An air-coupled ultrasonic sensor applying a bimorph structure

Air-coupled ultrasonic sensors are used in various applications such as obstacle detection, distance measurement, and range sensing. Generally speaking, the sensitivity of the air-coupled ultrasonic sensors is low. Therefore, it is expected that the sensitivity will be improved. In this paper, we proposed a new structure for air-coupled ultrasonic sensors. The new sensor has two piezo-electric ceramics that are pasted on both sides of the radiation surface of the sensor. We confirmed that the sensitivity of the proposed sensor is greater than that of conventional sensors through calculations and experiments.