Breaking the limitation of terahertz resonances in ferrites through 4D printing of metamaterials

4D printing allows the creation of 3D-printed structures with a variety of new functionalities that respond to external stimuli, including electromagnetic properties, for which research is limited, such as terahertz resonances in ferrite materials; and therefore holding great promise for a wide range of applications. However, the limited physical properties of ferrite materials, including their anisotropic properties and limited material manipulation space, pose significant challenges to the development of ferrite materials designed for progressively increasing terahertz frequencies. Therefore, this paper proposes a platform for overcoming the limitations of terahertz resonance in ferrites through the 4D printing of metamaterials. Both the elastic and viscous moduli of the slurry are sensitive to the applied shear stress; as this stress increases, these moduli sharply decrease by several orders of magnitude, resulting in the transformation of the slurry into a fluid state similar to the liquefaction of ink. Electromagnetic coupling modes between electric dipoles and magnetic dipoles endow these ferrite metamaterials with induction and switching of terahertz resonances due to orientation stimulation. Our work sheds light on the creation of electromagnetic properties and their control by 4D printing.