Flexible piezoelectrics: integration of sensing, actuating and energy harvesting

Abstract

Piezoelectric materials are capable of converting between mechanical and electrical energy, and are suitable for sensing, actuating and energy harvesting. While most conventional piezoelectric materials are brittle solids, flexible piezoelectric materials (FPM) retain functionality even under bending and stretching conditions. This characteristic has garnered increasing attention in recent years, particularly for wearable devices, where the ability to adapt to dynamic human movements is essential. In addition, wearable devices also demand excellent conformability, durability, and adaptability to miniaturization. FPM emerge as a promising solution that meet all these requirements. This review thus aims to offer a comprehensive summary of recent advances in the field of FPM, including piezoelectric polymers, composites, and inorganic flexible films. We introduce and categorize the specific features of these materials and highlight their emerging applications in electronic devices, and comment on the prospect of FPM as well as their potential challenges.