Residual-layer-free direct printing by selective filling of a mould

Abstract

We have developed a residual-layer-free patterning method by selectively filling the concavity of a mould with liquid solution. The method has potential for large-area roll-to-roll fabrication of micro-devices on the flexible substrates. By choosing an appropriate solution or liquid, such as polymethylmethacrylate (PMMA) solution or epoxy precursor, with suitable dynamic contact angle on the SAM-treated mould, the liquid can be coated on the concavity of the mould only. By using this method, residual-layer-free epoxy pattern could be achieved without the need of an extra step. Without forming a residual layer, the technology could simplify the fabrication of three-dimensional structures with low distortion and smooth edges. Conductive PPy/PMMA patterns can also be fabricated by selective deposition of PMMA/FeCl3 and then exposing to pyrrole/chlorobenzene vapours to induce chemical oxidative polymerization of PPy. The electrical resistivity of PPy/PMMA obtained was 0.17 Ω cm.