Tunable Nanochannels Fabricated by Mechanical Wrinkling/Folding of a Stiff Skin on a Soft Polymer

So Nagashima , Hamid Ebrahimi , Kwang-Ryeol Lee , Ashkan Vaziri , and Myoung-Woon Moon
 

Nanochannels can effectively be used for manipulating nanomaterials, such as DNA, proteins, and nanoparticles. Nanolithography-based methods, including electron-beam lithography, focused ion beam patterning, and nanoimprint lithography, have been widely used for the fabrication of nanochannels owing to their excellent patterning resolution, reproducibility, and fl exibility. However, they often involve multistep processes with costly equipment and expertise, and therefore, are not readily accessible. Here, we present a straightforward method for fabricating nanochannels that exploits another type of thin fi lm instability called folding, which emerges during post-instability evolution of surface wrinkles.In our experiments, a fl at PDMS substrate was uniaxially stretched and treated with oxygen plasma for varying durations, resulting in formation of a stiff-oxidized skin of varying thickness on the surface.

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