High-performance microcone-array flexible piezoelectric acoustic sensor based on multicomponent lead-free perovskite rods

Piezoelectric materials can serve as favorable candidates for future cochlear implants. However, most piezoelectric hearing devices until now have failed to simultaneously provide high sensitivity, desired flexibility, broad frequency selectivity, and biocompatibility. Herein, inspired by human outer ear hair cells, we meet these issues by introducing a microcone patterning array strategy based on novel lead-free, multicomponent rod-shaped niobate piezoelectric materials with a morphotropic phase boundary. The output voltage of the rod-based, flexible piezoelectric acoustic sensor (FPAS) is nearly 300% of that of the isotropic particles. The microcone patterning FPAS with stable performance in harsh environments shows high sensitivity (39.22 mV Pa−1⋅cm−2) due to the significant enhancement of sound energy absorption and can record sound signals, recognize audio signals, and realize human-computer interactions. Our work demonstrates that the FPAS holds promise for various applications, such as the Internet of Things (IoT), cochlea implants, wearable acoustic equipment, and human-computer interaction.