Based on the software ANSYS

a coplanar capacitive sensor with 2-electrode structure is developed.A simulation study on effect of different combination of the gap

length and width of the electrode on capacitance change rate is carried out

and the best combination is obtained.A model of 8-electrodes of the coplanar capacitive sensor is established.The potential distribution and the sensitivity of the sensor is analyzed under the ground shield

gap shield and outer shield.Simulation result shows that increasing shielding can not only improve the sensitivity of sensor but also can get a uniform sensitive field.The result of the simulation provide basis for structure design of coplanar multi-electrode capacitive sensor.