Figure 7.

Wearable piezoelectric nanogenerators based on nanosheets

(i) Photographs together with voltage output produced through human motions for (a) wrist bending, (b) finger tapping, together with foot stepping by (c) heel as well as (d) toe (Shi et al., 2018a).

(ii) (a) Voltage output of four nanogenerators connected in series, (b)–(d) photog of the experiments of foot pressure, bending, muscle stretching, respectively, for the nanogenerator in real time (Manjula et al., 2020).

(iii) (a) Wearable PENG deposited at the wrist joint and its corresponding output signal. 10 (b) Wearable PENG attached onto finger joint and its electrical output signal (Rafique et al., 2021).

(iv) Current output signal (a) while the page turning forward and (b) turning back. (c-d) The ability of the LCD screen to connect with the PENGs while turning the page. (e) After releasing or bending for 10,000 cycles, the current output remains stable. The inset image illustrates the break strength of the V-ZnO/BC film compared with the print paper as well as the regenerated BC paper (Zhang et al., 2018a).