Provided herein is an artificial dielectric material comprising a plurality of layered sheets of a dielectric material and a plurality of conductive elements disposed in holes made in the sheets of the dielectric material, wherein each conductive element is substantially tubular and comprises a slit along its length so as to provide a gap between two longitudinal edges. Also provided are lenses comprising the artificial dielectric materials and methods for manufacture of such materials. The artificial dielectric materials and lenses may provide desirable dielectric and radio wave focusing properties and manufacturing advantages.