Microarrays by structured substrate swelling

A technique is presented for manufacturing surface microstructures on polymer substrates. It is based on the uptake of solvent vapors by a prestructured polymer, selective swelling, and the flow of the softened polymer. Prestructuring is done by evaporating material, UV illumination, or ion bombardment through a mask. As an application we describe the fabrication of two-dimensional ordered arrays of microvessels which can be of different shape, size, and material. The bottom of the microvessels can be functionalized by several means and it can be transparent to allow for optical analysis. Applications of the microvessel array are seen in combinatorial chemistry, as microreactors, and as confined spaces for controlling crystal growth.