title: Characterization of MEMS transducer performance using near-field scanning interferometry.
abstract: Sophisticated ultrasonic transducer microarrays based on micro-electro-mechanical-systems (MEMS) technologies are quickly becoming a reality. A current challenge for many researchers is characterizing the dynamic performance of these and other micro-mechanical devices. In this work, the performance characteristics of a MEMS ultrasonic transducer array were successfully measured using a scanning heterodyne interferometer system. The dynamic response of the entire transducer array was measured, and the results were compared with theoretical predictions. Individual elements were found to vibrate with Bessel-like displacement patterns, and they were resonant at approximately 4 MHz. The full array showed variations in peak out-of-plane displacement levels across the device of 16%, and isolated elements that were dramatically overresponsive and under-responsive. The measured variations across the array may have an undesirable impact on the performance of the transducer and its radiated field.
authors.forename: James L
authors.initials: JL
authors.lastname: Blackshire
authors.forename: Shamachary
authors.initials: S
authors.lastname: Sathish
mesh_terms: D004548:Elasticity; D025802:Electric Capacitance; D004566:Electrodes; D019544:Equipment Failure Analysis; D007368:Interferometry / Q000295:instrumentation* / Q000379:methods; D008027:Light; D008567:Membranes, Artificial; D008904:Miniaturization; D009038:Motion; D036103:Nanotechnology; D012680:Sensitivity and Specificity; D014159:Transducers; D014465:Ultrasonics
chemical_list: D008567:Membranes, Artificial