A novel fabrication method for hybrid, microfluidic devices

We present a novel fabrication method for hybrid, disposable microfluidic systems. We show its great potential by manufacturing a 24 channel picoliter dispenser, which can be used as disposable for the fabrication of microarrays. Compared to commercially available TopSpot® printheads [Steinert et al., 2004 and Gutmann et al., 2004] silicon area was reduced down to 7% (8×6.4 mm²) and costs were reduced at least by a factor 50. The hybrid disposable assembly consists of a PDMS multilayer containing reservoirs and microchannels (36×20×2 mm³) and a silicon nozzle chip. This way for the first time we were able to realize perfectly sealed high density fluidic interconnects between silicon and PDMS at a pitch of 375 μm. A key for success was the extension of the already known soft lithography and sandwich molding processes for PDMS multilayer fabrication.