Toward Predictive Dimensional Accuracy in DLP-Fabricated Alumina Lattices: Volumetric Error and Shrinkage Control

This work introduces a quantitative framework that couples slurry formulation, curing dynamics, and lattice architecture to predict and control defects in DLP-fabricated alumina ceramics. While prior studies have primarily focused on slurry optimization, this study advances the field by establishing predictive correlations between solid loading, shrinkage, staircase error, and mechanical performance. Increasing alumina content from 60-80 wt % reduced volumetric shrinkage from 29.2% to 9.7% and enhanced density up to 90.1%. The staircase effect in ceramic lattices was quantified using cusp height (∼35 μm) and volumetric error (1.77 × 10^-4 mm³), providing a direct measure of surface fidelity. Mechanical testing of the lattice architectures revealed that the hexagonal design exhibited a compressive strength of 8.3 MPa, approximately six times higher than that of the truss-plate lattice (1.32 MPa), despite both possessing a similar porosity of 90%. This demonstrates that the lattice architecture plays a more dominant role than porosity in determining the overall strength. By integrating rheology-optics-mechanics into a shrinkage-controlled, architecture-optimized strategy, this study establishes generalizable design guidelines for high-fidelity, load-bearing ceramic lattices manufactured via DLP.