US Patent 10443738 Magnetic fluid seal for implantable devices

Systems and methods for providing a magnetic fluid (MF) seal suitable for a fluid environment may provide a shaft and a magnet that is cylindrical or ring-shaped. A magnetic fluid may be present between the magnet and shaft. Additionally, pole pieces may also be provided, which are also cylindrical or ring-shaped. These pole pieces are positioned on the shaft so the magnet is sandwiched between the pole pieces. The magnet, pole pieces, and shaft, if magnetic, may attract and retain the magnetic fluid in an annular gap or region between the shaft and the magnet and/or the pole pieces. The magnetic fluid in the annular gap serves as a seal or barrier that prevents fluid from passing through when pressure is below a predetermined level.