Tunable hybrid metasurfaces for MRI applications

One of many exciting application of metasurfaces is in the magnetic resonance imaging (MRI). Here we demonstrate theoretically and experimentally how to improve substantially the MRI sensitivity by employing the concept of hybrid metasurfaces. We design a novel hybrid metasurface as an array of nonmagnetic metallic wires with high permittivity dielectric blocks at the edges. We demonstrate that tunability of this metasurfacc can be achieved via a change of the effective permittivity of blocks near the edges. Moreover, altering the coupling strength between the dielectric and metallic elements allows to obtain nearly homogeneous shapes of the near-field magnetic modes.