Modeling and simulation of a novel pressure sensor based on the principle of thermal transpiration

Abstract

In this paper we advance novel mechanisms for enhanced functioning of Knudsen micro-cantilevers. Using rarefied gas molecular simulation technique, DSMC, we herein demonstrate the validity of various earlier proposals, made by researchers for the possibility of construction of such devices, for the first time. Further we investigate the onset of thermal transpiration forces, also known as Knudsen forces on the cantilevers, for different pressure and temperature ranges. Our investigation shows that Knudsen cantilevers can be conveniently utilized for the design of sensors for such macroscopic properties as temperature, infrared radiation, etc when the surrounding pressure can be reduced sufficiently, and also for the measurement of ultra-high vacuum pressures, after some initial calibration. Till date measurements of ultra low pressures, have been made using devices such as pirani gauges, cold cathode/hot cathode ionization gauges etc. However due to many technical complexities, their cost of production, maintenance and usage is very high. On the other hand, this present device presents a novel architecture for use in ultra high vacuum ranges, without inculcating the additional complexities of using the ionization gauges.