A study of mask planning in projection-based stereolithography using digital image correlation

Abstract

The use of mask-image-projection-based stereolithography process (MIP-SL) in additive manufacturing (AM)for 3D printing of bio-scaffold materials is becoming more widespread. In general, mask optimization, frame compensation, and resin material performance improvement were adopted to improve the curing accuracy of resin in MIP-SL process. In this paper, a mask optimization scheme based on image segmentation technology is developed, where the mask is divided into multiple little squares, hexagons, and triangles. The large-area warping deformation in MIP-SL is therefore transformed to a multiple small area distortion. Digital image correlation (DIC) method is applied to measure the effect of using mask image planning in bio-scaffolds MIP-SL process. A platform of bio-scaffolds resin shrinkage measurement based on DIC method was built to measure the resin deformation under distinct mask image planning. The results show that the deformation of the bio-scaffolds resin during the light-cured process will increase sharply at first and then tend to decrease partially. In addition, shrinkage of square segmentation and hexagon segmentation are reduced by 33% and 27%, respectively. However, the shrinkage of triangle segmentation is hardly reduced because the required time is twice as that of the other two methods.