An acrylate resin/perfluoropolyether film with enhanced hydrophobicity and lowered adhesion surface for precision printed electronics

Spontaneously patterned circuits are regarded as one of the most promising green manufacturing methods that are non-lithographic and mold-free, attracting increasing attention. Liquid-mimicking surfaces allow polar or non-polar liquids to slide easily on slightly inclined modified surfaces without residue, achieving liquid repulsion and self-cleaning functions. Combining the advantages of this sliding property with specific patterned physicochemical characteristics is expected to further enhance printing resolution. In this manuscript, we developed a heterogeneous composite film consisting of a UV-sensitive (2-nitro-1,4-phenylene)bis(methylene) diacrylate resin film (referred to as NBE) overlaid with a layer of hydrophobic perfluoropolyether (referred to as 507A). The tunable surface property of the NBE resin film under UV light (λ =254 nm) irradiation enables the hydrophobic surface (with a water contact angle, WCA of 112°) of the composite film to a hydrophilic surface (with a WCA of 4°), allowing the formation of patterned wettability surface after light exposure. More importantly, the highly hydrophobic perfluoropolyether surface shows a low adhesive surface, which enables a cleaner surface in the hydrophobic area during printing. Angle-resolved X-ray photoelectron spectroscopy and atomic force microscopy tests revealed the differences in surface morphology and elemental distribution of the composite film before and after UV light exposure. In combination with a photomask, fine circuit structures with minimal L/S of 5/5 μm were successfully achieved. The printed circuit was used for carbon nanotube-based thin film transistors, which displyed charge carrier mobilities of 2.43-5.85 cm2·s-1·V-1, demonstrating the practicality of this precision printing technique.