Coupled Piezoelectric Bulk-Micromachined Ultrasound Trasndcuer (cPB-MUT): An Ultrasound Transducer with Enhanced Pressure Response in Liquid and Dense Medium

A new type of ultrasound transducer based on piezoelectric micromachined ultrasound transducer (pMUT) technology was developed, which is called coupled piezoelectric bulk-micromachined ultrasound transducer (cPB-MUT). In this transducer technology the vibration of small pMUTs are coupled to the bulk silicon substrate through the vibration of water or any other dense medium; this produces a strong vibration in the entire substrate. CPB-MUT was designed for underwater applications such as underwater sensor networks and underwater communication in the range of 1-2 meters. A cPB-MUT with a resonance frequency of 33 kHz was fabricated. It is capable of producing about 210 Pa/V at 1cm underwater.