Metal-infiltrated BaTiO 3 lattices: a design-driven approach for improved energy conversion

Abstract Additive manufacturing enables the design of architected piezoelectric materials with tunable geometry and capacitive enhancement. In this work, field’s metal (FM) (32.5% Bi, 51% In, 16.5% Sn) infiltration was introduced as a novel strategy to enhance overall dielectric capacitance and charge transport within 3D-printed barium titanate (BTO) lattices. A 40 vol% BTO photopolymer resin (BT40) was formulated for digital light processing to fabricate 3D gyroid architectures with different controlled porosities. Following debinding and sintering to 96% theoretical density, and thermal poling ( d ₃₃ ≈ 120 pC N −1 ), the lattices were infiltrated with molten FM below the BTO Curie temperature (∼125 °C), forming continuous metallic networks. Rheological and optical analyses confirmed shear-thinning behavior and suitable curing depth for high-fidelity printing, while thermal and microstructural characterization verified complete binder burnout and tetragonal phase formation. Metal infiltration increased capacitance and conductivity by approximately two and three orders of magnitude, respectively, compared to non-infiltrated lattices. The 25% solid-fraction FM infiltrated gyroid achieved the highest performance, exhibiting approximately 80 times greater capacitance, 8000 times higher conductivity, and 64% higher upper-bound piezoelectric power density than bulk BTO. These findings demonstrate that FM infiltration of architected piezoceramic lattices enables simultaneous improvement of charge storage, transport, and energy conversion figure of merit at the materials level, offering a promising materials platform to improve the processing-architecture-processing relationship, impacting future sensing, smart-infrastructure and energy-harvesting devices.