Rapid, robust and economical fabrication of fluidic microchannels is of fundamental importance for the successful development of disposable lab-on-a-chip devices. In this work, we present a solvent-actuated bonding method for fabricating polymeric thermoplastic microfluidic devices. A PMMA sheet with an imprinted microchannel was clamped to a blank PMMA sheet, then 80 ? 5 ?L of acetone (bonding solvent) was introduced at one end of the fluidic channel and aspirated out at the other end. As the solvent moved down the channel, capillary forces drew a fraction of the solvent into the interstitial space between the two polymeric substrates. After aspiration, the assembly was incubated in the clamp for 5 min for effective bond formation. The quantity of the bonding solvent, its water content and flow rate along with residence time in the channel were found to have significant impact on the bond quality and the channel integrity. Microfluidic electrophoretic separations of a 400-base DNA ladder were performed in devices fabricated using this method in less than 8 min with efficiencies routinely between 2?106 plates/m to 3?106 plates/m. The simplicity and economy of this technique make it amenable for automation and mass production, which could make polymeric substrates more attractive for single use chemical analysis devices.
Citation: Analytical Chemistry
Pub Type: Journals
DNA analysis, Microchip electrophoresis, Microfluidic devices, Poly(methyl methacrylate), Polymer bonding