Flexible Hair‐Like Piezoelectric Acoustic Particle Velocity Sensor with Enhanced Sensitivity for Speaker Recognition

Abstract Flexible resonant acoustic sensors exhibit enhanced sensitivity near their resonant frequencies and have attracted increasing interest as essential components for next‐generation human‐machine speech interactions. However, membrane‐based resonant acoustic sensors are bulky owing to the inherently high bending stiffness of the sensing membrane. Inspired by the tiny hair‐based sensitive acoustic receptors of spiders, this study reports a hair‐like piezoelectric resonant acoustic particle velocity sensor (HP‐APVS) that enables highly sensitive sound sensing with a significantly reduced size. The HP‐APVS device is essentially a polyimide cantilever array fabricated using Nb_0.02‐Pb(Zr_0.6Ti_0.4)O₃ (PZT) on polyimide and self‐bending processes. The experimental results demonstrate that the HP‐APVS shows a linear response to acoustic particle velocity instead of acoustic pressure, with enhanced sensitivity in the resonance mode. Additionally, the proposed HP‐APVS exhibits an outstanding speaker recognition rate of 95.3% with an error rate reduction of 75% compared with that of a reference commercial microphone, indicating many potential applications in the realms of biometric authentication, voice user interfaces, and other intelligent acoustic electronics.