Magnetohydrodynamic pump

A method of operating a magnetohydrodynamic (MHD) device,

• the MHD device comprising:
• an electrochemical cell comprising a first electrode, a second electrode, and an enclosed gas volume;
• an aqueous liquid between the first electrode and the second electrode;
• and
• a magnet,
• the method comprising:
• generating a reaction gas at a first rate on the first electrode;
• consuming the reaction gas at a second rate on the second electrode, the first rate being substantially equal to the second rate;
• fluidly connecting the first electrode and the second electrode via the enclosed gas volume;
• generating a current having a direction in the aqueous liquid with the electrochemical cell;
• generating a magnetic field having a direction normal to the direction of the current with the magnet;
• and
• producing a propulsive force having a direction simultaneously normal to the direction of the magnetic field and the direction of the current.