Figure 1.

The hydrofoil located at the downstream of a spiral microchannel and the working principles of the hydrofoil. Circulating tumor cells (CTCs) (red dots) and white blood cells (WBCs) (blue dots) are pre-focused about their respective equilibrium positions separated at a distance of s_p,u via a spiral channel at the upstream. The hydrofoil affects the stream, such as to increase the separation distance between the CTC and the WBC streams at the downstream to s_p,d, which is large enough to direct the separated streams to CTC and WBC channels at the downstream separated by a separation wall. The length of the scale bar is 3 mm.