Abstract
MHD micropump with AC current and permanent magnet is studied. In order to achieve continuous flow, AC current is modulated. A lumped parameter system for the objective pump is numerically analyzed. When AC current is applied for one cycle and is ceased, the fluid in the pump flows in one direction due to the fluid momentum in the case of turbulent flow resistance. However in the case of laminar flow resistance, the driven fluid returns to the starting point. If the fluid viscosity can be temporally controlled by addition of extra AC current, the fluid in the pump can flow in one direction even in the case of laminar flow resistance.