Actuation of Magnetic Beads on a Complementary Metal–Oxide–Semiconductor Chip for Biological Applications

Magnetic beads with a diameter of 2.8 µm are actuated on a standard complementary metal–oxide–semiconductor (CMOS) chip. The chip was fabricated using the 180 nm process and has two groups of parallel current paths in the top metal layer and the second top metal layer. These two are placed diagonally to each other. Suspended beads were applied onto the chip and a magnetic field that was induced by patterned currents manipulated beads successfully. To observe an effect induced by a thermal convection flow, several current patterns were tested and the actuation of beads was examined. The result suggests that the beads were mainly driven by the magnetic field and partially affected by a convex flow generated by the current on the paths.