Ruthenium and ruthenium dioxide, an electronic conductor, have been evaluated as electrical contact materials for low voltage, low force contacts, and separable connectors. The contact resistance (CR) of bulk RuO2 is 1 mΩ, only slightly higher than that of gold or ruthenium. A technologically more feasible contact, titanium coated with RuO2, has been developed and has a CR of less than 15 mΩ. Environmental studies show that both Ru and RuO2 are reasonably stable at temperatures at least as high as 90° C and at all relative humidities, even in the presence of 1 ppm H2S or flowers of sulfur vapor. Unlike other contact materials, sulfidation appears to be retarded by the presence of a high relative humidity. © 1979, The Electrochemical Society, Inc. All rights reserved.