Centrifugal device and method for fluid component separation

A method of manufacturing a rotor for centrifugal separation of a composite fluid into components, comprising:

• providing a rotor comprising:
• a generally disc-shaped container housing having a spin axis, the container housing extending radially outwardly from the spin axis to an outer perimeter and rotatable about the spin axis to effect centrifugal separation of the composite fluid, and an aperture in an upper surface of the housing,
• a peripheral collection chamber within the housing and disposed radially outwardly from the spin axis toward the outer perimeter of the container housing, and
• a central collection chamber within the housing and located centrally about the spin axis and in fluid communication with the peripheral collection chamber, the collection chamber having a downwardly sloping inner surface and a closed bottom;
• depositing a volume of a separating material comprising a thixotropic gel on the inner surface of the central collection chamber;
• spinning the container housing about the spin axis for a time and at a speed sufficient to move at least most of the separating material into the peripheral collection chamber, wherein a film of the separating material remains on a first area of the central collection chamber while a second area of the central collection area remains free of the separating material, and wherein the first area of the film of separating material comprises a hydrophilic area having a greater surface energy, and the second area free of the separating material comprises a hydrophobic area having a lesser surface energy.

A method of separating a composite fluid into components, comprising:

• providing a rotor comprising:
• a generally disc-shaped container housing having a spin axis, the container housing extending radially outwardly from the spin axis to an outer perimeter and rotatable about the spin axis to effect centrifugal separation of the composite fluid, and an aperture in an upper surface of the housing,
• a peripheral collection chamber within the housing and disposed radially outwardly from the spin axis toward the outer perimeter of the container housing,
• a central collection chamber within the housing and located centrally about the spin axis and in fluid communication with the peripheral collection chamber, the collection chamber having a downwardly sloping inner surface and a closed bottom,
• the inner surface including at least one hydrophobic area having a first surface energy sufficiently low to provide a flow path for a lower density fluid component to flow to the closed bottom, and at least one hydrophilic area having a second surface energy greater than the first surface energy, and
• a separating material comprising a thixotropic gel disposed within the peripheral collection chamber and having a volume and density sufficient to form a barrier between the components of the composite fluid during centrifugal separation;
• disposing the composite fluid to be separated into the central collection chamber;
• spinning the rotor about the spin axis for a time and at a speed sufficient to separate the fluid into components, at least a first component forced into the peripheral collection chamber radially outwardly of the separating material, at least a second component remaining radially inwardly of the separating material;
• and
• stopping the spinning of the rotor, whereby the second component flows downwardly along at least the hydrophobic area of the inner surface to the closed bottom of the central collection chamber.