High-precision 3D printing by deploying expandable microspheres

Stereolithography-based three-dimensional (3D) printing technology is widely employed in various industries, including manufacturing, healthcare, energy, biomedical, art, and other fields. However, precision issues, such as dimensional shrinkage and structural warping, significantly hinder its wide application. In this study, we present a straightforward and efficient yet general strategy to enhance structural fidelity by incorporating thermally expandable microspheres into photosensitive resins. We found that this reduction substantially mitigates the volume shrinkage below 3.98% compared to over 10% for commercial photosensitive resins. Precision improves significantly, with dimensional deviation at just 0.035% compared to over 0.1% with commercial options. Furthermore, due to the low filling ratio, the improvement in 3D printing precision did not affect the mechanical properties; thus, it does not affect applications where those photosensitive resins are originally targeted. Our method represents an effective strategy to improve the 3D printing resolution of photosensitive resins, thus opening directions for high-precision 3D printing technology.