Cage-shaped self-folding mechanical metamaterials

Abstract

Self-folding is an effective design method for mechanical metamaterials with complex configurations and multiple material components. However, existing self-folding mechanical metamaterials are typically limited to a single transformation, limiting their potential for various deformation modes and diverse application scenarios. In this paper, we present a cage-shaped, self-folding mechanical metamaterial. This metamaterial exhibits multiple deformation modes from an initially flat state upon heating to different temperatures and subsequently remains stable upon cooling. The constituent self-folding elements of the metamaterial comprise temperature-responsive materials to achieve different folding thresholds. Theoretical models are developed to quantify the mechanical properties of the metamaterial, enabling programmable design of its mechanical performance. We also demonstrate that the cage-shaped mechanical metamaterial has tunable mechanical properties, multi-stage load-bearing, and decoupling of mechanical performance, providing the possibility of multifunctional applications in various fields.