A shell size adjustable core–shell nano building block of SiO₂@TiO₂ using high refractive index materials of TiO₂ as shell to coat SiO₂ colloidal NPs by one step approach was prepared. Corresponding colloidal suspension of SiO₂@TiO₂ photonic crystals in propylene carbonate showed a highly adjustable structure color change with the high-refractive index upon applying of electric fields.

In this perspective, we evaluate CTE scaffolds manufactured using different biomaterials from the perspective of 3D printing strategies combined with their clinical use. The bionic structure and special functional designs are also discussed.

A soft structure with continuously variable stiffness and fast response was designed. Varying the electric field strength (0 to 4.5 kV mm ⁻¹ ), the rate of stiffness variation is over 1500%. The response time to load change is within 65 ms.