(415g) Microparticle Manipulation Employing Low Frequency AC Electric Fields with Insulator-Based Dielectrophoresis

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 potential 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 trapped 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 1 Hz range. Three different signals were tested: sinusoidal, half sinusoidal and sawtooth. Experimental results demonstrated that this novel dielectrophoretic mode allowed highly modulated dielectrophoretic particle manipulation. The development of low frequency AC-iDEP as a technique to manipulate bioparticles has great potential for many biotechnological applications. This novel dielectrophoretic mode allows for an extra parameter to modulate dielectrophoretic mobilization of particles and/or groups of particles; since bands of immobilized particles can be manipulated by varying the shape of the applied AC potential. This highly controlled process could be used to improve the separation and fractionation of mixtures of particles, which are common challenges in many biotechnological applications.