Self-assembled Monolayer Films: Microcontact Printing

lithographic techniques that make up "soft lithogra-phy " (Xia and Whitesides 1998), uses an elastomeric stamp to generate two-dimensional patterns by print-* ing the molecules of an "ink " onto the surface of a solid substrate. In its most common configuration, the stamp is fabricated from an elastomeric polymer, poly(dimethylsiloxane) (PDMS), the "ink " is an alkanethiol, and the substrate on which the printing occurs is a thin, evaporated film of gold or silver. Alkylsiloxanes are also printed on Si/Si02 and glass. Microcontact printing is an experimentally simple methodology; the elastomeric stamp is easily fabri-cated by molding a liquid prepolymer against a master that has the desired pattern in relief on its surface. Once the master is available, multiple copies of th