Micromachined ultrasonic transducers for air-coupled nondestructive evaluation

Sean T. Hansen; F. Levent Degertekin; Butrus T. Khuri-Yakub

doi:10.1117/12.339900

28 January 1999 Micromachined ultrasonic transducers for air-coupled nondestructive evaluation

Sean T. Hansen, F. Levent Degertekin, Butrus T. Khuri-Yakub

Proceedings Volume 3586, Nondestructive Evaluation of Aging Aircraft, Airports, and Aerospace Hardware III; (1999) https://doi.org/10.1117/12.339900
Event: Nondestructive Evaluation Techniques for Aging Infrastructures and Manufacturing, 1999, Newport Beach, CA, United States

Abstract

Conventional methods of ultrasonic non-destructive evaluation (NDE) use liquids to couple sound waves into the test samples. This either requires immersion of the parts to be examined or the use of complex and bulky water squirting systems that must be scanned over the structure. Air-coupled ultrasonic systems eliminate these requirements if the losses at air-solid interfaces are tolerable. Micromachined capacitive ultrasonic transducers (cMUTs) have been shown to have more than 100 dB dynamic range when used in the bistatic transmission mode. In this paper, we present results of a pitch-catch transmission system using cMUTs that achieves a 103 dB dynamic range. Each transducer consists of 10,000 silicon nitride membranes of 100 micrometers diameter connected in parallel. This geometry result in transducers with a resonant frequency around 2.3 MHz. These transducers can be used in transmission experiments at normal incident to the sample or to excite and detect guided waves in aluminum and composite plates. In this paper we present ultrasonic defect detection results from both through transmission and guided Lamb wave experiments in aluminum and composite plates, such as those used in aircraft.

Citation Download Citation

Sean T. Hansen, F. Levent Degertekin, and Butrus T. Khuri-Yakub "Micromachined ultrasonic transducers for air-coupled nondestructive evaluation", Proc. SPIE 3586, Nondestructive Evaluation of Aging Aircraft, Airports, and Aerospace Hardware III, (28 January 1999); https://doi.org/10.1117/12.339900

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available