Full text loading...
Schematic configurations of the three microcoil designs. The arrows represent the movement of magnetic beads when currents are sequentially switched on through the microcoils of each design.
Shifting magnetic beads between two interdigitated meander microcoils by injecting currents into each microcoil either alternatively or of different values: (a) Magnetic force profile along the device surface, and (b) magnetic beads transport between two interdigitated meander microcoils by alternatively injecting currents into each microcoil. The left photo shows the (1,0) mode, when are injected into the inner coil (Coil 1) while no current is injected into the outer one (coil 2), and the magnetic beads aligned along the wires of coil 1 (i). After switching on the current only in the outer coil, i.e. (0,1) mode, the beads released from the inner coil followed the newly established magnetic well and aligned along the wires of the outer coil (ii). For clarity, the insets schematically represent both cases. and flow rate .
Beads manipulation for distances of about by alternatively injecting currents into two sets of microcoils with loops and central magnetic pillars: (a) The profile of the magnetic force exerted on a magnetic bead with a radius by two independent conductor loops carrying current intensities of 100 and , respectively, and (b) when a current is injected in the left row, local maxima will be created at the center of each loop of the row and the magnetic beads will be trapped there (i). By switching on the current flow through the other set, the local maxima shift toward the center of these loops and the magnetic beads will move correspondingly (ii). and .
(a) Surface profile of the magnetic force due to two microcoils carrying currents of 100 and , respectively, and exerted on a bead with a radius, and (b) Magnetic beads transportation along an array of three spiral microcoils sequentially operated with triphazic signals. Due to the limitation of the microscope objective’s field of view and the large size of the spiral microcoils, only two of the three microcoils are visible. When a current is injected in the first spiral, a magnetic energy density maximum is created at the magnetic pillar located at its center and therefore magnetic beads are collected there (100 mode). Then the first spiral microcoil is switched off and the current in the second one is switched on, so that the magnetic gradient maximum shifts toward the corresponding pillar of the second microcoil and the beads will follow it (010 mode). The process is repeated for the third spiral microcoil (001 mode). In the 0 mode, the coil may carry a small value of current for magnetizing the beads in its vicinity. and .
Article metrics loading...