Ultrahigh electrostrain in Pb-free piezoceramics: Effect of bending

TL;DR

This paper reveals that ultrahigh electrostrain in Pb-free piezoceramics is primarily caused by bending effects due to surface response differences, clarifying the mechanism behind the high strain.

Contribution

It demonstrates that bending, resulting from surface response disparities, is responsible for ultrahigh electrostrain in Pb-free piezoceramics, providing new insight into strain mechanisms.

Findings

Ultrahigh electrostrain (>1%) is linked to bending effects.

Surface response differences cause bending in the piezoceramic disc.

Bending leads to the ultrahigh strain observed.

Abstract

Recently several reports showing ultra-high electrostrain (> 1 %) have appeared in Pb-free piezoceramics. However, there is lack of clarity on the nature of the ultrahigh strain. Here, we demonsrate that the ultrahigh strain is a consequence of bending of the disc. We show that the propensity for bending arises from the difference in the response magnitude of the grains at the positive and negative surfaces of the piezoceramic when the field is applied.