MULTIPLEXED ACOUSTIC MICROSCOPY

A new approach to acoustic microscopy using multiplexed or coded
imaging is proposed. This new approach is expected to offer improvements
in signal-to-noise ratio over existing techniques and to make it possible
to produce a small, compact microscope occupying only a few cubic
centimeters (exclusive of electronics) and having no mechanical scanning.
Images should be obtainable rapidly, with the goal being video rates. The
main cost will be in the electronics, so it will be possible to have a
large number of microscopes set up simultaneously and sharing the same
electronics and display. Moreover, there will be no water gap or other
coupling fluid, at least in the reflection version of the microscope, so
shear waves can be used. The lower propagation velocity for shear waves
should translate directly into improved spatial resolution. Specific aims of this grant include a detailed theoretical study of
the proposed multiplexed acoustic microscope, development of techniques for
fabrication of the required thin-film transducer array, and design and
fabrication of a prototype electronics system. The end result will be a
demonstration experiment to acquire actual images and verify the concept
of the multiplexed acoustic microscope.