The Georgia Institute of Technology and the Indian Head Division of the Naval Surface Warfare Center have developed a novel approach to the formation of nanoporous copper films. The approach is making it possible to literally fabricate an explosive device along with the circuitry of an IC. This technology in turn will make possible a new generation of smart MEMS (microelectromechanical-system) detonators for medium-caliber and smaller munitions for the US Navy.

Georgia Tech researcher Jason Nadler uses templates composed of microspheres or woven fabrics to impress a pattern on a copper-oxide/polymer paste. Nadler then removes the template and converts the paste to metallic copper through thermochemical reactions, retaining the physical pattern in the metal. The result is a uniform dot on the order of a millimeter in diameter with highly predictable pore size and density.

This dot, in turn, becomes the precursor for the formation of a dot of explosive material. Because the whole process is compatible with conventional semiconductor processing, the explosive can reside on the die with the circuitry that ignites it, forming a monolithic MEMS smart fuse measuring only a few millimeters on a side.

Such fuses will both increase the selectivity of small-caliber weapons and substantially reduce the use of toxic and unstable bulk explosives that would normally go into a much larger fuse assembly. Nadler believes there may be industrial applications for the copper-film-formation process, as well.