Electrodeposition in Structural Lattices of Variable Architectures

The development of approaches that can autonomously fill and heal material voids and yield composites with tailorable properties is increasingly relevant in engineering. Here, we experimentally and numerically investigate the potential of electrodeposition to engineer stainless‐steel lattice scaffolds with variable structures immersed in seawater. Applied voltages of 2–4 V for up to 168 h govern mineral composition, shifting precipitation from Ca‐enriched to Mg‐dominant. Deposits consist primarily of CaCO 3 and Mg(OH) 2 polymorphs, with the former accounting for ~21% of the mineral fraction at 2 V and the latter reaching ~92%–94% at 3–4 V. Lattices can gain up to 420 mg of minerals, ~135% of their untreated mass. The mineralization is enhanced at lattice boundaries, corners, and struts by geometry‐dependent electric‐field localization. Mechanically, electrodeposition reduces stress at 8% strain from 53.4 to 34.0 MPa in the small‐opening lattice, which shows a ductile response, while increasing peak stress from 11.7 to 13.5 MPa and residual stress from 4.9 to 10.1 MPa in the large‐opening lattice, which shows a brittle response. Altogether, the results of this work show that electrodeposition enables geometry‐sensitive, autonomous void filling, modification of chemical and mechanical properties, and the potential to grow architected composites with electricity.