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 0.7 Sr 0.3 MnO 3 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.