Conductive elastic composite

1. A conductive elastic composite that can be elastically stretched to >120% of its original length, without more than a 20% change in electrical resistance, comprising an elastomeric matrix, carbon nanotubes and carbon fibers;

wherein the carbon nanotubes are present in a concentration of less than 7% by weight, and the carbon fibers are present in a concentration of less than 4% by weight; and

wherein the carbon nanotubes have a diameter of approximately 10-20 nm and a length of approximately 5-20 microns, and further wherein the carbon fibers have a diameter in the range of 5-20 microns and a length greater than about 250 microns.

2. The conductive elastic composite of claim 1 , where the elastomeric matrix is selected from the group of consisting of natural rubber, epoxidized natural rubber, styrene-butadiene rubber, nitrile rubber, chloroprene rubber, ethylene propylene rubber, butyl rubber, chlorobutyl rubber, acryl rubber, silicone rubber, fluorine-containing rubber, butadiene rubber, epoxidized butadiene rubber, epichlorohydrin rubber, urethane rubber, polysulfide rubber, olefin-based elastomers, poly(vinyl chloride)-based elastomers, polyester-based elastomers, polyurethane-based elastomers, polyamide-based elastomers, polystyrene-based elastomers, other thermoplastic elastomers, and mixtures of the foregoing.

3. The conductive elastic composite of claim 1 , wherein the elastomeric matrix is a two-part urethane.

4. The conductive elastic composite of claim 1 , wherein the carbon nanotubes are multiwalled, with a purity of approximately 85% or greater.