Controlled microparticle manipulation employing low frequency alternating electric fields in an array of insulatorsElectronic supplementary information (ESI) available: Video S1-S4. See DOI: 10.1039/c0lc00097c

Low frequency alternating current insulator-based dielectrophoresis is a novel technique that allows for highly controlled manipulation of particles. By varying the shape of an AC voltage applied across a microchannel containing an array of insulating cylindrical structures it was possible to concentrate and immobilize microparticles in bands; and then, move the bands of particles to a different location. Mathematical modeling was performed to analyze the distribution of the electric field and electric field gradient as function of the shape of the AC applied potential, employing frequencies in the 0.2-1.25 Hz range. Three different signals were tested: sinusoidal, half sinusoidal and sawtooth. Experimental results demonstrated that this novel dielectrophoretic mode allows highly controlled particle manipulation. Dielectrophoretic manipulation of bands of particles employing a sawtooth AC voltage with low frequencies allow entire bands of particles to ''jump'' from one column to the next within an array of cylindrical insulating structures.