A novel magneto-mechanical metamaterial cell structure with large, reversible and rapid two-way shape alteration

Abstract

Smart mechanical metamaterials based on various types of stimuli-sensitive materials break through the limitations of traditional metamaterials and exhibit many attractive properties. The development of multi-functional mechanical metamaterials capable of multi-mode, reversible, large deformations and remote controllability remains a challenge. In this work, we designed and prepared several magneto-mechanical metamaterial unit cells based on magnetoactive soft materials using 3D printing technology. A novel cell structure of cuboctahedron was fabricated and examined deeply which was elongated or contracted along the central magnetic field direction under different external magnetic fields. Experiment and simulation results shown that the special metamaterial structure design enables the magneto-active unit cells to achieve super deformation characteristics that it does not originally possess. The rapid two-way large deformation of the cuboctahedron cell was achieved with a quite remarkable deformation up to 85%, and it could quickly return to the original shape of the cell when the magnetic field was removed. Besides of these capabilities, as an application example, we further demonstrated the multi-modal shape of shrinkage and elongation of the cell structure in a biomimetic blood vessel, to show the effectiveness of the prototype smart stent for particle transport in a remotely controllable manner. The developed magneto-mechanical metamaterial certainly can be extended to various functionalized application, such as soft robots, healthcare and flexible electronics.