Multi-ink pattern generation by dip-pen nanolithography

Multiplexed patterns of hydrogels and phospholipids with fluorescent dyes are accomplished by dip-pen nanolithography (DPN). For example, four different dye-labeled hydrogel dot arrays are DPN patterned within 50x50 microm(2) area, and two different dye-doped phospholipids dots and letters with less than 1 microm line-width are also DPN patterned. We demonstrate that multi-ink patterns with precise alignment are able to be printed by DPN within a micron-scale. Moreover, this multi-ink DPN patterning methodology can be extended to delicate bio-materials printing in a subcellular scale with accurate positioning control.