MEMS phased array detection in contact with solids

We report on the development of transducers for ultrasonic flaw detection which can be permanently mounted at critical locations on structures. We will show that MEMS capacitive diaphragm transducers can be bonded to metal or plexiglas test specimens without damage and that ultrasonic energy can be efficiently coupled into the transducer. It will be demonstrated that transducer arrays can be operated as a phased array in order to determine the direction and distance of an ultrasonic source. In addition, the detection of flaws or voids in a test specimen will also be demonstrated.