Title :
Experiment and simulation validated analytical equivalent circuit model for piezoelectric micromachined ultrasonic transducers
Author :
Smyth, Katherine ; Sang-Gook Kim
Author_Institution :
Dept. of Mech. Eng., Massachusetts Inst. of Technol., Cambridge, MA, USA
Abstract :
An analytical Mason equivalent circuit is derived for a circular, clamped plate piezoelectric micromachined ultrasonic transducer (pMUT) design in 31 mode, considering an arbitrary electrode configuration at any axisymmetric vibration mode. The explicit definition of lumped parameters based entirely on geometry, material properties, and defined constants enables straightforward and wide-ranging model implementation for future pMUT design and optimization. Beyond pMUTs, the acoustic impedance model is developed for universal application to any clamped, circular plate system, and operating regimes including relevant simplifications are identified via the wave number-radius product ka. For the single-electrode fundamental vibration mode case, sol-gel Pb(Zr0.52)Ti0.48O3 (PZT) pMUT cells are microfabricated with varying electrode size to confirm the derived circuit model with electrical impedance measurements. For the first time, experimental and finite element simulation results are successfully applied to validate extensive electrical, mechanical, and acoustic analytical modeling of a pMUT cell for wide-ranging applications including medical ultrasound, nondestructive testing, and range finding.
Keywords :
acoustic impedance; equivalent circuits; finite element analysis; lead compounds; micromachining; piezoelectric materials; piezoelectric transducers; sol-gel processing; ultrasonic transducers; vibrational modes; PZT; acoustic analytical modeling; acoustic impedance model; analytical Mason equivalent circuit; arbitrary electrode configuration; axisymmetric vibration mode; circular clamped plate piezoelectric micromachined ultrasonic transducer design; clamped circular plate system; electrical analytical modeling; electrical impedance measurements; electrode size; finite element simulation; lumped parameters; mechanical analytical modeling; microfabrication; simulation validated analytical equivalent circuit model; single-electrode fundamental vibration mode; sol-gel pMUT cells; wave number-radius product; Acoustics; Analytical models; Couplings; Electrodes; Equivalent circuits; Integrated circuit modeling; Vibrations;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
DOI :
10.1109/TUFFC.2014.006725