Topographical patterning of chemically sensitive biological materials using a polymer-based dry lift off

Precise placement of biochemicals on device structures and controlling of the cell culture environment are important for tissue engineering, sensors and fundamental studies of cell behavior. In this article, we describe a dry lift-off method that allows patterning of chemically sensitive biological materials on a variety of surfaces. Using a combination of projection lithography and reactive ion etching, a Parylene coated surface is patterned and subsequently coated with a biochemical layer. The Parylene is peeled from the substrate and the desired chemical pattern or cell pattern is formed. We have patterned antibodies, poly-L-lysine and aminopropyltriethoxysilane (APTS) self assembled monolayers. These surfaces were respectively used to pattern Escherichia coli serotype O157:H7 bacteria cells, rat basophilic leukemia (RBL) cells and 20 nm diameter aldehyde-sulfate coated fluorescent polystyrene beads. Typical patterns consisted of arrays of 5mm long parallel lines of bacteria confined to stripes with widths varying from 2 μm to 20 μm. Such pattern can be made over large areas, and we have done this on areas up to 3 cm².