Non-contact thermoacoustic detection of embedded targets using airborne-capacitive micromachined ultrasonic transducers
Abstract
A radio frequency (RF)/ultrasound hybrid imaging system using airborne capacitive micromachined ultrasonic transducers (CMUTs) is proposed for the remote detection of embedded objects in highly dispersive media (e.g., water, soil, and tissue). RF excitation provides permittivity contrast, and ultra-sensitive airborne-ultrasound detection measures thermoacoustic-generated acoustic waves that initiate at the boundaries of the embedded target, go through the medium-air interface, and finally reach the transducer. Vented wideband CMUTs interface to 0.18 μm CMOS low-noise amplifiers to provide displacement detection sensitivity of 1.3 pm at the transducer surface. The carefully designed vented CMUT structure provides a fractional bandwidth of 3.5% utilizing the squeeze-film damping of the air in the cavity.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Feb 23, 2015
- Source ID
- 10.1063/1.4909508
Entities
People
- Amin Arbabian
- Amin Nikoozadeh
- Anshuman Bhuyan
- Butrus T. Khuri-yakub
- Hao Nan
- Kevin C Boyle
- Miaad S. Aliroteh
- Nikhil Apte
Organizations
- Defense Advanced Research Projects Agency
- Stanford University