Capacitive mems sensor, capacitive micromachined ultrasonic transducer cmut, pressure sensor, comsol multiphysics. Performance optimization of a capacitive pressure sensor. Operation of capacitive sensor is quite stable and the output of measurement is highly linear. They are compressed against each other in response to a change in pressure, which causes the capacitance to change. There is no need to activate a manual terminal sweep and define a portname variable and a parametric sweep. The present work demonstrates the design of mems based capacitive pressure sensor using comsol multiphysics. In this paper, the thermomechanical modelling of an entire sensor structure, under hydrostatic pressure, is carried out using commercial fem software comsol multiphysics. The mems capacitive pressure sensor was designed and simulated using comsol multiphysics software ver. If you are searching for a tutorial on how to model a miniaturized 3d electromechanics problem, then look no further. The model consists of graphene, steel aisi 4340 and air.
Capacitive pressure sensor a capacitive pressure sensor is simulated. Modeling electromechanics in a capacitive pressure sensor. Design analysis of mems capacitive differential pressure. For example, if youre going to create a new product or process, such as a capacitive pressure sensor, youll.
Introduction capacitive mems devices offer several advantages due to their size, cost and ease of. Department of electronics and communication engineering, periyar maniammai university, vallam, thanjavur 64. Pressurea diaphragm with stable deflection properties can measure pressure. Mems, pressuresensor, comsol multiphysics, sensitivity. Thermal study in this section the sensor thermal behavior study at rest p 0 has been performed.
The capacitive pressure sensor has some advantages over the piezoresistive and piezoelectric pressure senor. These micro pressure sensors can also resolve all relevant scales even in high reynolds number turbulent flows and arrays of micro pressure sensors make it feasible. For this, we adopt the model of finite element analysis in comsol. Modeling and simulation of capacitive pressure sensor. Highly sensitive mems based capacitive pressure sensor design. The fluidstructure interaction fsi multiphysics interface combines fluid flow with solid. Introduction continuous monitoring of modern devices are critically needed using mems microelectro mechanical systems. Tutorial on modeling a capacitive position sensor using fem. Capacitive pressure sensors provide high sensitivity to pressure, low power consumption, low noise, large dynamic range and low thermal sensitivity than piezoresistive pressure sensors 2. This tutorial model explains how to extract lumped matrices by means of the stationary source sweep study. It provides the user with the flexibility to model the sensor using a simple 2d user interface that can be easily transformed into a. Simulation of mems based capacitive pressure sensor using. Conclusion it is observed that the output voltage values obtained from analytical equations are matching with the simulated results.
In this comsol model a capacitive pressure sensor is built where there is an upper and lower membranes, as the. Modelling of different mems pressure sensors using. The capacitance matrix of a fiveterminal system is used to infer the position of a. The sensor model is simulated by comsol multiphysics software. Compared to capacitive pressure sensors, they are simpler to integrate with electronics, their response is more linear and they are inherently shielded from rf noise. We have just published an updated version of our video tutorial on how to simulate a capacitive pressure sensor. Characteristics of square diaphragm piezoresistive pressure sensor comsol multiphysics. Learn stepbystep how to set up and solve a capacitive pressure sensor model in comsol multiphysics. The mechanical and electrical effects of mems capacitive. Furthermore, this example may also be defined and modeled using components. Capacitive sensors can be virtually designed using a powerful 3d modeling software, comsol. Modelling of different mems pressure sensors using comsol. Capacitive transducers are simple, durable and fundamentally stable.
By increasing the diaphragm size, reducing the diaphragm thickness and decreasing sensing gap we can achieve high sensitivity of. One of the most important sensors in nanotechnology, mems design or control systems are the capacitive pressure sensors. This application note will instruct the user on how to design a capacitive sensor using a 3d modeling software called comsol. In this example, we examine the performance of the pressure sensor. Furthermore, the design of high performance conventional siliconbased pressure sensors for low.
These sensors work by sensing a conductive object nearby rather than detecting the physical state of the device. Microelectromechanical systems mems capacitive pressure sensors. Capacitive pressure sensors are making themselves the. Silicon micromachined capacitive pressure sensors for. In contrast to other homebrew dance pads, it uses capacitive sensing, eliminating mechanical wear and allowing adjustable sensitivity. The new capacitive position sensor tutorial model uses the stationary source sweep study step. Mems sensor measure the pressure in term of deflection of sensing plate.
