Figure 6.

Multiple sized bead separation in an iFCS device. (A) Averaged separation distance (number of experiments n=3) between diamagnetic beads and magnetic beads. Diamagnetic beads (20.3 μm, 8.0 μm, and 5.7 μm) and magnetic beads (11.8 μm) were spiked into a 0.292% (v/v) ferrofluid at variable sample throughput (10 – 350 μL/min). (B) Averaged separation distance (number of experiments n=3) between 8.0 μm diamagnetic beads and 11.8 μm magnetic beads at ferrofluid concentration between 0.01% and 0.1%, and throughput between 10 and 210 μL/min. (C) Bead trajectories of 8.0 μm diamagnetic beads (red) and 11.8 μm magnetic beads (yellow) at sample throughput of 100 μL/min. A ferrofluid with a concentration of 0.049% (v/v) was used. The green arrows indicate the flow direction. (D) In absence of magnetic fields, all beads (20.3 and 8.0 μm diamagnetic beads, and 11.8 μm magnetic beads) were randomly distributed in the channel at the outlets. (E) When magnetic fields were present, diamagnetic beads (20.3 and 8.0 μm) flowed into the top outlet. Majority of magnetic beads (11.8 μm) flowed into bottom outlet. (F) Image of collected beads from outlets. The red fluorescent signal was from 8.0 μm diamagnetic beads and the yellow fluorescent signal was from 11.8 μm magnetic beads. Gradient of magnetic field flux density was 132 T/m (at the center of the microchannel) in all figures. Scale bars in (C-F): 200 μm.