Radiation impedance study of a capacitive micromachined ultrasonic transducer by finite element analysis.
In this study, radiation impedance of a capacitive micromachined ultrasonic transducer composed of square-shaped membranes arranged in m × m configuration (m = 1 - 5) is investigated using finite element analysis (FEA) of a commercially available software package(ANSYS). Radiation impedance is calculated for immersed membranes operating in conventional and collapse modes. Individual membrane response within the multi-membrane configuration is analyzed, and excited modes and their effects on radiation impedance and the pressure spectra are reported. This FEA provides an accurate behavior of the acoustic coupling of a thin membrane in a multi-membrane configuration, and extends above the anti-resonance frequency. The first resonance frequency of the membrane is excited for m × m (m ≥ 3) configuration in conventional mode and for m × m (m ≥ 2) configuration in collapse mode. Therefore, this frequency is determined to be responsible for the adverse effects observed in radiation impedance and pressure spectrum. A membrane configuration, which is missing the central membrane from the full m × m configuration is proposed, and is investigated with the FEA. This study is beneficial for the design of precise transducers suited for biomedical applications.
Department of Electrical and Electronics Engineering, Middle East Technical University, Ankara 06800, Turkey.
Baris
B
Bayram
D018130:Diamond; D004867:Equipment Design; D020342:Finite Element Analysis; D008567:Membranes, Artificial; D055616:Microtechnology; D011312:Pressure; D014160:Transducers, Pressure; D014465:Ultrasonics / Q000295:instrumentation*; D014732:Vibration
D008567:Membranes, Artificial; D018130:Diamond