Heat pipe-based electric generator for waste heat harvesting

Converting widespread waste heat into electricity in an efficient and low-cost way for significant performance is challenging. Here, we demonstrate a novel heat pipe -based electric generator (HPEG) utilizing internal interfacial movement for effective thermal energy harvesting and power supply. A giant thermal voltage (analogous to the Seebeck coefficient in thermoelectric) up to -0.68 V K-1 and an open -circuit voltage of -24 V are achieved in a gravity -assisted heat pipe constructed from a polytetrafluoroethylene (PTFE) tube at a low working temperature of 333 K. The dependence of output performance on the input power, electrode position, electrode length, working angle, solution concentration, inner pressure, and electrode diameter were systematically investigated. As a proof of concept, we demonstrate that the device can light up a light -emitting diode (LED) and power a commercial liquid crystal display (LCD). Overall, benefiting from its simple design and good heat -toelectricity performance, the HPEG is proven to be a promising approach for waste heat harvesting.