Achieving Selective Wettability Surface through Aerosol Jet Hydrophobic Line Printing.

Selective wettability surface patterning, involving the combination of wetting and nonwetting surface features in an alternating manner, has emerged as a key surface control technique with broad applications in cell microarrays, microfluidics, and drop placement. However, traditional approaches to creating such patterns often suffer material waste and rely on masking substrate surfaces with predesigned templates, resulting in elevated costs. Here, we present an approach to achieve selective wettability surface patterning using aerosol jet printing that offers a solution to these challenges. Our method involves the precise deposition of atomized, hydrophobic silica nanoparticle droplets onto substrate surfaces. By directing these atomized droplets, we created well-defined hydrophobic lines. The individual lines have an average width of 60 μm and a thickness of 1.32 μm, which, when overlaid, form a complete superhydrophobic surface with a water contact angle of 154°. The implications of these findings are substantial for various applications. We accordingly show the applicability of our method for confining drops and demonstrate on-target waterproofing of electronic circuit lines.