Wrinkle‐Assisted Capillary Bridging for the Directed Assembly of Single‐Level DNA Nanowire Arrays

Abstract Assembly of molecular‐scale nanowire arrays with defined spacing in an inexpensive and time‐efficient manner enables the development of versatile functional nanodevices that are unattainable with conventional approaches involving top‐down patterning techniques. This paper introduces a bottom‐up method for rapidly assembling DNA molecules into periodically aligned 2‐nm‐thin nanowires. The method uses wettability‐contrast channels composed of superhydrophilic wrinkles with a periodic high‐aspect‐ratio structure as the top and a hydrophobic flat surface as the bottom. After injecting the channels with DNA solution, one end of the wrinkled top is detached to facilitate unidirectional receding of an array of submicrometer‐scale capillary bridges developed in between. The molecules confined in each capillary bridge are then made to evaporatively assemble into a linear structure on the flat surface, thus yielding an array of molecular‐scale nanowires. The inter‐nanowire separation can be controlled by tuning the wrinkle dimensions. The wrinkle‐assisted capillary‐bridging method, termed WaCaB, exploits the surface instability of a film–substrate system for wrinkle fabrication and employs a simple detachment process, thus offering a general and flexible pathway for the facile assembly of spatially organized single‐level DNA nanowires, which can create new fabrication opportunities for devices in nanoelectronics, photonics, and biology.