A conductive system and a method of forming an insulator for use in the conductive system is disclosed. The conductive system comprises a foamed polymer layer on a substrate. The foamed polymer layer has a surface that is hydrophobic, and a plurality of conductive structures are embedded in the foamed polymer layer. An insulator is formed by forming a polymer layer having a thickness on a substrate. The polymer layer is foamed to form a foamed polymer layer having a surface and a foamed polymer layer thickness, which is greater than the polymer layer thickness. The surface of the foamed polymer layer is treated to make the surface hydrophobic.