A micropump that pumps liquid using electrothermally-induced flow is described, along with a corresponding self-regulating pump and infusion pump. The micropump has applications in microfluidic systems such as biochips. The self-regulating infusion pump is useful for the administration of large and small volumes of liquids such as drugs to patients and can be designed for a wide range of flow rates by combining multiple micropumps in one infusion pump system.