Manipulation of magnetic particles on chip by magnetophoretic actuation and dielectrophoretic levitation

The prospect of using magnetic particles for biomedical purposes in lab-on-a-chip systems compels accurate and flexible particle manipulation. Toward such a goal we designed a microdevice comprising a pair of meander-shaped current carrying conductors, which enable simultaneous magnetophoresis and dielectrophoresis by generating both a traveling magnetic field and an ac electric field. Therefore, both the in-plane and out-of-plane movements of magnetic particles can be electrically controlled. A transport speed of tens of mu m/s was achieved with actuation forces at piconewton scale. The enhanced control of particle movement avoids the contact and nonspecific adhesion between the particle and device. (c) 2007 American Institute of Physics.