Simple method for reversible bonding of a polydimethylsiloxane microchannel to a variety of substrates

The low-cost prototyping of complex lab-on-chip systems requires the development of simple techniques for the reversible bonding of microfluidic channels onto different substrates. The authors report on the use of dimethyl methylphenylmethoxy siloxane (DMPMS) spin-coated layers for the bonding of polydimethylsiloxane (PDMS) microchannels onto a substrate, using the common oxygen plasma method. The DMPMS layer adheres to various surfaces such as glass, silicon, gold, cyclo-olefin copolymer and tantalum and its thickness can be varied by diluting it with heptane. The authors show that the flexible polymer device constituted of the DMPMS layer and the PDMS microfluidic channel can be easily removed from the substrate, allowing the reuse of the latter. The proposed method was used to bond a PDMS microchannel onto an array of Ta-capped micromagnets and an application of this recyclable microfluidic device is presented.