LETTER pubs.acs.org/NanoLett Structural Transformation by Electrodeposition on Patterned Substrates (STEPS): A New Versatile Nanofabrication Method

Biomimetic architectures composed of arrays of high-aspect-ratio (HAR) micro/nanostructures have emerged as a new platform for applications in optics, surface science, and medicine. This class of structures (defined as structures with a ratio of height to width of>5) has been extensively studied as catalyst supports, scaffolds for tissue engineering, substrates for preven-tion of ice nucleation, biomimetic hybrid actuators, plasmonic structures, and microelectromechanical systems (MEMS) and for the control of adhesion, wetting, self-assembly, and heat transfer.19 Typically, fabrication of arrays of HAR structures with long-range order requires a silicon master produced by expensive and laborious top-down lithography (e.g., optical or electron-beam lithography) and chemical or deep reactive ion etching (Bosch process).10 Preparation of molds made of poly-(dimethylsiloxane) (PDMS) or other elastomers with the nega-tive structure of such silicon masters, and subsequent replicatio