SAMIM molding

In order to reduce the adhesion between a polymeric mold and a silicon/quartz master, the master surface is typically modified with a fluorosilane e.g., CF3(CF2)6(CH2)2SiCl3(g)). In addition, the final removal of the mold may also be carried out in the presence of a liquid with a low viscosity such as methanol (solvent-assisted micromolding (SAMIM)). 

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 PRINT technique is analogous to micromolding in capillaries (MMIC) or solvent-assisted micromolding (SAMIM), with the use of perfluorinated polymers rather than silicones (Figure 4.72). The use of PFPE instead of PDMS molds offers the following benefits (Figure 4.73) ... 

Figure 4.72. Schematic of soft lithographic procedures for (a) replica molding (REM), (b) microtransfer molding (pTM), (c) micromolding in capillaries (MIMIC), and (d) solvent-assisted micromolding (SAMIM). Reproduced with permission from Angew. Chem. Int. Ed. 1998, 37, 550. Copyright 1998 Wiley-VCH.

Figures 3.2 and 3.3 show SEM images of several 3D structures formed by soft molding or SAMIM. The circular cones shown in Figure 3.2a have a base diameter of approximately 1 pm. Rounded triangular channels with a period of approximately 3 pm are depicted in Figure 3.2b. A three-level structure is shown in Figure 3.2c. These results demonstrate the effectiveness of solvent-assisted molding in fabricating 3D structures. SAMIM can also replicate complex relief structures over large...

SAMIM is an embossing technique in which a solvent softens a polymer in a form in which it can be molded by a stamp (usually PDMS). As the solvent evaporates, the polymer conforms to the... 

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