Indexed on: 08 Sep '18Published on: 08 Sep '18Published in: Analytical Chemistry
Microfluidic systems have been developed widely in scaled-down processes of laboratory techniques, but they are usually limited in achieving stand-alone functionalities. It is highly desirable to exploit an integrated microfluidic device with multiple capabilities such as cells separation, single cell trapping, and cells manipulation. Herein, we reported a microfluidic platform integrated with actuation electrodes for separating cells and microbeads and bipolar electrodes for trapping, rotating, and propelling single cells and microbeads. The separation of cells and microbeads can be first achieved by deflective dielectrophoresis (DEP) barriers. Trapping experiments of yeast cells and polystyrene (PS) microbeads sus-pended in aqueous solutions with different conductivities were then conducted, showing that both of the cells and particles can be trapped at the center of wireless electrodes using negative DEP force. Upon application of a rotating electric field, yeast cells exhibit translational movement along the electrode edges and self-rotation at an array of bipolar electrodes by applying electrorotational torque and travelling wave DEP force on the cells respectively. The current approach allows to switch the propulsion and rotation direction of cells by varying the frequency of the applied electric field. Beyond the achievements of single-cell manipulation, this system permits effective control of several particles or cells simul-taneously. The integration of parallel sorting and single trapping stages within microfluidic chip enable the prospect of high-throughput cell separation, single trapping, large-scale cells locomotion and rotation in a non-invasive and disposable format, showing great potential in single cell analysis, targeted drug delivery and surgery.