High Strength, Low-Density Mechanical Metamaterials Through DNA-based Self-Assembly

Nanostructured 3D hierarchical lattice materials might exhibit high mechanical strength at low density due to a combination of architecture and nanoscale size effects. DNA-based self-assembly enables a bottom-up fabrication of highly programmable superlattice structures with nanoscale features and designed architecture. 3D DNA voxels, formed through the prescribed folding of single-stranded DNA, can further assemble to yield a variety of superlattices, including simple cubic, diamond cubic and body centered cubic structures. These DNA lattices then serve as a scaffold for templating a diverse array of metal and metal oxides to form 3D nanostructured ceramic and composite nanomaterials. In this work, we explore the influence of fundamental superlattice design elements on mechanical properties through in-situ nanoindentation integrated with scanning electron microscopy (SEM). We investigate how superlattice architecture, inorganic coating, lattice defects, and crystal morphology influence ductility, deformation modes, compressive strength, and fracture mechanisms. This work highlights DNA self-assembly as a viable pathway to tunable, high-strength, low-density multifunctional ceramic materials.