Stretchable Fluorinated Electret for Skin-Attachable Energy Harvester

This paper presents a novel intrinsically stretchable fluorinated electret for enabling energy autonomy of skin electronics. With the support of quantum chemical analysis, we have successfully developed a stretchable electret by cross-linking perfluoroelastomer FFKM, which exhibits a record-high surface charge density of 0.74 mC/m
²
, as well as an almost linear stress-strain curve with maximum elongation reaching 220%. Notably, the surface potential exhibits remarkable stability even after 10
⁴
stretch cycles. We also propose and successfully fabricate an early prototype of the fringe-field-enhanced stretchable electret energy harvester that utilizes the developed stretchable electret.