Hybrid Triboelectric-Electromagnetic Human Energy Harvester Based on an Eccentric Rotor

With increasing multifunctional requirements for wearable electronic devices, higher requirements have been placed on the battery life of such devices. Humans generate a large amount of mechanical energy in daily life; efficiently converting this mechanical energy into electrical power to drive sensors is an important approach to addressing the issue of limited battery life. In this study, a hybrid energy harvester combining a triboelectric nanogenerator (TENG) and an electromagnetic generator (EMG) was developed to collect human limb motion energy and provide continuous power for wearable devices and sensors. The WH-HG (triboelectric-electromagnetic hybrid generator) consists of a central eccentric rotor, copper coils at the top and bottom, and a TENG section at the top. When driven by human limb movement, the eccentric rotor rotates. In the EMG unit, the rotation of the magnets inside the rotor changes the magnetic flux through the surrounding coils, generating electric energy via electromagnetic induction. In the TENG unit, rotation of the eccentric rotor drives periodic contact and separation between polycarbonate (PC) villi and a fluorinated ethylene propylene (FEP) film, producing electrical energy through triboelectrification and electrostatic induction effects. When the energy harvester was worn on a tester's wrist and tested at a running speed of 160 steps per minute, the WH-HG generated 10.61 mW, which was sufficient to light up over 100 LEDs and, after energy storage in capacitors, power a temperature-humidity sensor and a calculator. This research promotes the advancement of human-motion energy harvesting and provides an important reference for further efficient harvesting of human motion energy.