Polymer microcantilever arrays for high-throughput separation using a combination of dielectrophoresis and sedimentations

This paper presents a polymer microcantilever platform for handling massive microparticles or cells using combined forces induced by dielectrophoresis and gravity. Although cell separation based on dielectrophoresis is a very useful and versatile method, its low throughput is a key problem that must be resolved before it can be used clinically. In this study, high throughput separation could be achieved without any external pumping or complex microtubing by combining dielelectrophoresis and sedimentation. The absence of any external pumping or injection system makes it possible to realize a simple configuration of devices with low cost and easy separation procedures, which is carried out by just dropping the target microparticles without any pretreatment. The transport of microparticles is driven by gravitation in the medium, and during the sedimentation the particles are either deflected from or pass through the gap between the microcantilevers depending on their physical properties. The position of passing through is defined by the equilibrium point between the dielectrophoretic force and gravity. We compared the degree of complexity of the fabrication process and its successful throughput between both the glass-based and polymerbased microcantilevers. The feasibility of our suggestion was demonstrated by performing microparticle separation experimentally, which showed that our device can be applied in various biological areas.