A PDMS microfluidic spotter for fabrication of lipid microarrays

A PDMS microfluidic spotter system has been developed for the patterning of lipid microarrays that require individually addressing each spot area and high spot density. Microarray spot concentration and uniformity are improved by forming array spots through continuous flow whereby a greater amount of lipid in solution will come in contact with and have the opportunity to bind to the substrate surface. Additionally, flow deposition offers more control over spot formation, since the flow rates and deposition times could be uniquely varied for each spot, producing spots with unique concentrations on the surface. The system is significant in that it facilitates the fabrication of high-density arrays with more dilute lipid solutions, which are difficult and sometimes prohibitively expensive to isolate in sufficient concentration for solid pin and ink-jet spotting. Preliminary test deposition using a fluorescent dye has demonstrated a 5-fold increase in deposition density as compared to conventional pin spotting.