A Study of an Integrated Approach for Design, Ultra-precision Machining and Characterization of Micro-structured Surface with Self-cleaning Properties

摘要

Biomimetics is a burgeoning study and has received more and more research attention during the past few years. The generation of such hydrophobic surface requires strong water repellence which is usually realized by either the fabrication of a rough surface from low surface energy material, or the modification of a rough surface with low surface energy. With the advancement of the ultra-precision machining technology, the modification of a rough surface with low surface energy appears to be a more prospective and flexible method to produce selfcleaning surface. This paper presents a study of an integrated approach for design, fabrication and characterization of patterns of micro-structured surface with self-cleaning properties by using ultra-precision machining technology such as Fast Tool Servo (FTS) machining and ultra-precision raster milling. The study starts with the design of micro-structures, which is based on the observation of some microstructures in nature, as well as theoretical computation for the water contact angle and contact-angle hysteresis. According to the scales and patterns of the micro-structured surface, proper machining method is selected to produce the microstructured surface. The machined surface is then examined by Scanning Electron Microscope (SEM) as well as micro/nano dimensional metrology which accesses the surface quality in terms of roughness and form error, etc. Two types of micro-structured surfaces are designed, and their optimum geometrical parameters are analyzed mathematically and graphically.