Irregularities and Voids
Microfluidics Channel Defects - Application Note 2158
Sample & Method
A plastic plate on which separation channels 50 microns wide lead from peripheral wells and converge on a central anode well. After etching of the channels, a plastic cover is bonded to the plate. Ultrasound is focused through the plastic to inspect the bond interface.
A critical step is the thermal bonding of the two plates without deformation of the channels and wells. The planar acoustic image shows irregularities and discontinuities of a channel, in addition to random voids between the two plates.