Stretchable Electret Energy Harvester Using The Fringe Field

In this report, a fringe-field-enhanced stretchable electret energy harvester for self-powered skin-attached wearable device has been proposed for the first time. Interdigitated electrode and electret are patterned on stretchable substrate, and the amount of induced charges by the fringe field is changed with the in-plane gap distance change between the electret and the electrode, leading to the external current. An early prototype has been developed with the MEMS process. Output power of tens of μW is expected at 1 Hz and 25% strain when a thin layer of high permittivity liquid is formed onto the surface.