Blood sealing properties of magnetic fluid seals

Shaft seals for rotary blood pumps have strong demands for low friction, very little leakage, and long-term use. Magnetic fluid seals have attracted attention as promising candidates for this purpose owing to their properties of having zero leakage, no wear, and relatively small viscous friction at the same time. In this study, the sealing performance including the maximum sealing pressure and the sealing durability under blood sealing is discussed. In addition, hemolysis tests for blood sealed by magnetic fluids are performed from the viewpoint of biological compatibility. The magnetic fluid seals are found to have adequate sealing durability and pressure resistance in the blood. In addition, hemolysis of blood sealed with the organic-solvent magnetic fluid seals is maintained below 0.5%.