4D Scanning Acoustic Microscopy

Scanning acoustic microscopy (SAM) can map mechanical surface properties and topography of materials with high spatial resolution. Coded-excitation scanning acoustic microscopy (CESAM) enables high SNR while maintaining fast imaging. The high scan speed of our CESAM allows us to study how surface mechanical properties change almost in real time. The 4D scanning capability was demonstrated with a UV-curable adhesive coating. The 4D data was constructed from three spatial dimensions and one time dimension. We set the C-scan scan rate to 30 s and measured a 400 mu m x 400 mu m area with 175 MHz and step size of 5 mu m. With 400 MHz and step size of 1.5 mu m we measured one 150 mu m x 150 mu m plane every 30 s.