Enhancing traveling-wave dielectrophoresis with signal superposition

In this article, a new method for cell separation and characterization and for monitoring cell physiological changes was described. In this approach termed superposition-TWD (travelling-wave dielectrophoresis), one or more DEP and TWD signals are applied together. The effect of such superposition of signals is to change the levitation height of the particles above the electrode plane, and in so doing to alter the range of frequencies over which TWD occurs. Appropriate choices of TWD signal strengths and frequencies, as well as the senses of the applied quadrature phase sequences, can result in cells of different type or physiological state traveling in opposite directions. This provides significant advantages over previously described TWD methods and can result in improved levels of attainable sensitivity and purity of cell separations on shorter electrode tracks.