★ Use of polymers for CMUTs. ★ Properties when attached to a solid. ★ Lamb wave identification. ★ Detection of simulated acoustic emission. ★ Vibration monitoring application.
Transducers based on a capacitive micromachined ultrasonic transducer (CMUT) design have been fabricated using a rapid prototyping technique. This results in a device that is constructed principally from polymers, in a process which is simple and inexpensive. The resultant devices can be attached to the surfaces of solids. Their peak sensitivity is in the 80–100 kHz range, making them ideal for applications such as acoustic emission and structural health monitoring. Good low frequency sensitivity leads to applications in vibration monitoring.