A flexible and lead-free BCZT thin film nanogenerator for biocompatible energy harvesting

Abstract

High-performance piezoelectric thin films generally contain toxic lead that limits the application scenarios especially in wearable and medical devices. Alternative lead-free piezoelectric materials such as Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃ (BCZT) have been proved to have high biocompatibility and competitive piezoelectric performances. However, few have reported BCZT thin films integrated within flexible electronics. To fill this gap, we prepare BCZT thin films on flexible mica substrates and based on that fabricate piezoelectric nanogenerators (PENGs). The piezoelectric modulus d₃₃ of the BCZT thin films evaluated from the established system reaches 150 pC N⁻¹, which is comparable to those of films grown on single crystal substrates. The BCZT-based PENG can charge capacitors under mechanical excitation, indicating that it has broad application prospects in the field of flexible self-powered electronics.