Embodiments of a system including a remotely controlled substance delivery device and associated controller are described. Methods of use and control of the device are also disclosed. According to some embodiments, a delivery device or related device may be placed in an environment in order to pump a material into the environment or into an additional fluid handling structure within the device. Exemplary environments include a body of an organism, a body of water, or an enclosed volume of a fluid. The concentration of a substance in the fluid to be delivered may be modified by a remote control signal. In selected embodiments, a magnetic field, an electric field, or electromagnetic control signal may be used.