TI Magnetophoretic Capacitors for Storing Particles and Cells in a Tri-Axial Magnetic Field

One of the main goals in the field of lab-on-a-chip is the manipulation of microparticles and cells on microfluidic chips. Methods based on magnetic forces, with remote controllability over particle movement, are considered one of the most appealing techniques toward this goal. Recently, inspired by electronic circuits and to transport particles in a controlled fashion in a tri-axial magnetic field, magnetophoretic circuits based on TI-shaped magnetic thin films are introduced. However, to date, capacitors are not used in order to store transported particles in these circuits. Here, TI magnetophoretic capacitors are introduced and characterized. The capability of the capacitor for storing particles of different sizes at various rotating magnetic field frequencies is studied. Towards this goal, finite element methods are used to simulate the magnetic potential energy distribution created by the magnetic thin films. Also, the trajectory of the magnetic particles, considering the drag forces, based on semi-analytical analysis and stochastic numerical analysis, are investigated. The simulation results are validated experimentally. At the operating frequency of 0.1 Hz loading efficiency of 98% was achieved. Adding this circuit element to the magnetophoretic circuits results in a complete chip, with important applications in lab-on-a-chip systems, single-cell biology, and drug screening.