Metal electrodes in plastic microfluidic systems

We have developed a novel technique for fabrication of plastic microfluidic systems with integrated metal microelectrodes. This technique includes: (i) optical lithography in the ma-P1275 photoresist previously coated on a metal substrate, (ii) electroplating of gold or copper, (iii) photoresist stripping, (iv) embedding of the metal structures in the UV curable resin Acrifix 192 (R), (v) UV curing of the resin, (vi) removal of the metal substrate - by peeling off or etching, and (vii) thermal bonding of the embedded electrodes to a mate with fluidic structures. Relatively high thickness of the metal structures built-in in the curable resin provides for a high mechanical stability of such structures. The fabrication procedure was successfully tested in the fabrication of microfluidic devices for three different applications: (i) an electrochemical microfluidic system called electrolyte diode, (ii) A microfluidic system with an embedded cation exchange membrane, and (iii) AC and DC electroosmotic micropumps with arrays of metal electrodes. (C) 2009 Elsevier B.V. All rights reserved.