Abstract:
Architected materials typically derive their mechanical properties from continuous, rigidly connected networks of struts, plates, or shells. In this talk, I will introduce an alternative design paradigm based on discrete, topologically interlocked building blocks: polycatenated architected materials (PAMs). Inspired by chain mail, PAMs consist of rings, polygons, or polyhedral cages concatenated into three-dimensional networks derived from crystalline lattice topologies, with kinematic degrees of freedom set by particle geometry and catenation pattern. I will first describe our earlier work on two-dimensional interlocked fabrics, showing how jamming can be triggered by external confinement to reversibly and dramatically stiffen chain mail sheets, and how a modified Maxwell criterion predicts the in-plane and out-of-plane rigidity of torus-knot tessellated fabrics from their connectivity alone. Building on these principles, I will present a general design framework that translates arbitrary crystalline networks into three-dimensional polycatenated particle assemblies. Under small loads, PAMs behave like non-Newtonian fluids, exhibiting both shear-thinning and shear-thickening responses; at larger strains, they jam into solid-like lattices with nonlinear, hysteretic stress-strain behavior reminiscent of granular media. I will show that this fluid-solid duality, along with the critical jamming strain, can be programmed through particle geometry and catenation topology, and that it persists across length scales, from centimeter-scale printed samples to micron-scale structures whose shape can be reversibly reconfigured using electrostatic forces. Together, these results establish PAMs as a new class of architected materials that bridge discrete granular physics and continuum architected-materials design, opening routes toward stimuli-responsive, energy-absorbing, and shape-morphing systems.
Host: Xiaoyue Ni & Cate Brinson
Event Series
DMI Seminar Series