Surface micromachined capacitive ultrasonic transducers

摘要

The current state of novel technology, surface microfabricatednultrasonic transducers, is reported. Experiments demonstrating both airnand water transmission are presented. Air-coupled longitudinal waventransmission through aluminum is demonstrated, implying a 110 dB dynamicnrange for transducers at 2.3 MHz in air. Water transmission experimentsnfrom 1 to 20 MHz are performed, with a measured 60 dB SNR at 3 MHz. Antheoretical model is proposed that agrees well with observed transducernbehavior. Most significantly, the model is used to demonstrate thatnmicrofabricated ultrasonic transducers constitute an attractivenalternative to piezoelectric transducers in many applications