A dielectrophoretic chaotic mixer

Abstract

The time needed for achieving mixing in a micro biochemical system takes the major portion of the whole processing time. The characteristic length scale is so small that the flows are laminar, leaving mixing dependent solely on diffusion. We present a dielectrophoretic mixer which induces chaotic trajectories of embedded particles via a combination in space and time of electrical actuation and local channel geometry variation. Mixing time is therefore dramatically reduced. The design is kept very simple and fabrication is done using standard microfabrication techniques. Experimental observations and numerical simulations show the conditions in which chaotic trajectories can be achieved.