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Dielectrophoresis is a phenomenon with wide application in the cell sorting system, in which, the dielectrophoresis force acts on a dielectric particle located in the non-uniform electric filed is used. In this study, governing equations on this phenomenon is presented and a new method for measuring dielectrophoresis force is developed. This method is based on measuring drag force on particle and solving the equilibrium equations. For this purpose drag force is measured in two directions, parallel and perpendicular to electrodes. To evaluate the method, an actuator has been developed which has paralleled electrodes with 50 μm widths and 50 μm intervals and a PDMS channel with height of 80 μm is mounted on them. In experimental result, the exerted dielectrophoretic force on U-87 tumor cell and white blood cell were measured. Since electrical properties of white blood cells are known, the accuracy of presented method was evaluated by using numerical simulation of their dielectrophoretic force and comparing with experimental results. Experimental results prove that the error of force measurement in traditional models, may be even more than 3 time of the actual dielectrophoresis force, while in presented method the source of this error is eliminated

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In surface acoustic wave sensors, target cells are trapped by sacrificial layer, containing antigens and antibodies. In this new idea, sacrificial layer is replaced by diectrophoresis electrodes. Fast response and not being disposable and usability for various types of cells are its advantages. In order to design and fabricate the sensor, the optimized values of effective parameters have been investigated. The behavior Love wave - which is used in this sensor - is simulated with lithium Niobate as substrate and ZnO layer as guiding layer. Two types of focus and unfocus interdigital transducer electrodes for sensor are investigated. The results of the sensitivity analysis and its relationship with the sensor displacement are presented. In graphs, results indicate that the focused circular structure is more sensitive, when the number of target cells in the fluid channel is more. The sensor was tested in 142 MHz for healthy and cancerous brain and intestinal cells. The suggested sensor has good results for measurement of cells aggregation. Wave power loss in transmission from sender to receiver ports and frequency shift are two special properties for detecting healthy and cancerous cells. Results show 80 and 90 KHz decrease in frequency and 4.99 and 6.69 dB loss decrease in cancerous cells comparing to healthy cells in brain and intestinal cells respectively. In this sensor, trapping, detecting and measurement of aggregation, happens in 5-10 second, which is an outstanding result compare to 10 – 15 minutes in conventional methods.