Solvent-assistant microcontact molding

Solvent-Assisted Microcontact Molding (SAMIM) A small amount of solvent (e.g., methanol, ethanol, or acetone) is spread on a patterned PDMS stamp which is placed on a polymer, such as photoresist. The solvent swells the polymer and causes it to expand to fill the surface relief of the stamp. Feature size as small as 60 nm can be reached. 

The soft elastomeric stamp can be used either as a vehicle for biomolecular surface patterning (an application called microcontact printing (p.CP)) or to create three dimensional reliefs, particularly on polymer materials, as in micromolding in capillaries (MIMIC), microtransfer molding (pTM) or solvent-assisted molding. These techniques have been successfully applied in the fabrication of polymer patterns with dimensions down to the sub-100 nm scale and will be described in this chapter. These patterns have found many relevant applications in the life sciences, where scientists often need to spatially control topographical and chemical properties of surfaces at small scales [1, 5, 6]. 

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