower due to the electrostatic shield effect of the primary electrode, but it is a good approach for touch sensors. The theory, working mechanism and the potential applications of this mode will be systematically introduced.