Self-assembled ultra high strength, ultra stiff mechanical metamaterials based on inverse opals

Abstract

Researchers show that mechanical metamaterials based on ceramic inverse opaline structures with densities in the range of 330-910 kgm-3 are suitable as photonic crystals and have better stiffness- and compressive strength-to-weight ratios as compared to microfabricated optimized strut-based structures. The stiffness- and compressive strength-to-weight ratios are also lower than carbon nanoframes fabricated by interference lithography. Pure silica inverse opal structures and silica inverse opals whose pores have been internally coated by a thin TiO2 layer have been fabricated and their structural and mechanical behavior has been investigated.