A novel simple preparation method of a hydrogel mold for PDMS micro-fluidic device fabrication

A novel method to prepare a very thick master mold for poly(dimethylsiloxane) (PDMS) casting was investigated by using a hydrogel ultraviolet (UV) curing process through a film mask. A simple process of dispensing of hydrogel, UV curing through a photomask and rinsing enabled the construction of micro-hydrogel structures in a fast manner. These hydrogel structures can be used as a mold for PDMS casting for PDMS fluidic chip fabrication. This method allows the fast construction of very thick micro-structures more than 1 mm. The characterizations about vertical sidewall and adhesion enhancement between the substrate and micro-structures were studied. The application of a PDMS fluidic chip, which was prepared from the hydrogel mold by PDMS casting, to some fluidic flow rate tests was demonstrated. This method is fast and simple to prepare a PDMS casting mold at low cost and can be applied in micro-fabrication of biochemical chips and micro-fluidic devices. (paper)