Zero-power self-aware microsystem platform enabled by passive acoustic switch

Abstract

Long-term continuous monitoring is essential for the Internet of Things (IoT), with efficient power use and sustainable energy supply as core challenges. This study presents a MEMS-based self-holding acoustic switch designed for uninterrupted monitoring of specific acoustic signals with zero power consumption. Microelectromechanical systems (MEMS) refer to miniaturized devices that integrate mechanical and electrical components on a single microchip. A mathematical model is developed to analyze the switch's acoustic frequency response. Simulations and experiments demonstrate its acoustic-driven properties. Acoustic switches with different structural parameters are designed, achieving resonant frequencies ranging from 192 Hz to 862 Hz. Electrostatic voltages are applied to enable self-holding functionality, and the acoustic switch exhibits a contact resistance as low as 29.3 Ω. The acoustic switch successfully performs various functions, including acoustic sensing, frequency identification, on–off control, and self-holding, all without drawing power from an external power supply. By integrating this acoustic switch, a zero-power self-aware microsystem platform is realized, allowing zero-power sleep states without closed-loop circuits while remaining responsive to target acoustic signals. This technology effectively supports long-term, large-scale deployment of unattended IoT terminals.