Thermoresponsive multistable origami metastructures with tunable and sign-switchable Poisson's ratio

© 2025 Elsevier LtdIn recent years, origami-inspired structures with reconfigurable geometries and tunable mechanical properties responsive to external stimuli have garnered significant attention. In this work, we introduce a metastructure inspired by the Morph origami pattern, incorporating bilayer strips as thermoresponsive creases to enable the tuning of its mechanical properties via thermal stimulation. By exploiting the distinct thermal deformation behavior of the bilayer material system, the metastructure can reversibly switch between its eggbox and Miura-ori configurations under heating and cooling, respectively. By combining the bimaterial strip model with a chained beam constraint model, we develop an analytical predictive model to accurately capture the thermal bending response of the thermoresponsive creases and the resulting mechanical properties of the metastructure. Our findings reveal that the proposed metastructure offers a tunable Poisson's ratio with sign-switching capability. Additionally, its multistable behavior can be tailored through the manipulation of initial geometric parameters and regulated by temperature changes. The proposed metastructure holds potential for a wide range of engineering applications, including soft robotics and adaptive systems.