Robuta

https://bsac.berkeley.edu/publications/bpn851-piezoelectric-micromachined-ultrasonic-transducers-corrugated-diaphragms-using BPN851: Piezoelectric Micromachined Ultrasonic Transducers with Corrugated Diaphragms Using Surface... ultrasonic transducers piezoelectric corrugated diaphragms using