A medical electrode for obtaining biopotentials from the skin of a subject or electrically stimulating the subject's skin and deeper tissue layers. The electrode has a carrier base member from which project a plurality of spikes arranged in an array on one surface of the base member. The spikes are sufficiently long to penetrate through the stratum corneum into the stratum germinativum of the subject's skin. The spikes may be formed by a deep reactive ion etching process on a silicon wafer forming the base member. A fluid container may be formed on another surface of the skin for providing a drug to the surface of the skin through holes in the base member. The action of the spikes on the skin enhances administration of the drug.