Multimaterial Metamaterials: Customize Targeted Thermal Deformation Modes Responding to Time- and Space-Variant Temperature Stimuli.

Customizing the engineering targeted thermal deformations is of vital significance for dimensional stability or shape morphing in materials and structures. However, current metamaterials are designed solely in the homogeneous form to respond only to the time-variant temperature (TVT) stimuli, far behind the practical engineering scenario and demands. Here, a new strategy is originally proposed and experimentally verified to design a series of both homogeneous and inhomogeneous multimaterial metamaterials, which uniquely output various thermal deformation modes, responding to time-variant and space-variant temperature (SVT) stimuli. Specifically, in addition to the regular isotropic thermal deformations, the metamaterials could exclusively output the entirely different positive and negative thermal deformations along the two orthotropic directions. Besides, stimulated by both TVT and SVT, the metamaterials provide more flexibility to customize the targeted thermal deformations. That is, the uniform thermal deformations could be well customized by the metamaterials stimulated by either TVT or SVT. More importantly, the customizability is remarkably broadened, as the nonuniform, specifically, mathematicized linear and nonlinear thermal deformations, are elaborately customized. Overall, these originally devised metamaterials open a new avenue for the purpose of customizing the engineering targeted thermal deformations in various modes under both TVT and SVT stimuli.