This article presents a novel multiband piezoelectric microelectromechanical systems (MEMS) microphone. Equipped with a fully clamped membrane and a closed-loop frequency-tracking system, the proposed microphone achieves acoustic signal detection in both infrasonic and audible frequency bands (with an experimentally verified bandwidth of 0.1 Hz–3.8 kHz). Key innovations include: 1) concurrent infrasound and audio-band operation via a single structural design; 2) piezoelectric actuation-enabled m