Sustainable highly charged C 60 -functionalized polyimide in a non-contact mode triboelectric nanogenerator

In this paper, we report on a new dielectric, a C 60 -containing block polyimide (PI- b -C 60 ). This was realized by introducing C 60 as pendent groups into a polymer backbone. When this dielectric was used in a non-contact mode triboelectric nanogenerator (TENG), it achieved high output power and reliable operation. Compared with perfluoroalkoxy alkane film-based TENGs, the TENG based on PI- b -C 60 generated 4.3 times higher output power and a superior charge density of over 300 μC m −2 with a 3 times slower charge decay rate. These results are most likely due to the excellent charge-retention characteristics induced by the most negative electrostatic potential of C 60 within the backbone, and these characteristics were confirmed by surface potential measurements. Furthermore, in the course of our work, two non-contact mode applications, a keyless electronic door lock system and a speed sensor with a tone wheel for a car, were developed. Without an ion injection process being needed, very sensitive and reliable operations of the speed sensor were successfully demonstrated, even under very humid conditions (∼99% RH).