Titanium is widely used in biomedical components. As a promising advanced manufacturing process, electropolishing (EP) has advantages in polishing the machined surfaces of material that is hard and difficult to cut. This paper presents the fabrication of a titanium microchannel using the EP process. The Taguchi method was adopted to determine the optimal process parameters by which to obtain high surface quality using an L9 orthogonal array. The Pareto analysis of variance was utilized to analyze the three machining process parameters: applied voltage, concentration of ethanol in an electrolyte solution, and machining gap. In vitro experiments were conducted to investigate the fouling effect of blood on the microchannel. The result shows that an applied voltage of 20 V, an ethanol concentration of 20 vol.%, and a machining gap of 10 mm are the optimum machining parameters by which to enhance the surface quality of a titanium microchannel. Under the optimized machining parameters, the surface quality improved from 1.46 to 0.22 μm. Moreover, the adhesion of blood on the surface during the fouling experiment was significantly decreased, thus confirming the effectiveness of the proposed method.

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In this paper, we present electropolishing method to fabricate a thin-structural layer of microfilter which is used for filtering blood in hemodialysis system. The electropolishing method removes material based on electrolysis process, in which material removal is done through electrical current which trigger material removal by chemical reactions. The preliminary experiment shows that the SS 316L structural layer was able to be fabricated in less than 7 minutes, under machining parameter of 7 V of DC voltage, 2 cm gap between tool electrode and workpiece, and utilizing 15% of NaCl in pure water. This promising result has indicated that electropolishing could further be used as a method to make thin-structural layer of microfilter for hemodialysis system.