Abstract: A method of forming thin porous layers of calcium phosphate upon a silicon wafer surface using a high voltage spark. The outer layer of calcium phosphate is the inorganic component of bone and is anchored to the underlying substrate of silicon. The silicon is compatible with existing integrated circuit processing methods. The morphology and thickness of the calcium phosphate film can be controlled by the duration of the spark and the distance between the affected surface and the counterelectrode utilized. The resultant porous layer can be impregnated with medicinally useful substances which then can be subsequently released to the surroundings through an electrical actuator.