2 research outputs found
Evaluation for diaphragm's deflection for touch mode MEMS pressure sensors
In this paper, an analytical and simulation solution for touch mode Micro-electromechanical systems pressure sensor operating in harsh environment is proposed. The principle of the paper is to design, obtain analytical solution and compare the results with the simulation using finite elements analysis for a circular diaphragm deflection before and after touch point. By looking at MEMS devices, when the diaphragm starts touching the fixed electrode by applying loads, it will have a major effect on the overall performance of the device. Therefore, one should consider the effect of touch mode in the system to achieve good linearity, large operating pressure range and large overload protection at output. As of so far the effect of touch mode has not been evaluated efficiently in the literatures. The proposed touch mode MEMS capacitive pressure sensor demonstrated diaphragm with radius of 180 μ m , the gap depth of 0.5 μ m and the sensor exhibit a linear response with pressure from 0.05 Mpa to 2 Mpa
Development of dynamic pressure sensor for high temperature applications
Pressure measurement under high temperature environments is required in many engineering applications and it poses many practical problems. Pressure patterns are highly desirable for health monitoring for improved performance and accurate prediction of remaining life of systems used in various applications. Data acquisition in harsh environments has always been a major challenge to the available technology. Sensing becomes more intricate in case if it has to operate under extreme conditions of temperature. Propulsion system applications represent one such area that requires a sensor that is absolutely accurate and has utmost sensitivity coupled with the ability to withstand high temperature. The need for such sensors is driven by the dependence of the performance of propulsion system on pressure pattern encountered along the gas path. Associated with that, high resolution, small size, low time dependent drift and stable range of measurement will complete the performance of such Microsystems Sensors using the current technology are capable of reliable measurement for a limited time at an extremely high cost and are bulky thereby preventing online monitoring. Improvement in the durability of the sensors requires new technology and will definitely open new areas of research. A number of technologies have been lately investigated, these technologies targeting specific applications and they are limited by the maximum operating temperature. The objective of this research is to develop a dynamic pressure measurement system that would be capable of operating at high temperatures with the technology of the device based on Silicon Carbon Nitride (SiCN). The principle of operation is based on the drag effect. Silicon carbon-nitride (SiCN) is a material that has been little explored. The service temperature of SiCN is in the range of 1400°C. The structure is produced from a liquid polymer precursor that could be originally formed into any shape. The proposed micro sensor can measure dynamic pressure and detects flow which is very important to know as the flow continuity is critical in many applications. Furthermore pressure measurement can be used as a base for many aspects. For example the proposed micro sensor could be designed and packaged to be fitted in the gas turbine engine. The correlation of the acquired data from the sensors may provide valuable timely information on imminent instability in the gas flow, detect leakage, improve efficiency et