Calibrated, MHz-Bandwidth, Dynamic Pressure Sensors for Quantitative Measurements in High-Speed Flows – AIAA Jun 2023

This paper describes the development and experimental characterization of a high-bandwidth dynamic pressure sensor designed for use in high-speed boundary layer measurements. The aluminum nitride (AlN) piezoelectric microelectromechanical systems (MEMS) sensor is fabricated using a novel, low-cost approach to creating backside electrical contacts, creating a flush-mount sensing surface without the use of through-silicon vias. Use of miniaturized preamplifier electronics and novel packaging methods enable the final 3.2 mm diameter form factor. Characterization of the device demonstrates improved performance over commercially available high-bandwidth pressure sensors, with a low-frequency cut-on below 40 Hz, a +3 dB upper bandwidth limit of 853 kHz (but useable up to 1 MHz accepting a +4.4 dB upper bandwidth limit and applying the frequency response correction), a flat-band sensitivity of 1.04 uV/Pa, a minimum detectable pressure (MDP) <100 mPa for frequencies >4 kHz, and an estimated maximum linear pressure of 2.1 MPa (300 psi). The reciprocal nature of the dynamic pressure sensor enables a complete magnitude and phase response calibration up to 2 MHz (beyond the 1.77 MHz sensor resonance) via laser vibrometer.

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