Fig. 5: Demonstrations of thermoelectric power generation by harvesting thermal energy from the environment and human body, respectively.

a Exploded schematic diagram of a solar thermal/thermoelectric/radiative cooling (STR) hybrid device. b Schematic diagram of the preparation process of a STR hybrid device. c Schematic diagram and corresponding optical photograph. Power generation performance of a STR hybrid device: d During daytime; e At night. f Photograph of generating electricity using the temperature difference between the wrist and the environment. A fully inkjet-printed Ag₂Se-based flexible device consisting of 150 Ag₂Se legs is used for the demonstration. Schematic diagram of thermoelectric power generation utilizing body heat: g top view; h side view. i Electricity obtained by using body heat.