Fabrication of glass-based microfluidic devices with dry film photoresists as pattern transfer masks for wet etching†
A simple, cheap and rapid method is developed to fabricate glass-based microfluidic devices with dry film photoresists (DFR) as pattern transfer masks for wet etching. In this method, the DFR mask for wet etching can be easily achieved by a one-step lamination, and no expensive facilities and materials are used; therefore, both the difficulty and the cost of fabrication of glass microchips with etched microchannels are reduced greatly compared with those in conventional methods. With the DFR mask, mass-production of glass microchips can be achieved efficiently and controllably in general laboratories. The fabricated glass microfluidic devices feature very flexible design of microchannels, good chemical compatibility and optical properties, easy modification of channel surface wettability, mass producibility and satisfactory reproducibility. We demonstrate the utilities of fabricated glass microchips in the preparation of monodisperse water-in-oil (W/O) and oil-in-water (O/W) emulsions, and the formation of a stable laminar flow interface and concentration gradient in microchannels.