Drone-Mounted Low-Frequency pMUTs for > 6-Meter Rangefinder in Air

This paper reports a low-frequency piezoelectric micromachined ultrasonic transducer (pMUT)
with a small attenuation coefficient to realize the long-distance rangefinding applications in air.
Pulse-detection measurements of one pair of pMUT devices show a >6-meter traveling distance in
air under a 37.32 kHz driving frequency. As an example, two pMUT chips are mounted on two
drones as the transceiver and receiver, respectively. Measurements of the separation distance are
conducted based on the Time-of-Flight (ToF) principle with up to 32 fps (frames per second) for
real-time detections. This demo of drone-mounted pMUT system illustrates the advantages of
pMUT in terms of compactness and low power consumption for applications in drones including
obstacle avoidance, inter collision prevention, aerial coordination, and acoustic-based vision.