Micro-perforated elastomeric poly(dimethylsiloxane) mask fabricated using high-aspect-ratio micro-pillar arrays for spatially defined surface modification: an unconventional method for establishing a microarray platform

摘要

Herein, we introduce the fabrication of a micro-perforated elastomeric poly(dimethylsiloxane) (PDMS) mask and employ it for spatially defined surface modification. To fabricate the micro-perforated PDMS mask, high-aspect-ratio micro-pillar arrays having millimeter scale height were first fabricated via direct photopolymerization using a thiol–ene-based UV-curable adhesive. Square pillars (500 × 500 μm) and 200 μm circular pillars with 5 and 12.5 in the aspect ratios, respectively, were successfully fabricated with high pattern fidelity, reaching 2.5mm in height. Next, using the micro-pillar-array platform as a master mold, PDMS prepolymer was cast and polymerized to form an elastomeric PDMS mask having micro-perforation arrays. Alternating hydrophilic and hydrophobic surfaces were successfully obtained by oxidizing PDMS-covered Si wafer with corona discharge. Spatially defined chemical functionalities obtained by selective oxidation and subsequent silanization were clearly distinguished via colorimetric detection methods employing ninhydrin and toluidine reagents. The micro-perforated elastomeric PDMS mask enables selective modification of a surface without utilizing photoreactive chemicals and a photomask.