Porous materials with well-defined periodicity are commonly encountered in biological and synthetic structures and exhibit a wide range of behaviors, ranging from negative Poisson’s ratios, to high energy absorption and acoustic damping. Recently, the response of these systems has been shown to be enhanced by mechanical instabilities that lead to sudden and reversible geometric transformations. Although buckling induces planar transformations in most of 2D porous metamaterials, here we describe the emergence of 3D morphologies triggered by mechanical instabilities in an elastomeric block with tilted cylindrical holes. As a proof of concept, we demonstrate that these structures can be leveraged to tune surface properties including friction and light reflection, thus providing a new experimental platform for investigating deformation-dependent dynamics for tribological and optical applications.

具有明确周期性的多孔材料在生物和合成结构中很常见，并且表现出广泛的行为，从负泊松比到高能量吸收和声阻尼。最近，这些系统的响应已被证明会因机械不稳定性而增强，这些不稳定性会导致突然和可逆的几何变换。尽管屈曲会在大多数 2D 多孔超材料中引起平面变换，但在这里我们描述了由具有倾斜圆柱孔的弹性体块中的机械不稳定性引发的 3D 形态的出现。作为概念证明，我们证明可以利用这些结构来调整表面特性，包括摩擦和光反射，