Push-Button Energy Harvester with Ultra-Soft All-Polymer Piezoelectret

Abstract

Piezoelectrets are porous space-charged polymers with high piezoelectric coefficients and excellent softness. They have found applications in making vibrational or kinetic energy harvesters, acoustic sensors and so on. In the present study, an all-polymer multilayer piezoelectret made from thin parylene-C membranes, high-performance dip-coated CYTOP electrets and flexible PEDOT:PSS electrodes is micro-fabricated for push-button energy harvester. To avoid electret discharge, mesh-like spacers are formed in each layer. The piezoelectret is charged with soft X-ray to its critical voltage for air breakdown. Up to 41 μJ electrical energy has been generated with the 8-layer prototype at a pushing force of only 1 N. Its piezoelectric coefficient d33 reaches 125 nC/N and its energy density is 62 μJ/cm3/N, which is much higher than that of commercialized push-button energy harvesters.