principle is desirably aligned with respect to the axis of rotation 64 of rotor 70 the present invention contemplates a variety of configurations for pump 60 and rotor 70 as well as the placement and polarization of multiple passive bearing sets as at 81 u2014 81 and 82 u2014 82 to assist in the passive and stable suspension of rotor 70 within housing 61 the density of rotor 70 is relatively lower than that of the fluid being pumped in pump 60 such a low relative density of rotor 70 may preferably be achieved by providing rotor 70 as a hollow body in addition rotor 70 is preferably symmetrical in configuration such that both the passive magnetic forces and centrifugal forces acting thereon cancel each other out when rotor 70 is positioned at a centrally disposed origin of chamber 62 in preferred embodiments of the present invention pump 60 and specifically rotor 70 are preferably constructed of suitable bio compatible materials such as polycarbonate acrylic or copolymers of polystyrene alternatively a coating may be applied to a suitable substrate in order to enhance the biocompatibility of the structure however in applications wherein the device is not being employed for physiological implantation other materials may be employed most preferably however housing 61 and rotor 70 are fabricated from materials consistent with the handling of fragile or aggressive fluids as indicated in.