The deployment of 3-D morphing surfaces: A 2-D auxetic metamaterial approach through buckling-induced mechanism

The 3-dimensional shape morphing is desired in applications such as aerospace, soft robotics and medical devices. Via the arrangement of auxetic cells, this paper proposes a box-shaped morphing block concept consisting of 2-dimensional metamaterial to realize 3D shape morphing driven through the structural buckling approach. Firstly, the expansion, bending and twisting deformation modes of the morphing block distinguished by varied Poisson's ratio arrangement of the auxetic face cells on boundary lattices are introduced. Then, we verify the deployment of 3D deformation through a series of quasi-static tensile experiments, which present a good agreement with our simulation results and demonstrate the effectiveness of induced buckling mechanism. Finally, more complex morphing features are realized by a hybrid combination of the different deformation modes, while their deployment mechanisms are discussed. This morphing block concept with tailorable shapeshifting capability can be an excellent candidate in the 3D morphing structure application.