Characterization of thin biological tissue with scanning acoustic microscopy

The present article reports a technique to measure velocity of a biological specimen, wherein the thickness of the biological specimen and the diameter of the measurement area of the specimen are in the order of a few microns. The kidney was selected for the specimen as an example of the soft material. The kidney was thinly sliced by a microtome and located on a substrate. The thickness of the specimen was substantially 3 μm. For the substrate, fused quartz was used because its elastic properties are known and stable. The spherical acoustic lens was used to determine the position for the measurement. The frequencies of 400 and 600 MHz were used for the measurement and the visualization respectively. The generation of the Rayleigh waves in the above conditions was simulated by numerical calculations based on the wave propagation theory for layered media.