Surface patterning and its application in wetting/dewetting studies

Recent advances in microfabrication have allowed one to pattern the surface of a solid substrate with patches of different wettabilities on the micrometer-sized scale. These textured surfaces provide a well-characterized model system for studying the wetting and dewetting behaviors of liquids on heterogeneous surfaces. They also present a well-defined template to direct the self-organization of liquids on the surfaces of solid substrates, and to form patterned microstructures of various materials without using expensive, clean-room facilities. As demonstrated in a number of studies, the three-dimensional morphologies of the liquid microstructures could be easily controlled by changing the two-dimensional features patterned on the surface of a solid substrate. These demonstrations suggest that microfabrication based on surface patterning and selective wetting or dewetting will offer immediate advantages in applications such as fabrication of microreactor arrays and microfluidic devices, where a liquid (or solution) is the primary material to be patterned. (C) 2001 Elsevier Science Ltd. All rights reserved.