A portable axial-flow polymer bridge pump with hydrodynamic bearings has been developed for bridge-to-bridge use. The pump is inexpensive to manufacture and disposable. It weighs 185 g and was verified to have a lifetime of 3 months with silent operation. For partial circulatory assist at a flow rate of 2 L/min, the clinical limit of hemolysis was verified for a rotational speed below 9000 rpm, at which a pressure of 100 mmHg was generated. In an anti-thrombogenic test, the pump stably operated for 6 h without thrombus formation.