Elastic Rod Origami (RodOri) for Programming Static and Dynamic Mechanical Properties

Abstract: Reconfigurable mechanical systems enable precise programmable control over structural properties, opening new opportunities in architected materials, adaptive devices, and multifunctional structures. Here, we introduce elastic rod origami (RodOri), a platform that exploits remarkably simple elements (pre-stressed, naturally curved rods) into a system with an extraordinary degree of multistability and configurational richness. For example, a single 6-rod RodOri unit can easily access 11 distinct configurations, far exceeding the reconfigurability of conventional origami or general mechanical reconfigurable systems. Individual rods, constrained under clamped boundary conditions, undergo snapping transitions between discrete morphologies whose strain energy and stiffness are precisely prescribed by their natural curvature. Assembling these rods into modular multi-rod architectures yields metamaterials with numerous stable configurations that can be selectively and reversibly programmed. This configurational diversity enables tunable static stiffness, nonlinear force response, and thus enables tunable dynamic behaviors such as vibration filtering, wave-propagation switching, and mode conversion within a single, easily-manufactured platform. By leveraging curvature-induced mechanical instability, RodOri unlocks highly programmable static and dynamic mechanical behavior, offering new design strategies in reconfigurable structures, soft robotics, medical devices, and adaptive materials.