Effect of Acoustic Properties of Lens Materials on Performance of Capacitive Micromachined Ultrasonic Transducers

摘要: The acoustic lens in capacitive micromachined ultrasonic transducers (cMUTs) is pivotal not only for elevation focusing but also insulation from high DC bias voltages. selection of the material crucial realizing full potential a cMUT; particular, impedance, frequency-dependent attenuation, and shear velocity materials should be closely considered during process. By using finite element method, we determined effects these properties on cMUT performance terms signal strength, center frequency, spectral bandwidth. From simulation results, it was found that impedance does considerably influence if value ranges 1.3 to 1.6 MRayl, which similar human tissue. However, both attenuation cause downshift reduction bandwidth, decrease are main factors leading deterioration spatial resolution signal-to-noise ratio an ultrasound image.