PMUT

Piezoelectric Micromachined Ultrasonic Transducers (PMUT) are MEMS-based piezoelectric ultrasonic transducers. Unlike bulk piezoelectric transducers which use the thickness-mode motion of a plate of piezoelectric ceramic such as PZT or single-crystal PMN-PT, PMUT are based on the flexural motion of a thin membrane coupled with a thin piezoelectric film, such as PVDF.<ref>Trolier-McKinstry, Susan; P. Muralt (January 2004). "Thin Film Piezoelectric for MEMS". Journal of Electroceramics. 12 (1–2): 7. doi:10.1023/B:JECR.0000033998.72845.51. S2CID 108579867.</ref><ref>Hajati, Arman; et al. (2012). "Three-dimensional micro electromechanical system piezoelectric ultrasound transducer". Applied Physics Letters. 101 (25): 253101. Bibcode:2012ApPhL.101y3101H. doi:10.1063/1.4772469.</ref><ref>Muralt, Paul (December 2005). "Piezoelectric micromachined ultrasonic transducers based on PZT thin films". IEEE Trans Ultrasonics, Ferroelectrics. 52 (12): 2276–2288. doi:10.1109/TUFFC.2005.1563270. PMID 16463493. S2CID 24177361.</ref><ref>Qiu, Yongqiang; et al. (2015). "Piezoelectric Micromachined Ultrasound Transducer (PMUT) Arrays for Integrated Sensing, Actuation and Imaging". Sensors. 15 (4): 8020–41. Bibcode:2015Senso..15.8020Q. doi:10.3390/s150408020. PMC 4431219. PMID 25855038.</ref><ref>Brown, Lewis (November 2000). "Design Considerations for Piezoelectric Polymer Ultrasound Transducer". IEEE Trans Ultrasonics, Ferroelectrics. 47 (6): 1377–1396. doi:10.1109/58.883527. PMID 18238684. S2CID 43756472.</ref> In comparison with bulk piezoelectric ultrasound transducers, PMUT can offer advantages such as increased bandwidth, flexible geometries, natural acoustic impedance match with water, reduced voltage requirements, mixing of different resonant frequencies and potential for integration with supporting electronic circuits especially for miniaturized high frequency applications.