Solvent processing of PMMA and COC chips for bonding devices with optical quality surfaces

Many prototype microfluidic devices are manufactured by some form of micromachining or injection molding which often leaves poor quality surface. This work presents a simple method that both significantly reduces surface roughness of microfluidic chips and at the same time is used to bond devices. The method has been tested on devices made from poly(methyl methacrylate) (PMMA) and cyclic olefin copolymer (COC). The technique uses a solvent vapour exposure process which creates an irreversible bond between two substrates. It also re-flows the material, producing surfaces with optical quality.