Accession Number:

ADA326230

Title:

Micromachined Ultrasonic Transducers.

Descriptive Note:

Annual rept. 1 Jun 96-31 May 97,

Corporate Author:

STANFORD UNIV CA EDWARD L GINZTON LAB OF PHYSICS

Personal Author(s):

• Khuri-Yakub, B. T.

Report Date:

1997-06-01

Pagination or Media Count:

7.0

Abstract:

Microfabricated ultrasonic transducers have been generated which operate in both liquids and gases. Air coupled through transmission of aluminum was observed for the first time using a pair of 2.3 MHz transducers. The dynamic range of the transducers was 110 dB, and the received signal had an SNR of 30 dB. Air coupled through transmission of steel and glass has also been observed. A theoretical model for the transducers has been refined and agrees well with experimental results. A robust microfabrication process has been developed and was used to generate air transducers which resonate from 2 to 12 MHz, as well as immersion transducers that operate in water from 1 to 20 MHz with a 60 dB dynamic range. Optimized immersion and air transducers have been designed and a dynamic range above 110 dB is anticipated. This development effort finds applications in hydrophones, medical ultrasound, nondestructive evaluation, ranging, flow metering, and scanning tip force sensing and lithography.

Descriptors:

• *ULTRASONICS
• *TRANSDUCERS
• MATHEMATICAL MODELS
• NONDESTRUCTIVE TESTING
• AIRBORNE
• FABRICATION
• TRANSMITTANCE
• LITHOGRAPHY
• ACOUSTICS
• ACTUATORS
• HYDROPHONES
• IMMERSION
• MICROMINIATURIZATION

Subject Categories:

• Electrical and Electronic Equipment
• Manufacturing and Industrial Engineering and Control of Production Systems
• Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE