Design and fabrication of a piezoelectric micromachined ultrasound array transducer for photoacoustic imaging applications

Piezoelectric micromachined ultrasonic transducers (pMUTs) have been developed for various applications [1], and the design may vary according to the intended use. In particular, membrane type transducers have been widely used for ultrasonic applications in air [2], and are frequently using in transducer arrays for medical ultrasonic imaging systems for robotic surgery as well as for conventional surgical procedures [1]. Ultrasonic transducers for imaging systems generally operate around the resonant frequency to obtain high sensitivity. Here, we report apMUT array with a resonant frequency of 10 MHz for photoacoustic imaging (PAI) applications. The array was fabricated using a bulk micromaching process. The characteristics and performance of the pMUT array were evaluated, and the device was found to be an effective transducer for a PAI system.