Bubble Electret-Elastomer Piezoelectric Transducer

Abstract

Ferroelectret-based piezoelectric transducers are, nowadays, commonly used in energy harvesting applications due to their high piezoelectric activity. Unfortunately, the processing properties of such materials are limited, and new solutions are sought. This paper presents a new solution of a piezoelectric transducer containing electret bubbles immersed in an elastomer matrix. Application of a gas-filled dielectric bubble as the fundamental cell of the piezo-active structure is discussed. A simplified model of the structure, containing electret thin-wall bubbles and elastomer dielectric filling, was applied to determine the value of the piezoelectric coefficient, d33. An exemplary structure containing piezo-active bubbles, made of an electret material, immersed in an elastomer filling is presented. The influence of the mechanical and electrical properties of particular components on the structure piezoelectric properties are experimentally examined and confirmed. The quasi-static method was used to measure the piezoelectric coefficient, d33. The separation of requirements related to the mechanical and electrical properties of the transducer is discussed.