Fig. 11.

a–d The structure and working principle of the tribo-, pyro-, and piezoelectric hybrid cell. e The circuit that hybridizes TENG and PPENG outputs. f The LED was lighted by the hybridized output current. g The schematic diagram of the structure used to demonstrate the temperature sensing. h The voltage and the temperature variation of the PPENG. i The schematic diagram of the measurement setup. j A force of approximately 0.5 N applied to the surface. Adapted with permission from ref. 56. Copyright 2015 John Wiley and Sons