Triboelectric motion sensor combined with electromagnetic induction energy harvester

Abstract

We investigate the possibility of combining electromagnetic induction and triboelectricity for creating a low-friction floating magnet-based sensor system to detect motion and harvest energy from small vibrations or oscillatory magnetic fields. We designed a system with low friction such that the energy harvester based on electromagnetic induction is not influenced by the triboelectric transduction mechanism. An enclosed system combining a triboelectric and electromagnetic mechanism which responds to vibrations or changes in magnetic fields was designed. The system comprises an aluminum-covered magnet placed inside a tube covered by metallized fluorinated ethylene propylene. The sliding action between the metal and the polymer causes triboelectric charging. The magnet acts as a carrier for the aluminum surface, but is also used to induce a voltage in a copper coil, thus allowing one to detect the same mechanical motion utilizing two different technological principles. The main advantage of our design is an enhanced sensing mechanism based on the triboelectrical signal that does not require one to interpret the complicated electromagnetically induced signal that may occur for complex magnet geometries.