Modeling and simulation of dual application capacitive. Modeling and simulation of high sensitivity cmos pressure. All the parameters are keywords mems, comsol multiphysics, capacitive needed to be optimized to obtain the desired specification of pressure sensor. Simulation analysis of capacitive pressure sensor for mems using graphene. Mems based pressure sensor using comsol multiphysics. Capacitive sensors can then measure the displacement. A capacitive pressure sensor is achieved by engineering a circuit such. A comparison of the obtained results with those found in the literature, allows us to corroborate the wellknown models. Keywords capacitive pressure sensor, comsol multiphysics, diaphragm displacement, packaging stress, sensitivity thi i.
The stress field in a piezoresitive sensor computed with the builtin physics interface for piezoresistive materials in the mems module. Simulation based analysis of capacitive pressure sensor. Thermal drift characteristics of capacitive pressure sensors 351 journal of engineering science and technology march 2016, vol. However, capacitive pressure sensor is very sensitive to high temperature. Capacitive proximity sensors theory of operation capacitive proximity sensors are similar to inductive proximity. The paper describes the design considerations and comsol simulation results. Mems based capacitive pressure sensor simulation for. Simulation based analysis of capacitive pressure sensor with comsol multiphysics article in international journal of engineering and technical research v404 april 2015 with 63 reads. Publication capacitive pressure sensors based on mems, operating in harsh environments. Abstractthis paper presents the design and characterization of a simulation of a capacitive blood pressure for healthcare and biomedical applications. A capacitive based mems humidity sensor is designed and tested using. Some are flowmany types of flow meters convert flow to pressure or displacement, using an orifice for volume flow or coriolis effect force for mass flow. Capacitive sensors provide an alternative to the traditional mechanical buttons and sliders in electronics. The basic geometry of the model is imported from built in comsol file.
The sensing surface of a capacitive sensor is formed by two concentrically shaped metal electrodes of an unwound. Design of sensor the capacitive humidity sensor mainly consists of two metal armatures between which an insulating polymer is sandwiched layer acts as a dielectric. Pdf simulation analysis of capacitive pressure sensor. Variable capacitor technology, a rugged physical configuration, stainless steel wetted parts and a careful marriage of the mechanical assembly to the electronic circuitry combine to create highly repeatable transducers with low hysteresis and only 0. Try it yourself with this tutorial model of a capacitive position sensor. Introduction there are many excellent reasons to simulate microelectromechanical system mems devices. The fabricated pressure sensors are based on the deflecting micromachined thin silicon diaphragm anchored to glass substrate, forming variable capacitor with the applied pressure. Capacitive differential pressure sensor measures changes in pressure by the deflection of a conductive diaphragm due to the applied pressure.
In a capacitive pressure sensor, two membranes are mounted in parallel, one of which is in contact with the fluid under pressure figure 1b. Stress developed due to applied pressure changes the drain current and hence the output voltage produced. In this paper we have designed and simulated the micro pressure sensor using mems tool comsol multiphysics. Design and simulation of mems based micro pressure sensor. The analytical study of model 4 is not included in the scope of this work. Operation normally a capacitive pressure sensor has a diaphragm for sensing the pressure. Mems based capacitive pressure sensor simulation for healthcare and biomedical applications. Coventorware tutorial university of california, berkeley. The aim of this project is the design and fabrication of two type of micromachined capacitive pressure sensor for industrial and biomedical application.
Gas pressure capacitive sensor on comsol matlabworks. This model shows how to simulate the response of the pressure sensor to an applied pressure, and also how to analyze the effects of packing induced stresses on the sensor performance. The simulation model of capacitive pressure sensor is implemented by comsol multiphysics 4. Piezoresistive pressure sensors were some of the first mems devices to be commercialized. Piezoresistive pressure sensor, shell comsol multiphysics. A stationary source sweep is also easier to set up. Mems based pressure sensor using comsol multiphysics p. The most important decisions are often made early in.
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