Micromachined Ultrasonic Transducers.
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.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1996
- Accession Number
- ADA308946
Entities
People
- Butrus T. Khuri-yakub
Organizations
- Stanford University