(1) The traditional ultrasonic sensor transducer material is mainly piezoelectric ceramic or piezoelectric composite material, which has poor bending resistance or high temperature resistance and low conversion efficiency;
(2) Traditional sensors are rigid probes, ultrasonic waves are emitted by a single chip, can only be transmitted point to point, the transmission surface is narrow;
The base of the traditional ultrasonic probe is flat and rigid. When scanning curved, wavy, angular and other irregular surfaces, it cannot maintain good contact, and the detection accuracy and efficiency are low, which seriously limits the application range of ultrasonic sensors.
The phased array sensor is also a rigid probe. Ultrasonic waves are emitted by multiple chips, and the probe must be customized according to the shape of the object being measured. The mechanical processing and probe calibration are complex and costly. Although the ultrasonic transmission surface is expanded, it remains a point contact, leading to insufficient detection depth and incomplete coverage of the transmission surface. Defects parallel to the sound beam cannot be detected, and this issue has not been fundamentally resolved;
(3) The detection (monitoring) of heterogeneous surfaces requires a large number of customized non-standard probes, which is costly and has low accuracy, so it cannot realize the monitoring of complex systems such as structures;