Optomechanical acoustic particle velocity sensor

Inspired by the velocity-sensitive ears of animals, vector acoustic sensing using viscous-driven mechanical structures is emerging as a promising alternative to traditional pressure-based sound detection. However, realizing low-noise transduction in miniaturized velocity sensors remains a significant challenge. Here, we present an optomechanical acoustic particle velocity sensor that integrates a microscale viscous-driven structure with fiber-optic interferometry to enable high-sensitivity, low-noise acoustic measurements. This vector sensing approach overcomes fundamental limitations of scalar pressure-based acoustic sensors, offering intrinsic advantages in directional sound detection, source localization, and noise rejection.