Acoustic Microscopy for Biomedical Applications
12.1 Sound Waves and Basics of Acoustic Microscopy
Similar to other microscopic procedures, acoustic microscopy provides images of specimens. However, in contrast to most light microscopic techniques, these images cannot be interpreted in a straightforward manner; instead, a detailed analysis is required to extract the information hidden within the images. The difference between light and acoustic microscopy corresponds to the difference between visual comprehension of our world and the information gained by feeling with fingers. Thus, the information gained is complementary.
Investigating mechanics on a microscopic scale seems strange in a biomedical world considering genomics, proteomics, and the interactions of signal transduction chains as the main clues for understanding how a cell or an organism functions. Indeed, all these molecular processes determine the function of a cell, which finally is a physical unit with a given shape and thus exerting mechanical forces, electrical currents, just physical properties. Comprehension of cells or organs on this level of organization is a holistic one, because mechanical forces as well as voltages and currents require a complete system of action and reaction where forces can be balanced or can produce movements in cases where they would not be in equilibrium. ...