Superconductors Superconductors are materials that have no resistance to the flow of electricity. Even insulators (e.g. ceramics) can be made to superconduct under the right conditions. Applications are numerous; vehicles can "float" on strong superconducting magnets, production of non-invasive images of the human body with Magnetic Resonance Imaging (MRI), efficient generators made with superconducting wire, and the transmission of power to cities (due to the cost and impracticality of cooling miles of superconducting wire, this has to-date only happened with short "test runs").