A heat sink uses a pump assembly to generate a magnetic field. A direction of electrically and thermally conductive liquid flowing through the pump assembly is dependent on an orientation of the magnetic field and the direction of electrical current induced across flowing fluid in the magnetic field. In such a manner, cool liquid may be directed toward a heat source and warmer liquid may be directed to flow away from the heat source, where heat transfer occurs between the liquid and the heat sink. Additional pump assemblies that generate separate magnetic fields may be used to increase fluid flow volume, thereby increasing heat transfer away from the heat source.