Ultrahigh piezoelectric performances in soft lead zirconate titanate/polydimethylsiloxane composites by ethanol-assisted freeze casting.

Abstract

Flexible materials capable of transducing mechanical signals into electrical responses underpin advances in wearable systems, soft robotics, and underwater sensing technologies. Ceramic-polymer piezoelectric composites can combine high electromechanical activity with mechanical compliance, but controlling phase distribution and architecture remains challenging. Here, we report an ethanol-assisted freeze-casting strategy that endows soft lead zirconate titanate/polydimethylsiloxane composites with an anisotropic architecture, enabling both high piezoelectric performance and excellent mechanical deformability. The composites achieve a high piezoelectric charge coefficient of 275 pC·N^-1, a piezoelectric voltage coefficient of 233 mV·m·N^-1, and an energy-harvesting figure of merit of 64.1 pm²·N^-1. The composites also exhibit robust mechanical flexibility, sustaining bending with radii below 5 mm, twisting, compressive deformation, and tensile strains up to 60%. The ethanol-assisted route suppresses freeze-induced cracking and improves three-dimensional compositional uniformity. This method offers a scalable and practical route for fabricating high-performance flexible piezoelectric composites for next-generation sensing technologies.