Casimir repulsive-attractive transition between liquid-separated dielectric metamaterial and metal

Herein, the repulsive-attractive transition, regarded as a stable equilibrium, between gold and dielectric metamaterials (based on Mie resonance) immersed in various fluids was studied. This transition is owing to the interplay of the gravitational, buoyant, and Casimir forces among different geometries containing parallel plates and spheres levitated over substrates. It was found that Mie metamaterials allowed a wider range of separation distance for stable equilibrium than was possible with natural materials. The relationship between the separation distance for stable equilibrium and the constructive parameters of the Mie metamaterial and the geometric parameters of the system was investigated, and simple rules for tuning the equilibrium position by modifying the constructive parameters of the Mie metamaterial was provided. These results are promising for potential applications in frictionless suspension in micro/nanofabrication technologies.