Accession Number : ADA308946

Title :   Micromachined Ultrasonic Transducers.

Descriptive Note : Summary rept. 1 Jun 95-31 May 96,

Corporate Author : STANFORD UNIV CA EDWARD L GINZTON LAB OF PHYSICS

Personal Author(s) : Khuri-Yakub, Butrus T.

PDF Url : ADA308946

Report Date : MAY 1996

Pagination or Media Count : 8

Abstract : Micromachined ultrasonic transducers have been fabricated which operate both in water and in air. Broadband ultrasonic transmission in water was verified with the same pair of transducers at frequencies from 1 to 16 MHz. Resonant frequencies in air range from 1 to 12 MHz, with bandwidths from 5% to 20%, depending on the geometry of the device. The dynamic range of the transducers in water is theoretically calculated to be as high as 160 dB. The dynamic range in air can theoretically exceed 100 dB, but nonlinear effects are experimentally found to limit the linear performance to 80 dB of dynamic range at 3.6 MHz. In air, through transmission in Plexiglass at 5 MHz is reported as is the detection of a 25 micron step in silicon at 3.6 MHz. This development effort finds applications in hydrophones, medical ultrasound, nondestructive evaluation, ranging, flow metering, and scanning tip force sensing and lithography.

Descriptors :   *ELECTROACOUSTIC TRANSDUCERS, NONDESTRUCTIVE TESTING, WATER, TRANSMITTANCE, LITHOGRAPHY, RESONANT FREQUENCY, NONLINEAR SYSTEMS, ULTRASONICS, HYDROPHONES, MEDICAL EQUIPMENT, DYNAMIC RANGE, MINIATURE ELECTRICAL EQUIPMENT, BROADBAND TRANSDUCERS.

Subject Categories : Acoustic Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE