Mechanical response and dimensional accuracy evaluation of SLA elastomeric lattice structures based on buckling simple and body-centered cubic cell topology

This study presents the design, fabrication, and comprehensive characterization of polymeric lattice structures with tunable mechanical behaviour. These structures enable control of macroscopic mechanical properties through specific geometrical parameters. A parametric unit cell was developed defining three independent variables governing the overall deformation response. Two different types of lattice structures, simple cubic and body-centered cubic, were studied and designed into crystalline-inspired configurations, resulting in eight different lattice geometries. Fabrication was performed via VAT photopolymerization using stereolithography technology with a transparent biomedical elastomeric resin, specifically selected for its high ductility and strain tolerance up to 150%. A dimensional accuracy analysis was conducted to quantify geometric fidelity and manufacturing stability. Mechanical characterization involved uniaxial compression tests to evaluate scalability, stiffness and energy absorption capacity, exploring cyclic loading conditions. In addition, the possibility of tuning the Poisson’s ratio of the lattices was quantified by measuring the transverse-to-axial strain ratio under compressive strain. The combination of geometry and elastomeric material behaviour enabled the obtainment of lightweight structures capable of sustaining large deformations reversibly, absorbing (EAbs = 302 [mJ/g]) and dissipating energy (ELost = 60 [mJ/g]), exploiting the potential applications as energy-absorbing materials. SLA manufacturing deviations constrain cell mobility and alter lattice stiffness. Cell topology governs buckling interactions and the macroscopic compression response. Reduced cell constraints promote compliant deformation and low Poisson values. FE modelling separates topology driven mechanics from manufacturing induced effects.