Mechanical-thermal hybrid rotational nanogenerator applied for self-powered sensing node

Abstract

Thermal energy is an attractive and sustainable power source for supporting low-power-consumption sensing nodes and microsystems in the Internet of Things (IoT). Most studies on thermal energy scavenging are based on the Seebeck effect, however, the output of thermoelectric generators (ThEGs) is relatively low under small temperature differences. Herein, we propose a mechanical-thermal hybrid rotational nanogenerator that not only reutilizes waste heat energy and captures rotational mechanical energy but also enables active detection of rotation speed and temperature. An unpowered hood facilitates the transmission of waste heat energy into rotational mechanical energy. At the same time, an annular-structure thermoelectric generator (AS-ThEG) is integrated into a relative-sliding triboelectric nanogenerator (RS-TENG). The power densities of the triboelectric and thermoelectric components are 42.88 mW/m² and 51.16 mW/m², respectively. Furthermore, the voltage signal of the RS-TENG enables velocity sensing, and the resistance variation of the AS-ThEG provides information on temperature changes. Additionally, it has been demonstrated that the mechanical-thermal hybrid rotational nanogenerator can be installed at ventilation and heat dissipation ports to harvest energy from the surrounding environment. This study presents a technology for harvesting mechanical and thermal energy, offering significant potential for industrial waste heat recovery applications.