Drug delivery devices, sensors, and micropumps provided herein can utilize a reaction of an analyte triggered by an enzyme to drive fluid flow. In some cases, a drug delivery device can include a reservoir including a drug (e.g., insulin) and have an enzyme (e.g., glucose oxidase) positioned adjacent to said reservoir. The enzyme can catalyze a reaction of said analyte to drive a fluid flow adjacent to said reservoir to increase a release of the drug from said reservoir. A sensor for an analyte can include an enzyme bound to a surface and a flow meter to detect a flow of fluids adjacent to said surface. A self-powered enzyme micropump provided herein can provide precise control over flow rate in response to specific signals.
