CMOS Compatible Acoustic Particle Velocity Sensors

In this work we propose 2D acoustical particle velocity (APV) sensors produced by post processing silicon chips designed with the STMicroelectronics 0.32 μm BCD6s process. The sensors consist of two conductive wires suspended on dielectric membranes, separated by a 10 μm air gap. Heat exchange between the wires, heated by an electrical current, is modulated by the local velocity of the medium, producing temperature oscillations, which are transformed into voltage oscillations by the wire temperature coefficient of resistance (TCR). Experimental characterization of the sensors, based on the standing wave tube method, is presented.