Soft Electret Gel for Low Frequency Vibrational Energy Harvesters

Abstract

A soft electret material was obtained by solidifying ionic liquid in a polymer network and immobilizing cations (+) on the surface. When a piece of soft electret gel is sandwiched between a pair of electrodes, a large amount of charge is induced in an electrical-double-layer capacitor (1.0-10 μF/cm2) appearing at the interface of the electrode and the ionic liquid gel without an external voltage source. By retracting the electrode repeatedly, we obtained a current output of a few μAp-p/cm2 stably.