Polydimethylsiloxane (PDMS) based microfluidic channels for blood cell analysis were fabricated using etched glass as the master for soft lithography. The design consisted of shallow microchannels with uniformly spaced micropillars that aid in the formation of thin blood films (smear) through capillary filling of the microchannels. The concentration of hydrofluoric acid (HF) and the time duration of etching were varied and conditions optimized for fabrication of microstructures of different depths. Morphological analysis revealed the structure and dimension of the microstructures to be highly consistent. It was also noted that the micropillars formed during soft lithography prevented the roof of the PDMS microchannel from collapsing, a common phenomena observed while using shallow microfluidic channels. The fabricated prototype was used for blood cell analysis and the blood smear formed due to capillary flow was found to eliminate the drawbacks associated with manual smear preparation. Thus, a novel cost effective microfluidic device for cell analysis using glass etching was successfully developed and tested.
J. Raveendran, John Stanley, and Dr. Satheesh Babu T. G., “Fabrication of Shallow Microchannels for Highly Uniform Blood Smear Preparation”, International Conference on Advanes in Materials and Manufacturing Applications (IConAMMA2016), vol. 149. p. 012036, 2016.