Micropump (10) including a support structure (14), a pump tube (16), and an actuation system (18) comprising one or more pump chamber actuators (28), the pump tube comprising a pump chamber portion (24) defining therein a pump chamber (26), an inlet portion (20) for inflow of fluid into the pump chamber, and an outlet portion (22) for outflow of fluid from the pump chamber. The inlet, outlet and pump chamber portions form part of a continuous section of tube made of a supple material. The one or more pump chamber actuators are configured to bias against the pump chamber portion to expel liquid contained in the pump chamber via the outlet portion, respectively to bias away from the pump chamber portion to allow liquid to enter the pump chamber via the inlet portion. The pump chamber portion has a cross-sectional area Ap in an expanded state that is larger than a cross-sectional area Ai of the pump tube at the inlet and outlet portions.