Multilayer patterning technique for micro- and nanofluidic chip fabrication

Polymer micro- and nanofluidic chips become increasingly significant for medical and biological applications. However, it is difficult to fabricate micro- and nanochannels integrately into a polymer substrate due to the reflow and insufficient flow of the polymer. In the present paper, micro- and nanochannels were hot embossed into a multilayer substrate by micromold and nanomold, respectively. To replicate high replication precision nanochannels without damaging the fabricated microchannels, the embossing parameters were optimized by Taguchi and analytic hierarchy process methods. The fabricated micro- and nanochannels were fully sealed at bonding parameters optimized according to the bonding rate of the chip. The fluorescence image indicates that there is no blocking or leakage over the entire micro- and nanochannels. With presented fabrication method, low-cost polymer micro- and nanostructures can be fabricated, which allows for commercial manufacturing of micro- and nanofluidic chips.