. . "Substrate 34 may be formed of a conductive, nonconductive, semiconducting material, or the like, and may comprise glass, silica, alumina, plastic or other organic polymers for example acrylonitrile-butadine-styrene copolymers, polysulfone, polystyrene, metals, or any of the above materials described with respect to material 32 of the present invention." . . . . . .