Three‐hot‐wire acoustic particle velocity sensor with improved detection capability

Abstract

This Letter proposes a novel 3-hot-wire acoustic particle velocity sensor with high sensitivity and low self-noise for the first time. Three parallel wires, covered with platinum film, are suspended on silicon substrate by MEMS process. The middle wire works as a heater and the left and right ones work as both heaters and temperature sensors. Compared with the 1-hot-wire and 2-hot-wire counterparts, this sensor has higher sensitivity and lower self-noise, showing its potential for sound source localisation, acoustic camera and so on. The self-noise of the sensor is about 15 dB/ Hz √ at 1 kHz and the relative direction sensitivity is as high as 42 dB.

An analytical model of three-hot-wire acoustic particle velocity sensors

“…Li et al proposed a threehot-wire structure. In this structure, two sensing wires work as both a temperature sensor and heater, which can improve the signal-to-noise ratio [19].…”

Design and Optimization of Sensitivity Enhancement Package for MEMS-Based Thermal Acoustic Particle Velocity Sensor

“…The MEMS-based thermal acoustic particle velocity sensor (TAPVS) is a kind of sensor that can directly measure the particle velocity of sound signals [ 2 , 3 , 4 , 5 , 6 ]. In air, sound propagates in the form of longitudinal waves.…”

“…Thus, the direction of sound propagation can be obtained by measuring the direction of acoustic particle velocity. TAPVS shows promising properties for applications in sound source localization [ 7 , 8 , 9 , 10 , 11 , 12 , 13 ], such as engine fault detection [ 14 , 15 , 16 , 17 ], gunshot localization [ 18 , 19 ], and pipe leakage acoustic detection [ 7 , 20 ] etc., which is far superior to microphone arrays for its higher orientation accuracy, smaller size, simpler signal processing [ 21 ], wider working temperature range [ 22 ], lower low frequency self-noise [ 4 , 23 ], and so on.…”