Acoustic Velocity Measurement System Using CMUT Technology and a Nickel-on-Glass Process
Sensors and Actuators A: Physical
A micromachined array of 168 nickel-on-glass capacitive ultrasound transducers was used to demonstrate a long range Doppler velocity measurement system. By using an electroplated nickel on glass process, the total capacitance of the chip was reduced to 65 pF, resulting in a high signal to noise ratio and allowing an operable range of 1.5 m. The range is limited by room reverberation level, rather than electronic noise. The sensor array operates at a 180 kHz resonant frequency to achieve a half-angle −3 dB beamwidth of 6° with a 1 cm2 die. The cMUT array was characterized using laser Doppler vibrometry (LDV), beampattern measurements, range testing, and the ability to measure the velocity of a moving plate. The sensor is capable of measuring the velocity of a moving reflector with a resolution of 6 cm/s, at an update rate of 0.016 s, and with a range of 1.5 m (3 m round trip).
Shin, Minchul, Zhengxin Zhao, Paul DeBitetto, Robert D. White.
"Acoustic Velocity Measurement System Using CMUT Technology and a Nickel-on-Glass Process."
Sensors and Actuators A: Physical, 208: 37-49.
doi: 10.1016/j.sna.2013.12.025 source: https://doi.org/10.1016/j.sna.2013.12.025