Abstarct: Today, the manipulation of biological particles is very important in various medical and biotechnology applications. Recently, a lot of research has been done in the design of nano and micro systems to manipulate biological particles using electrokinetic forces. Dielectrophoresis force is a useful tool to manipulate particles in microfluidic systems. This force depends on the frequency and the square gradient of the electric field as well as the dielectric properties of the fluid and particles. By adjusting these factors, an efficient system for manipulating particles can be designed. In this research, firstly, a two-dimensional microchannel including a chamber is introduced, in which the phenomenon of separation and trapping of dielectric particles is numerically investigated using the dielectrophoresis force. The purpose of introducing this microchannel is to separate particles and trap a group of them in the microchannel chamber. This microchannel contains several different electrodes. In the initial part of the microchannel, two electrodes placed on the cilling and bottom of the microchannel have the task of focusing and reducing the dispersion of incoming particles. These electrodes are known as focusing electrodes. Next, there are repulsive electrodes on the walls of the chamber, which have the role of removing particles from the walls and preventing them from sticking to the walls of the chamber. The frequency of the focusing and attractive electrodes is such that they produce a negative dielectrophoresis force and repel the particles towards the weaker field. After the particles pass through the first wall of the microchannel chamber, the particles encounter the attractive electrodes and are trapped inside the chamber by these electrodes. The frequency of these electrodes is different from other electrodes and they create a positive dielectrophoresis force. This force pulls the particles towards the stronger electric field. Of course, it is important to mention that at this stage only the target particles are trapped inside the chamber and the rest of the particles are directed out of the microchannel. In the next step, the second microchannel, which includes two chambers, is introduced. The purpose of introducing this microchannel is to separate particles and trap them inside the microchannel chambers. This microchannel, like the first microchannel, also includes focusing, repulsive and attractive electrodes, except that it has an additional chamber. This microchannel is able to absorb different particles inside its chambers. In the next section, to further validate the numerical results, a three-dimensional microchannel including a chamber for trapping particles is introduced. 3D modeling using this microchannel leads to more realistic results. This microchannel includes two groups of focusing and attractive electrodes. In the end, to validate the numerical results, a microfluidic system according to the 3D microchannel is built and particle trapping is investigated in it. In this experiment, yeast particles are injected into the microchannel along with the working fluid by a syringe pump. By applying voltage to the electrodes inside the microchannel, the yeast particles are trapped inside the microchannel chamber. The test results show the correct performance of the proposed system.