Advancements in micromachined PC-MUTs for medical devices

The previously reported piezoelectric composite-based micromachined ultrasound transducer (PC-MUT) technology for single crystal lead magnesium niobate-lead titanate (PMN-PT) 1-3 composites has been extended to incorporate multiple resonances, and different resonance modes and patterning. Micromachining provides the capability for patterning that is very difficult using conventional dicing, and designs incorporating multiple resonances in a single device were fabricated. This included both the k_t and k₃₃ modes in a composite of single thickness, and multiple k₃₂ lateral resonances for <;110>; poled PMN-PT using multiple length bars. These designs have distinct advantages for wideband transducers, including dermatology and bone health evaluation.1 Resonance frequencies from 0.3 MHz to 30 MHz were seen with the different techniques.