Unraveling the nature of sensing in electrostatic MEMS gas sensors

作     者：Yasser S.Shama Sasan Rahmanian Hamza Mouharrar Rana Abdelrahman Alaaeldin Elhady Eihab M.Abdel-Rahman 

作者机构：Systems Design EngineeringUniversity of Waterloo200 University Ave WWaterloo N2L 3G1 ONCanada Mechanical EngineeringBenha Faculty of EngineeringBenha UniversityBenha 13511Egypt 

出 版 物：《Microsystems & Nanoengineering》 (微系统与纳米工程（英文）)

年 卷 期：2024年第10卷第3期

页      面：109-117页

核心收录：

学科分类：080202[工学-机械电子工程] 08[工学] 0802[工学-机械工程] 

基　　金：CMC Microsystems, CMC University of Waterloo, UW 

主　　题：mechanism electrostatic measurable 

摘      要：This paper investigates the fundamental sensing mechanism of electrostatic MEMS gas *** compares among the responsivities of a set of MEMS isopropanol sensors before and after functionalization,and in the presence and absence of electrostatic fields when operated in static and dynamic detection *** the static mode,we found that the sensors do not exhibit a measurable change in displacement due to added *** the other hand,bare sensors showed a clear change in displacement in response to isopropanol *** the dynamic mode,functionalized sensors showed a measurable frequency shift due to the added mass of isopropanol *** the presence of strong electrostatic fields,the measured frequency shift was found to be threefold larger than that in their absence in response to the same concentration of isopropanol *** enhanced responsivity of dynamic detection allows the sensors to measure the vapor mass captured by the functional material,which is not the case for static *** detection of isopropanol by bare sensors in static mode shows that change in the medium permittivity is the primary sensing *** enhanced responsivity of dynamic mode sensors when operated in strong electrostatic fields shows that their sensing mechanism is a combination of a weaker added mass effect and a stronger permittivity *** findings show that electrostatic MEMS gas sensors are independent of the direction of the gravitational field and are,thus,robust to changes in *** is erroneous to refer to them as‘gravimetric’sensors.