High-Performance Ultrasensitive Flexible Piezoelectric Thin Film Sensors via a Cost-Effective Transfer Strategy

Abstract

Currently, reported physical or chemical methods to produce flexible perovskite thin films rely on the use of expensive single crystal substrates or large-scale precision equipment. Here, a high-performance ultrasensitive piezoelectric sensor via a cost-effective strategy is developed to enable the release of lead zirconate titanate (PZT) thin films from an inexpensive mica substrate, which are subsequently transferred to a flexible polyethylene terephthalate substrate. The weak van der Waals interaction between the mica/La_0.7Sr_0.3MnO₃ heterostructures minimizes mechanical clamping effects and provides favorable lattice and thermal matching conditions for the growth of high-quality thin films. The transferred thin films exhibit significantly improved mechanical and functional properties, including an outstanding piezoelectric response (474.2 pm V⁻¹) and an excellent mechanical flexibility, with a bending radius up to 1 mm. The sensor formed via the new transfer strategy exhibits a highly sensitive response to wide-angle bending (110 mV degree⁻¹) and small pressure changes (1.8 V kPa⁻¹), and is successfully employed for real-time breathing monitoring and wireless gesture recognition, thereby demonstrating its significant potential in applications related to flexible electronics.