Electrical contact between metals of different resistivities.

摘要

In an electrical device comprising first and second members having different resistivities, a thin contact layer of intermediate resistivity is provided between the first and second members. The contact layer (30), (which may comprise a conductive polymer) is intimately bonded to the member of highest resistivity (which may comprise a second conductive polymer) e.g., by a printing process. The member of lowest resistivity may comprise a third conductive polymer, in which case it may be intimately bonded to the intermediate contact layer, e.g. by a printing process, or it may comprise a metallic member, in which case good electrical contact may be made merely by pressing the metallic member (15, 16) against the contact layer even when the contact area is large and/or long, and even when the pressure is sufficiently low to permit, if necessary, relative movement of the metallic member and the contact layer without disrupting the bond between the contact layer and the resistive element. A preferred device comprises four or more members of different resistivities. The members are arranged adjacent each other in order of decreasing resistivity. The least resistive member preferably comprises a metal and the other members conductive polymer materials.