TEGs for energy harvesting in MESOC. (a) TE phenomenon in n-type and p-type materials and the working principle of thermoelectric devices [54]. Copyright©2021, Royal Society of Chemistry. (b) The schematic diagram of a TE module consists of p- and n-type legs [79]. Copyright©2020, Elsevier. (c) The voltage generated by the body temperature, by collecting the body temperature to power the LED [93]. Copyright©2023, Elsevier. (d) Pyroelectricity of lead sulfide quantum dot films induced by Janus-ligand shells [95]. Copyright©2021, American Chemical Society. (e) Schematic diagram of the complete heat transfer process of a wearable thermoelectric device [97]. Copyright©2021, Elsevier. (f) Novel wearable pyrothermoelectric hybrid generator for solar energy harvesting [98]. Copyright©2022, American Chemical Society.