Recent progress in human body energy harvesting for smart bioelectronic system

Abstract From every heartbeat to every footstep, human beings dissipate energy all the time. Researchers are trying to harvest energy from the human body and convert it into electricity, which can be supplied to electronic medical devices closely related to human health. Such an energy recycling form is currently a research hotspot in the fields of energy harvesting and bioelectronics. This review firstly summarizes the distribution and characteristics of three primary energy sources contained in the human body, including thermal energy, chemical energy, and mechanical energy. Afterwards, the applicable energy harvesting technologies and corresponding working mechanisms for different energy sources are introduced. Some typical demos and practical applications of each type of human body energy harvesting technology are also presented. Specifically, the advantages and critical issues of different energy harvesting technologies are summarized, and corresponding promising solutions are also provided. Besides, the interaction strategies between various energy harvesting devices and the human body are summarized from the aspects of wearable and implantable applications. Finally, the concept of a self-powered closed-loop bioelectronic system (SCBS) is put forward for the first time, which organically combines portable electronic devices, implantable electronic medical devices, energy harvesting devices, and the human body. The prospect of symbiosis between the SCBS and the human body is provided. The demands and future development trends of the SCBS are also discussed.