Ultrasonic Imaging of Biofilms Utilizing Echoes from the Biofilm/Air Interface.

Ultrasonic imaging of bioflims in water is difficult due to the very low contrast in acoustic impedance between the biofilm and water. In this paper, biofilms ex- posed to moist air are scanned through the substrate in order to obtain echoes from the bioflim/air interface. A 50 MHz scanning system was used to scan 1 mm X 1 mm areas of biofilms in a 10 μm grid pattern. Two fast Fourier transform (FFT) based methods for enhancement of the film thickness measurement resolution are compared. Using these techniques, the surface topography of biofilms with thickness less than the acoustic wavelength can be imaged. [ABSTRACT FROM AUTHOR]