Electrorotation of Arbitrarily Shaped Micro-Objects: Modeling and Experiments

In this article, we study the electrorotational behavior of nonspherical micro-objects. We extend a control-oriented model of general dielectrophoresis to incorporate also the hydrodynamics so that we can predict the motion of nonspherical micro-objects in fluidic environments. Such a mathematical (computational) model enables model-based feedback control of a position and orientation of particles by real-time (online) computation of voltages applied to the electrodes. We use the measured data from experiments with electrorotation of an artificial micro-object having a Tetris-like shape to evaluate the performance of the proposed model. We also demonstrate the qualitative difference in behavior from the commonly performed electrorotation of a sphere advocating the necessity for model-based control. Further analysis of the simulation results for other than the experimentally explored scenarios provides additional useful insight into the electrorotational behavior of nonspherical objects.