Described herein are systems, devices, and methods for the delivery of substances to, or the sampling of substances from, a patient using a portable and preferably implantable device. The substances introduced to and/or taken from the patient are preferably fluidic and are driven by a miniature pump, such as a microimpedance pump. A number of design variations are explicitly and implicitly described, such as the use of multiple pumps and multiple reservoirs for containing medicaments. Methods of manufacture of these systems and devices are also described, for instance, using molding, micromachining, or lithographic processes.