Patterning Gradient Properties from Sub-Micrometers to Millimeters by Magnetolithography

Abstract

A new method is presented for patterning surfaces with gradient properties. The method is based on magnetolithography in which the surface patterning is performed by applying a gradient of a magnetic field on the substrate, using paramagnetic metal masks in the presence of a constant magnetic field. Superparamagnetic nanoparticles (NPs) are deposited on the substrate, and they assemble according to the field and its gradients induced by the mask. Once they pattern the substrate, they protect their sites on the substrate from interacting with any other species. The areas not protected by the NPs can be covered by molecules that chemically bind to the substrate. After these molecules are bound, the NPs are removed, and other molecules may be adsorbed on the newly exposed area. The new technique is based on a parallel process that can be carried out on a full wafer. It provides high resolution, it creates gradient continuously from sub-micrometers to millimeters, and it can be performed on surfaces that are not flat and that are even on the inside of a tube. The gradient that is formed is not limited to a specific property or type of substrate.

Large-Area, Ensemble Molecular Electronics: Motivation and Challenges

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Gradient wettability induced by deterministically patterned nanostructures

“…In addition, electrochemistry has also been applied to fabricate morphology gradients, where in-plane potential gradients are utilized to generate progressively varied nanopores 26 . Many other approaches based on magnetic 27 , thermal [28][29][30] , and humidity 31 gradients have also been used to fabricate gradient topography surfaces.…”

Silica‐Coated Magnetite Nanoparticles Carrying a High‐Density Polymer Brush Shell of Hydrophilic Polymer

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