Case-encapsulated triboelectric nanogenerator for harvesting energy from reciprocating sliding motion

Reciprocating motion is a widely existing form of mechanical motion in natural environment. In this work we reported a case-encapsulated triboelectric nanogenerator (cTENG) based on sliding electrification to convert reciprocating motion into electric energy. Patterned with multiple sets of grating electrodes and lubricated with polytetrafluoroethylene (PTFE) nanoparticles, the cTENG exported an average effective output power of 12.2 mW over 140 kω external load at a sliding velocity of 1 m/s, in corresponding to a power density of 1.36 W/m². The sliding motion can be induced by direct-applied forces as well as inertia forces, enabling the applicability of the cTENG in addressing ambient vibration motions that feature large amplitude and low frequency. The cTENG was demonstrated to effectively harvest energy from human body motions and wavy water surface, indicating promising prospects of the cTENG in applications such as portable and stand-alone self-powered electronics.