Self-assembled monolayers micro-contact printing

Micro-contact printing (pCP) uses high resolution rubber stamps with inks (e.g. alkanethiols) that form self assembled monolayers (SAMs) on the surface (e.g. thin gold film) that is printed [13]. In one pCP approach, these SAMs act as resists for etching material in the unprinted areas, as illustrated in Fig. 10.11. 

Fig. 10.11. Steps for micro-contact printing. The stamp is first inked with a solution of a material that is capable of forming a self assembled monolayer (SAM) on the substrate that will be printed. In the case illustrated here, the ink is a millimolar concentration of hexadecanethiol (HDT) in ethanol. The substrate consists of a thin layer of Au on a flat support. Removing the stamp after a few...

A common application for elastomeric molds is for micro- or nanocontact printing, where a self-assembled monolayer (SAM) is placed on both planar and curved surfaces via contact with the reliefs on the mold (Figure 6.66). SAMs will be an important architecture for the next generation of nanostructured materials. 

C. N. Sayre and D. M. Collard, Depostion of polyaniline on micro-contact printed self-assembled monolayers of w-functionalized alkanethiols, J. Mater. Chem., 7, 909, 1997. 

Stamps and molds are usually prepared from a master with relief structure on its surface by replica molding where the elastomer precursor is cast onto the master and is peeled off after polymerization. As elastomer most notably polydimethyl-siloxane (PDMS) is used. With micro-contact printing, a nonphotolithographic technique, the stamp prints the replica information onto a support, often in the form of self-assembling monolayers changing the surface characteristics to lipophilic on the contact spots (Fig. 18.4). The noncontacted area can be etched off or plated by deposition in an ensuing step. " ... 

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