Tuning of photonic bandgaps by a field-induced structural change of fractal metamaterials.

Bandgaps of a structure with electrorheological fluids sandwiched between planar metallic fractal electrodes are investigated in the microwave regime. Our results show that bandgaps are tunable as a result of the electrorheological effect induced by the external electric field applied directly to the structure. A finite-difference time-domain simulation reveals that the tunability of bandgaps is not related to the average dielectric constant but is caused by the field-induced structural change in the electrorheological fluids.