Effects of Mold Rising Angle and Polymer Concentration in Solvent-Assisted Molding

Abstract

We investigated the capillary rise of a thin polymer solution in a simple soft lithographic technique termed "solvent-assisted molding (SAMo)" by using various mold rising angles and polymer concentrations in a good solvent. For patterning and mold materials, poly(methyl methacrylate) (PMMA, M(w) = 120,000) in toluene and poly(dimethyl siloxane) (PDMS) were mostly used. It was found that the capillary rise takes place in two steps: (i) a low-viscosity polymer solution rapidly rises into the cavity (<10 s) with the aid of solvent wetting and (ii) continuous solvent absorption into the mold and evaporation into air. In addition, five distinct microstructures were observed by testing 24 different experimental combinations, which can be classified into completely molded (I), humped (II), completely molded but non-fully filled (III), partially filled (IV), and partially filled meniscal (V) microstructures.

Patterning Methods for Polymers in Cell and Tissue Engineering

“…134 In this way, various micro- or nanopatterns of thermoplastic polymers such as PMMA, PS and PLGA have been constructed with high pattern fidelity. 33,84,85 It is noted in this regard that PMMA and PS have relatively high elastic modulus on the order of several GPa, capable of rendering several tens of nanometer patterns with high physical integrity.…”

Micromolding—A Soft Lithography Technique

“…This technique generates features that are connected by a residual layer, unlike MIMIC. The patterns generated by SAMIM are affected by various parameters such as mold rising angle (angle between substrate and mold sidewall), concentration of the material being molded, and the amount of material being molded [50]. The capillary rise of the material on softening with the solvent can be controlled with the time of contact of the mold.…”

Transparency and superhydrophobicity of cone-shaped micropillar array textured polydimethylsiloxane

“…Some studies have reported the use of polymers to fabricate superhydrophobic surfaces. 2,[12][13][14][15][16][17][18][19][20][21][22][23] Before the polymer casting step, fabrication of the mold plays an important role, and many techniques such as mechanical machining, electrochemical machining, electrical discharge machining and laser beam machining are available for mold fabrication. Among them, laser beam machining offers many advantages such as freedom to use various process materials and simplicity of fabrication.…”