**4. Conclusions**

In this study, a DSMC technique is used to investigate rarefied gas inside the lowpressure micro gas sensor. This research has dedicated on the impact of pressure in the flow structure and force generation mechanism. In order to simulate the defined model, Boltzmann equations as governing equations of the present problem are introduced and DSMC method as accessible and robust approach is then offered. The two main key factors are flow patterns and temperature distribution. In this work, these main parameters are compared in various pressures with different temperature of hot and cold arm. Moreover, inclusive physical details on the appliance of Knudsen force production as well as flow structure inside the micro gas actuator are offered. Our findings display that the performance of micro gas sensor highly relies on the temperature difference between hot and cold arms, and the maximum force occurs in specific pressure value for all different temperature difference. On the other side, the effect of gap size is considerable different. Obtained results show that the maximum force occurs in lower pressure as the size of gap is increased. It is also observed that the value of Knudsen force significantly declines when the gap size rises. According to our findings, application of the Knudsen force for the measurement of the gas pressure is a reliable technique and this micro gas actuator could be develop for possible detection of the gas component.
