Electrically tunable negative permeability metamaterials based on electrorheological fluids

We experimentally studied the effects of certain factors, such as the ways of loading of electrodes, the concentration of ER fluids, the type of ER fluids and intensity of applied electric fields, on the resonant frequency of split-resonant ring array infiltrated in ER fluids. The experimental results show that the way of loading of electrodes has important effects on the magnetic resonance of SRR array. The resonant frequency of SRR array shows a red-shift when the ER fluid is infiltrated, the maximum shift of about 130 MHz was obtained through the adjustment of the applied electric-field. Numerical simulation demonstrates that the permeability of SRR array is negative near the resonant frequency, and the frequency range of negative permeability can be dynamically tuned by the applied electric-field.