Why must a fluid conduct electricity for an electromagnetic pump to work?

An electromagnetic pump requires a fluid to be an electrical conductor because the pump operates on the principle of the Lorentz force, which is the same principle used in an electric motor.1

To generate the necessary force to move the fluid, the pump passes an electric current crosswise through the fluid while it is positioned within a magnetic field. Because the current represents a flow of moving charges, the magnetic field exerts a force on these charges, which is then transferred to the fluid itself, pushing it in the direction of the flow. If the fluid were not electrically conductive, it would be impossible to pass this current through it, and consequently, no electromagnetic force could be generated to drive the pumping action. This technology is primarily used for pumping liquid metals, such as those utilized for cooling nuclear reactors.12