A Flexible Ultrasonic Sensor Based on Piezoelectric Micromachined Ultrasonic Transducers (pMUTs)

As a large number of robots enter the manufacturing industry, the safety issue of robot obstacle avoidance becomes a key challenge. A flexible ultrasonic sensor is proposed to meet the requirement of the robot safety in this paper. The sensor is composed of two piezoelectric micromachined ultrasonic transducers (pMUTs) at the resonant frequency of 100kHz and a flexible printed circuit board (FPCB), which can be easily attached to the curved robot surface through deformation. The size of pMUT and flexible ultrasonic sensor are 3.5mm × 4mm and 10mm × 25mm, respectively. By comparing the experimental results of the sensing ability of the flexible ultrasonic sensor in the bend state and the flat state, it can be known that the sensing range of the sensor in the bend state is consistent with that of the flat state. The distance and angle sensing range are 25cm – 65cm and −35° - +35°, respectively. The flexible ultrasonic sensor has the potential to be installed on the curved robot surface to sense objects.