Development of a high–resolution rapid prototyping system for small size objects

Abstract

A high-resolution stereolithography (SL) system for fabricating small objects with complex microstructures has been developed. This novel SL system consists of a single mode He-Cd laser, an improved optical scanning system, a novel recoating system and a control system. A laser light spot with the diameter of 12.89 μm on the focal plane is obtained with the improved optical scanning system, and resin layers with the thickness of 20 μm can be built with the novel recoating system. Experimental studies were carried out to investigate the influences of the build parameters on the cured line width and depth with this novel SL system. The experimental results showed that the cured depth and width increase with the increasing ratio of laser power to scanning speed. And it is found that the cured line built using the high-resolution SL system is smaller in width and deeper in depth compared with the cured line fabricated in conventional SL system under the same scanning conditions. Based on the cured line width and depth obtained in the experiment, empirical equations predicting the cured line width and depth according to the ratio of laser power to scanning speed are established using a least-square fitting. The cured line width and depth predicted by the empirical equations provide a foundation to set up accurate line width compensation and appropriate layer thickness in the high-resolution SL system. Some small objects with microstructures have been fabricated with the new SL system.