Chemical Processing of SU-8 Photoresist to Record the Surface-Driven Microfluidic Flow of Dyed Working Liquid in the Regime of Fluid Mechanics

Subhadeep Mukhopadhyay

Abstract

Chemical processing of negative photoresist SU-8 is performed to fabricate a set of three individualSU-8 based glass microfluidic devices inside the cleanroom laboratory. The major steps of SU-8processing are spin coating using a spin coater, soft baking, ultra-violet (UV) exposure, post exposurebaking, development by SU-8 developer, and hard baking. The indirect bonding for leakage-freesealing is used during hard baking to fabricate the microfluidic devices. Author has prepared thedyed water to be used as working liquid. Author has used the CMOS camera to record each capillaryflow of dyed water. Each fabricated device contains the arrays of square micropillars which arefabricated on the glass bottom wall of device. The filling time of capillary meniscus is lowercorresponding to smaller side length of integrated square micropillars due to lower microfluidicfriction. Leakage-free surface-driven capillary flow is recorded corresponding to each fabricateddevice. Nonlinear meniscus profile is recorded in each microfluidic device. The surface-drivenmicrofluidic flow is generated by thermodynamic reasons according to the published literatures. Thisexperimental work may be useful for commercial bioengineering applications in future.

Abstract

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