Swelling-Driven Ultrafast Soft Lithography.

Abstract

Soft lithography using polymeric molds is a cost-effective and scalable technique but is often limited by long processing times, high temperatures, and production costs. Here, stretchable polydimethylsiloxane (PDMS) molds replicated from compact discs (C-PDMS molds) are introduced for ultrafast, high-resolution patterning on flat, curved surfaces. Unlike rigid polyurethane acrylate (C-PUA) molds, C-PDMS enables rapid patterning within ≈10 s via solvent-induced swelling-the fastest patterning reported. Despite the swelling of C-PDMS molds, an optimized solubility parameter of the processing solvent ensures precise pattern fidelity. Additionally, C-PDMS molds conform to uneven surfaces, overcoming the limitations of rigid C-PUA molds. Their stretchability further enables shape-deformable patterning, allowing controlled feature dimensions and geometries tuning. This capability facilitates the fabrication of polymeric and metallic structures with submicron (≈500 nm) electrode gaps and optically transparent metal patterns. Moreover, overlapped metal structures, such as metal grids and metal island arrays, can be fabricated without needing multiple expensive master molds, substantially reducing fabrication complexity and cost. These findings establish C-PDMS-based ultrafast and conformal soft lithography as a versatile platform for advanced microfabrication.