Microchips are provided to control both the rate and time of release of multiple chemical substances and allow for the release of a wide variety of molecules in either a continuous or pulsatile manner. Reservoir arrays are used to store and protect chemical sensors or potent drugs within the body for long periods of time. These arrays are designed for compatibility with preprogrammed microprocessors, wireless telemetry, or sensor feedback loops to provide active control. Individual device reservoirs can be opened on demand or on a predetermined schedule to precisely control drug release or sensor activation. The microchip delivery system consists of a substrate containing multiple reservoirs capable of holding chemicals in the solid, liquid or gel form. Each reservoir is capped (i.e. with a conductive membrane) and wired with the final circuitry controlled by a microprocessor. This central processor should be able to actively control electrically the exact time of release and the amounts of drugs dispersed by controlling the dissolution of the gold membrane. The system should be reasonable to manufacture by standard microfabrication techniques and still be cost-effective.