Segmented projection image translation for large-area, high-resolution vat photopolymerization

High-resolution projection-based vat photopolymerization (VP) 3D printing enables rapid fabrication of highly detailed polymeric structures. However, expanding the build area traditionally compromises resolution, creating a fundamental trade-off between projected pixel size and printable area due to fixed digital micromirror device (DMD) pixel counts. Herein, we introduce segmented projection image translation (SPIN), a simple implementation strategy that expands the effective projection area by applying controlled orbital translation to an off-axis objective lens within the optical infinity space. In this work, we demonstrate a projection-based VP printer implemented with SPIN that expands the effective build area by 4.8-fold, from a native field of 60.4 square millimeters to an expanded domain of 290.5 square millimeters. The SPIN-enabled printer produces isolated line features as thin as 9.8 ± 2.2 micrometers and fabricates intricate three-dimensional truss structures with features as small as 30 micrometers. These results validate a practical route for extending microscale projection-based VP printing to larger build areas while preserving feature fidelity across stitched exposure fields.