Pioneering techniques for achieving high-resolution, ultrasmooth surfaces via LCD 3D printing technology

Recently, the photocured polymerization method in 3D printing technology has gained popularity on the market due to its advantages of high resolution, low cost, and easy operation. However, the presence of surface texture defects resulting from the LCD panel's pixel array has limited the smoothness of the printed models, rendering the array unsuitable for optical component fabrication. These texture defects are attributed to the black matrix area created by the pixel array, which becomes an apparent voxel defect in the SEM image and leads to an uneven printing surface. To overcome this challenge, a novel design with hybrid LCD films has been developed to eliminate voxel defects. The upper LCD panel is designed to control the direction of light by the voltage-modulated liquid crystal. The scattered light covers the black matrix, achieving a continuous and uniform printed surface. In this research, it is confirmed that the hybrid LCD system significantly alleviates texture defects caused by the black matrix among pixels. The results successfully revealed an ultrasmooth surface, achieving an 80 % reduction in roughness through this modified LCD system without compromising printing resolution. The ultrasmooth surface also reduced the shrinkage by up to 95 % and improved the mechanical properties of the printed material due to the dense adhesion of each layer.