All-Polymer Soft-X-Ray-Charged Piezoelectret for Push-Button Energy Harvester

Piezoelectret using space-charged porous polymers attracts much attention due to its high piezoelectric coefficient. In the present study, a novel all-polymer soft-X-ray-charged multilayer piezoelectret is proposed for push-button energy harvesting. The prototype is microfabricated using a parylene-C structural layer with patterned gap-control protrusions, dip-coated PEDOT:PSS electrode, and a dip-coated polymer electret layer. With the current prototype, up to 24.6 µJ electrical energy has been obtained with a single pushing force of only 1.3 N, corresponding to a record-high piezoelectric coefficient d33 of 105 nC/N, 30 times higher than conventional MEMS-based piezoelectrets.