Robust conductive micropatterns on PTFE achieved via selective UV- induced graft copolymerization for flexible electronic applications.

Fabrication of stable and functional patterns on the surface of polytetrafluoroethylene (PTFE) remains a great technical challenge owing to its inertness and high hydrophobicity. Here, we report for the first time the fabrication of functional micropatterns on the PTFE surface by selectively irradiating plasma-treated PTFE coated with the monomer solution. A series of uniform, highly dense polydopamine methacrylamide (denoted as PDMA) line patterns with the line/pitch width 20μm/20μm and 50μm/50μm were fabricated on the surface of PTFE (denoted as PDMA-p/PTFE) using dopamine methacrylamide (DMA) as the monomer. The surface graft copolymerization occurs attributed to the universal adsorption of DMA and the low grafting energy barrier, comparing with the polymerization energy barrier, which is also demonstrated by the density functional theory (DFT) calculations. Further, robust, well-defined metal Ag or Cu patterns with the strong adhesion strength are fabricated on the surface the PTFE film by electroless deposition, and demonstrated for applications in flexible electronics. The approach is demonstrated to be versatile for fabrication of PDMA micropatterns onto a wide range of polymeric substrates including polypropylene (PP), and acrylonitrile butadiene styrene (ABS).