Overview of Research in Non-contact Manipulation Using Dielectrophoresis at CTU in Prague

The aim of this talk is to give an overview of the research conducted by our group over the last couple of years in the field of non-contact micromanipulation. In this research, we exploit the phenomenon of dielectrophoresis as a means of exerting a force on a microscale object by shaping an external electric field. The ultimate motivation for our research comes from the domain of bionanalytical instrumentation because this technology allows biological cells to be the manipulated objects. The focus of the talk will be on modeling, estimation, and control design. After introducing the very basic principle of dielectrophoresis including a description of a control-oriented mathematical model, the key idea behind the hierarchical control strategy will be explained - the higher-level positioning controller determines a required force that needs to be created at a given spot(s) and then the voltages that are to be applied to an array of microelectrodes are computed by solving a numerical optimization. The key computational challenge comes from the need to solve a nontrivial optimization in real time. Our description will be supported by data obtained using an experimental setup which uses our own simple yet clever layout of the microelectrodes enabling to perform a full three-dimensional manipulation of one or several microobjects. Another distinguished feature of our setup is that full 3D position of the manipulated object can be estimated in real-time using lensless visual sensing. Videos from experiments demonstrating a successful manipulation of one or several microobjects will also be presented.