Optimization of coatings for vascular stent with ultrasonic spray technology

Abstract

Ultrasonic spray technology is used to prepare the coating of stent. Based on the mechanism of coating surface and the parametric model of ultrasonic spray process, an orthogonal experiment using THF and 30% PEO-PSF is carried out to optimize the processing parameters. It shows that the flow rate, gas pressure and feeding speed are the main parameters influencing the quality of coating surface. Besides, experiments have verified the rationality of optimized parameters, and the optimized process eliminates the common surface defects such as webbing, bridge, etc. AFM image indicates that within a 2μm×2μm scope, the coating roughness is reduced from 6.35nm to 1.72nm which improves the surface quality remarkably. The weighted results of coating mass tells the average mass deviation is about 7.5μg which shows the ultrasonic spray process has good repeatability. © 2012 Springer-Verlag.