Air-coupled Ultrasonic Rangefinder with Meter-long Detection Range Based on a Dual-electrode PMUT Fabricated Using a Multi-user MEMS Process

This work demonstrates the feasibility of an ultrasonic rangefinder with a sensing range of up to 1.5m based on a single piezoelectric micromachined ultrasonic transducer (PMUT) fabricated using a multi-user MEMS process (MUMPs). The dual-electrode design presented herein has been used to isolate the transmit (TX) and received (RX) paths within a single PMUT, thereby avoiding issues of frequency mismatch that is common to dual-PMUT designs. The reported ultrasonic rangefinder has a minimum detection limit of 0.3m.