Unidirectional transport of superparamagnetic beads and biological cells along oval magnetic elements

Precise movement control is a key feature for the use of superparamagnetic microbeads in medical and biological lab-on-chip applications. We demonstrate the unidirectional transport of magnetic and biological carriers along a chain of oval shaped magnetic thin film elements by in-plane rotating magnetic fields, enabling controllable manipulation and separation schemes. The same fundamental unidirectional movement is realized independent of the sense of magnetic field rotation and orientation of the magnetic pathway. The flowless directional transport of magnetically labeled rat embryonic fibroblasts is presented, validating the applicability of the structures for biological purposes. The lined up ferromagnetic structures are a critical building block for the construction of flexible pathways for biological lab-on-a-chip applications.