A microfluidic delivery system (10) includes a reservoir (3) to hold a predetermined volume of fluid, such as a dose of a drug. An outlet (5) allows delivery to a patient. A piston (15) can move in the reservoir (3) to dispense fluid through the outlet (5). Movement of the piston (15) is provided by an actuator (9) including a coil (19) of shape memory allow. Other examples use SMA wires. The SMA element (19) is controlled by an electrical current.
