Effects of Process Parameters on Direct Deposition Hydrogel Molding for the Fabrication Microfluidic Devices

Advantages of microfluidic devices include miniaturization, easy of integration, small reagent consumption etc., and have led to the wide applications in biomedical field. Fabrication of microfluidic devices is commonly done through microfabrication methods; microfabication-free/using rapid prototyping methods have also been developed in recent years to enable applications of microfluidic devices to a broader range. Our recent study has demonstrated the feasibility of fabricating electrospun fiber embedded microfluidic devices by integrating hydrogel molding and electrospinning (ES) through a multi-layer construction process. This paper focuses on examining how process parameters affect microchannel formation in microfluidic devices fabricated using direct-deposition hydrogel molding (dHGM). PDMS (polydimethylsiloxane) was chosen as the base-material of the device, and Agarose hydrogel was used to generate the mold channels. A direct writing system was used to deposit the hydrogel mold. We examined three parameters affecting the dHGM based microchannel formation: hydrogel composition, curing conditions, and deposition method. Effects of these parameters were characterized in terms of ease-of-handling, consistent channel formation, and control of channel diameter.