Characterization and modeling of CMOS-compatible acoustical particle velocity sensors for applications requiring low supply voltages

Modeling and optimization of directive acoustical particle velocity sensors for ultrasonic applications

“…The sensing structure is similar to that proposed in our previous works [14][15][16] and only a brief description is reported here. The device consists of two polysilicon-silicide resistors immersed in the fluid (air) where the acoustic wave propagates.…”

“…Similar devices, consisting of multiple pairs of heated wires, integrated on the same chip by means of dedicated micromachining technologies, have been proposed for 2D [8][9][10] and 3D [11][12][13] APV measurements. Recently, the possibility of fabricating APV sensors with a CMOS-compatible fabrication technique has been demonstrated [14][15][16]. APV sensors have been proposed for diverse applications, including acoustic impedance and absorption coefficient measurement [17][18][19], sound intensity measurement [20], direction of arrival estimation [21], near-field acoustic holography [22,23] and noise source localization [24].…”

“…The geometric dimensions of each structure have been optimized in order to obtain the maximum sensitivity. The optimization has been performed by means of finite element simulations based on an original enhanced 2D model [15], whose greater computational efficiency, with respect to full 3D models, allowed the execution of detailed parametric sweeps in reasonable times.…”

A CMOS compatible micro-Pirani vacuum sensor based on mutual heat transfer with 5-decade operating range and 0.3 Pa detection limit

“…Two pressure-sensitive structures are placed into a single test-chip that includes a low-noise analog front end (AFE). The chip, whose dimensions are 3.86 x 3.86 mm 2 , includes also several flow sensors [26] and acoustical sensors [27], described elsewhere. Both the pressure sensors and the AFE are accessible through dedicated bonding pads.…”

Thermal Noise-Boosting Effects in Hot-Wire-Based Micro Sensors

“…Such an arrangement allows detection of both the magnitude and direction of airflows [9]. Recently, wire pairs with thermal mass as small as to allow temperature variations with frequencies up to several kHz have been used to detect the local fluid displacement induced by an acoustic wave [10][11][12][13]. In particular, this new class of sensors is capable of directly detecting the acoustic particle velocity (APV), enabling interesting applications that cannot be easily achieved with standard microphones [14].…”