Vibration maps of capacitive micromachined ultrasonic transducers by laser interferometry

Author

Caronti, Alessandro ; Majjad, Hicham ; Ballandras, Sylvain ; Caliano, Giosuit ; Carotenuto, Riccardo ; Iula, Antonio ; Foglietti, Vittorio ; Pappalardo, Massimo

Author_Institution

Dipt. di Ingegneria Elettronica, Roma Univ., Italy

Volume

49

Issue

3

fYear

2002

fDate

3/1/2002 12:00:00 AM

Firstpage

289

Lastpage

292

Abstract

A 1.8-mm /spl times/ 1.8-mm capacitive micromachined ultrasonic transducer (CMUT) element is experimentally characterized by means of optical measurements. Optical displacement measurements provide information on the resonant behavior of the single membranes and also allow us to investigate the dispersion in the frequency spectrum of adjacent membranes. In addition, higher order mode shapes are observed, showing that either symmetrical or asymmetrical modes are excited in CMUT membranes. Laser interferometry vibration maps, combined with quantitative displacement measurements, provide information about the quality and repeatability of the fabrication process, which is a basic requirement for 2D array fabrication for ultrasound imaging.

Keywords

capacitive sensors; displacement measurement; light interferometry; measurement by laser beam; ultrasonic imaging; ultrasonic transducer arrays; vibration measurement; 1.8 mm; 2D array; CMUT; asymmetrical modes; capacitive micromachined ultrasonic transducers; displacement measurements; fabrication process; frequency spectrum; laser interferometry; mode shapes; optical measurements; resonant behavior; single membranes; symmetrical modes; ultrasound imaging; vibration maps; Biomembranes; Dispersion; Displacement measurement; Frequency; Optical device fabrication; Optical interferometry; Resonance; Ultrasonic imaging; Ultrasonic transducers; Ultrasonic variables measurement; Coated Materials, Biocompatible; Electric Capacitance; Equipment Design; Equipment Failure Analysis; Imaging, Three-Dimensional; Interferometry; Lasers; Materials Testing; Membranes, Artificial; Motion; Oxides; Radio Waves; Reproducibility of Results; Resins, Synthetic; Sensitivity and Specificity; Silicon Compounds; Transducers; Ultrasonics; Vibration;

fLanguage

English

Journal_Title

Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on

Publisher

ieee

ISSN

0885-3010

Type

jour

DOI

10.1109/58.990937

Filename

990937