Preparation of PEG materials for constructing complex structures by stereolithographic 3D printing

The 3D printing of biocompatible materials is very promising due to their potential for use in biological applications, such as the development of artificial organs. Among various 3D printing methods, stereolithography is a good candidate due to its ability to produce high-resolution structures. Although the 3D printing of hydrogels has been investigated, few studies on printing complex structures have been conducted. In this study, we investigate various challenges during the construction of complex structures such as tilted ratchets and ladders which has T-shapes using UV-curable PEG materials as well as the mechanisms to address these problems. We study the effect of UV absorbing pigments to control the UV penetration depth and the relation with the slice thickness. Also, we design ladder-type structures with different neck widths to verify the mechanical strength of the prepared hydrogel polymers. We raise issues regarding the 3D printing of complex structures using UV-curable materials. Models of failures based on the transparency of the UV-curable materials, high absorption not reaching the upper parts, and mechanical failure are discussed.