MAGNETIC-BASED ACTUATION MECHANISMS FOR AND METHODS OF ACTUATING MAGNETICALLY RESPONSIVE MICROPOSTS IN A REACTION CHAMBER

1 .- 98 . (canceled)

99 . A method of processing a fluid, comprising:

providing a microfluidics system comprising:

at least one microfluidic device comprising a reaction chamber, wherein the reaction chamber comprises a micropost field, wherein the micropost field comprises surface-attached magnetically responsive microposts; and

at least one magnetic-based actuation mechanism provided in close proximity to the magnetically responsive microposts, wherein the at least one magnetic-based actuation mechanism is configured to generate an actuation force sufficient to compel at least some of the magnetically responsive microposts to exhibit motion, wherein the at least one magnetic-based actuation mechanism comprises one or more movable disc- or cylinder-shaped magnets, one or more plate magnets, one or more metal plates, one or more magnetic shields, or combinations thereof;

loading or flowing a fluid to be processed into the reaction chamber; and

applying an actuation force to the microposts via the magnetic actuation mechanism such that at least some of the microposts are compelled to exhibit motion, wherein the fluid is stirred or caused to flow or circulate in the reaction chamber.

100 . The method of claim 99 , wherein the magnetic actuation mechanism is a movable actuation mechanism, and optionally wherein the actuation force is a time-varying actuation force provided by a moving magnetic field produced by moving the movable magnetic actuation mechanism.

101 . The method of claim 99 , comprising enhancing diffusion in the fluid while inhibiting long range fluid transport.

102 . The method of claim 99 , comprising optimizing the flow of the fluid from the top of the reaction chamber to the bottom of reaction chamber.

103 . The method of claim 99 , comprising optimizing lateral flow of the fluid along a determined axis of the reaction chamber.

104 . The method of claim 99 , wherein at least a portion of the microposts are knocked down when the fluid is loaded or flowed into the reaction chamber, and the actuation force is applied such that at least some of the microposts that were knocked down by the fluid are returned to the substantially upright or vertical position.

105 . The method of claim 99 , further comprising applying an actuation force to the microposts via the magnetic actuation mechanism prior to the loading or flowing, wherein at least some of the microposts are held in the substantially upright or vertical position while the fluid is loaded or flowed into the reaction chamber.

106 . The method of claim 99 , further comprising applying an actuation force to the microposts via the magnetic actuation mechanism prior to the loading or flowing wherein at least some of the microposts are held in the substantially upright or vertical position while the fluid is loaded or flowed into the reaction chamber whereby Taylor dispersion within the fluid is reduced or eliminated.

107 . The method of claim 99 , comprising generating local circulation and bulk circulation of the fluid within the reaction chamber.

108 . The method of claim 99 , wherein the at least one magnetic-based actuation mechanism further comprises one or more magnetic shields arranged in a plane between the at least one magnetic-based actuation mechanism and a plane of the micropost field, and wherein applying the actuation force comprises moving the one or more magnetic shields to selectively allow the magnetic field of the at least one magnetic-based actuation mechanism to reach a portion of the surface-attached magnetically responsive microposts or to block the magnetic field of the at least one magnetic-based actuation mechanism from reaching a portion of the surface-attached magnetically responsive microposts.

109 . A microfluidics system comprising:

at least one microfluidic device comprising a reaction chamber, wherein the reaction chamber comprises an active surface, wherein the active surface is magnetically responsive; and

at least one magnetic-based actuation mechanism provided in close proximity to the active surface, wherein the at least one magnetic-based actuation mechanism is configured to generate an actuation force sufficient to activate the active surface;

wherein the at least one magnetic-based actuation mechanism comprises one or more movable disc- or cylinder-shaped magnets, one or more plate magnets, one or more metal plates, one or more magnetic shields, or combinations thereof.

110 . The microfluidics system of claim 109 , wherein the at least one magnetic-based actuation mechanism is a stator-based actuation mechanism comprising a stator ring supporting a plurality of magnetic poles, a bearing, and a diametrically magnetized (DM) magnet, wherein the stator ring and the magnetic poles are configured to be held stationary while the DM magnet is configured to move with respect to the magnetic poles, the DM magnet being constrained within the stator ring and the bearing.

111 . The microfluidics system of claim 110 , wherein the DM magnet is a DM ring magnet, and wherein the at least one microfluidic device is configured to be fitted into an opening of the DM ring magnet such that magnetic force from the DM ring magnet is in the plane of the microfluidic device.

112 . The microfluidics system of claim 109 , wherein the at least one magnetic-based actuation mechanism is configured to (i) hold the active surface in a substantially upright or vertical orientation while fluid is loaded or flowed into the reaction chamber and/or (ii) return the active surface to a substantially upright or vertical orientation after being displaced by fluid loaded or flowed into the reaction chamber.

113 . The microfluidics system of claim 112 , wherein the at least one magnetic-based actuation mechanism comprises an axially magnetized magnet, a pair of stationary plate magnets arranged on opposite sides of the microfluidic device, a plate magnet and a metal plate arranged on opposite sides of the microfluidic device, or a horseshoe magnet, each positioned such that the magnetic flux density is in the Z dimension relative to the plane of the active surface.

114 . The microfluidics system of claim 112 , wherein the at least one magnetic-based actuation mechanism comprises one or more plate magnets and the microfluidics system is enclosed in a magnetic shield, the magnetic shield being magnetized such that magnetic field lines from the one or more plate magnets are directed in a direction with the magnetic flux density in the Z dimension.

115 . The microfluidics system of claim 109 , wherein the at least one magnetic-based actuation mechanism comprises one or more movable disc- or cylinder-shaped magnets oriented sideways with respect to the microfluidic device such that the axis of rotation of:

each of the one or more magnets is substantially parallel to the plane of the active surface, and wherein the one or more magnets are configured to be moved back and forth through 180° to oscillate the magnetic flux density with respect to the active surface along the X or Y dimension of the reaction chamber.

116 . The microfluidics system of claim 115 , wherein the at least one magnetic-based actuation mechanism is configured to (i) enhance diffusion in a fluid within the reaction chamber while inhibiting long-range fluid transport, (ii) optimize flow of a fluid from the top to the bottom of the reaction chamber, or (iii) optimize lateral flow of a fluid along a desired axis of the reaction chamber

117 . The microfluidics system of claim 109 , wherein the at least one magnetic-based actuation mechanism comprises one or more magnetic shields arranged in a plane between the at least one magnetic-based actuation mechanism and the plane of the active surface, the one or more magnetic shields being movable and configured to selectively allow the magnetic field of the at least one magnetic-based actuation mechanism to reach the active surface or to block the magnetic field of the at least one magnetic-based actuation mechanism from reaching the active surface.

118 . The microfluidics system of claim 109 , wherein the at least one magnetic-based actuation mechanism is movable, the at least one magnetic-based actuation mechanism further comprising one or more magnetic shields at least partially surrounding the at least one magnetic-based actuation mechanism, the one or more magnetic shields being attached to and configured to move with the at least one magnetic-based actuation mechanism.