About this Abstract |
| Meeting |
2025 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2025)
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| Symposium
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2025 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2025)
|
| Presentation Title |
Eliminating Structural Defects in Large Area Mechanical Metamaterials via Hot Lithography in Large-Area Projection Micro-Stereolithography |
| Author(s) |
David Hahn, Xiaoyu (Rayne) Zheng |
| On-Site Speaker (Planned) |
David Hahn |
| Abstract Scope |
Additive manufacturing enables the creation of architected metamaterials with exceptional structural and functional properties. Large-area projection micro-stereolithography (LAPµSL) can produce large-volume metamaterials with millions of micro-scale unit cells. However, as part size increases, so does the probability of finding embedded defects, such as internal cracks and strut non-uniformities, which often remain undetected due to flawless external appearances. We investigate the mechanisms behind such defects during free-surface metamaterial printing. Our experiments and theoretical models reveal a growing influence of surface tension at the interface between the cured pattern and uncured resin. This effect dominates defect formation in large-area prints. We introduce an in-situ Joule-heating method that minimizes the surface bulging phenomenon, enabling the production of large, defect-free, low-density mechanical metamaterials. Validation via in-situ non-contact resin surface profiling and X-ray computed tomography (XCT) shows mechanical properties approaching theoretical predictions. This work supports scalable fabrication of high-fidelity metamaterials for advanced engineering applications. |
| Proceedings Inclusion? |
Planned: Post-meeting proceedings |