Figure 7.

Arrangement of micropatterns. A, Isolation is performed via lateral magnetophoresis induced by a high‐gradient magnetic separator, a ferromagnetic wire array inlaid in the bottom substrate of a microchannel. ⁸⁸ B, The principle of CTC separation by lateral magnetophoresis is based on a V‐shaped ferromagnetic wire array in the microfluidic system. ⁹⁸ C, When the blood sample flows through the microchannel, CTCs are attracted to permanent magnets, which are placed outside the channel and trapped by thin‐film micromagnets on the channel substrate, whereas normal blood cells are unaffected and flow out of the channel. ⁹⁹ D, The trapezoidal solenoid produces a focused magnetic field that captures CTCs on micromagnets at the center of the channel. ¹⁰⁰ E, Inkjet printing can deposit a defined magnetic pattern on any substrate to facilitate CTC isolation. ¹⁰¹ F, The paramagnetic strips produced by molding enhance the efficiency of isolation ¹⁰²