Development of a Closed-loop MEMS Capacitive Force Sensor PDF Download

Author: Changhong Guan
Publisher:
ISBN:
Category :
Languages : en
Pages : 78

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Keywords: force-balanced, feedback, capacitive sensor, MEMS.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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This thesis describes a closed-loop microelectromechanical system (MEMS) based on lumped-parameter modeling. Analytical models are derived for electrostatic comb drive actuator (CDA) under force-controlled actuation, electrothermal actuator (ETA) under displacement-controlled actuation, capacitive position sensor, including parallel plate capacitive sensor (PPCS) and torsional plate capacitive sensor (TPCS), mechanical equation of motion of a suspended shuttle, viscous air damping, folded exure. These models are implemented and simulated in finite element analysis softwares (ANSYS and FEMM). System level simulation, implementing PID difierential feedback loop, is simulated in a numerical simulation program (MATLAB). The MEMS die is fabricated by following the standard PolyMUMPs process by MEMSCAP. A series of MEMS packaging process and storage are done in the lab. All peripheral circuitries are self-made. A commercial capacitive readout IC (MS3110) is first used for open-loop capacitive sensing, which achieves the resolution of 0.05fF, equivalent to 1nm in displacement. Due to the disadvantage of MS3110 in closed-loop, AC bridge capacitance measurement method is then implemented for closed-loop integration. The resolution of AC bridge sensor reaches 0.02fF, equivalent to 0.4nm in displacement. An additional function of AC bridge sensing is accomplished which is simultaneously sensing and actuation of CDA. In the feedback loop, the traditional analog PID controller is designed to transfer the voltage signal of capacitance measurement to the voltage-force transducer which converts feedback voltages to differential feedback force. Since the differential feedback force is limited by clamped voltage, a force-balanced mode is observed under 5V actuation of CDA.

Author: Craig Alan Baack
Publisher:
ISBN:
Category :
Languages : en
Pages : 298

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Author: Johan Schabbink
Publisher: LAP Lambert Academic Publishing
ISBN: 9783659107948
Category :
Languages : en
Pages : 80

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The starting concept is decomposed into system elements which have one function. For each system element a model is created that describes the behaviour of the element. Each system element model is than developed into a physical part of a MEMS system. During development the place on the structure and available space are closely monitored. Each part is designed for optimal resolution. The next step is to put all the physical MEMS parts together into a complete MEMS structure. With the MEMS structure defined, the last piece of the system can be designed. The controller is also the most essential part of the system because the MEMS structure itself is unstable during operation. The controller provides stability to the structure and is therefore very important. Bandwidth and stability are carefully balanced during the design of the controller.

Author: ALI OMAR NASSER. BANSS
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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This thesis presents the design and development of a capacitive MEMS force sensor to overcome the limitations associated with current force sensors used in touchscreens. The sensor uses two elastic materials that provide a dual-range of force sensitivity ensuring the sensor is able to sense light touch forces and able to withstand heavy ones. The fabrication process of the sensor was developed at the Toronto Nano Fabrication Centre at the University of Toronto. The fabricated sensor was experimentally tested to measure forces ranging from 50 mN to 5 N, with a force threshold of 625 mN that defines the boundary between the high sensitive region for light touches and the moderate sensitivity region. Sensor sensitivity was found to be 3.728pF/N (19.12 %∆C/N) in the first force region with maximum nonlinearity of 0.118 pF. In the second region, the sensitivity was 0.3194 pF (3.2 %∆C/N) with maximum nonlinearity of 0.3194 pF.

Author: Jaume Verd
Publisher: MDPI
ISBN: 3039210688
Category : Technology & Engineering
Languages : en
Pages : 166

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Micro and nano-electro-mechanical system (M/NEMS) devices constitute key technological building blocks to enable increased additional functionalities within Integrated Circuits (ICs) in the More-Than-Moore era, as described in the International Technology Roadmap for Semiconductors. The CMOS ICs and M/NEMS dies can be combined in the same package (SiP), or integrated within a single chip (SoC). In the SoC approach the M/NEMS devices are monolithically integrated together with CMOS circuitry allowing the development of compact and low-cost CMOS-M/NEMS devices for multiple applications (physical sensors, chemical sensors, biosensors, actuators, energy actuators, filters, mechanical relays, and others). On-chip CMOS electronics integration can overcome limitations related to the extremely low-level signals in sub-micrometer and nanometer scale electromechanical transducers enabling novel breakthrough applications. This Special Issue aims to gather high quality research contributions dealing with MEMS and NEMS devices monolithically integrated with CMOS, independently of the final application and fabrication approach adopted (MEMS-first, interleaved MEMS, MEMS-last or others).]

Author: Tan Tran Duc
Publisher: GRIN Verlag
ISBN: 3640249593
Category : Technology & Engineering
Languages : en
Pages : 83

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Diploma Thesis from the year 2005 in the subject Electrotechnology, grade: Master 9.8/10, , language: English, abstract: Microelectromechanical systems (MEMS) are collection of microsensors and actuators that have the ability to sense its environment and react to changes in that environment with the use of a microcircuit control. They also include the conventional microelectronics packaging, integrating antenna structures for command signals into microelectromechanical structures for desired sensing and actuating functions. The system may also need micropower supply, microrelay, and microsignal processing units. Microcomponents make the system faster, more reliable, cheaper, and capable of incorporating more complex functions. In the beginning of 1990s, MEMS appeared with the aid of the development of integrated circuit fabrication processes, in which sensors, actuators, and control functions are co-fabricated in silicon [1]. Since then, remarkable research progresses have been achieved in MEMS under the strong promotions from both government and industries. In addition to the commercialization of some less integrated MEMS devices, such as microaccelerometers, inkjet printer head, micromirrors for projection, etc., the concepts and feasibility of more complex MEMS devices have been proposed and demonstrated for the applications in such varied fields as microfluidics, aerospace, biomedical, chemical analysis, wireless communications, data storage, display, optics, etc. Some branches of MEMS, appearing as microoptoelectromechanical systems (MOEMS), micro total analysis systems, etc., have attracted a great research since their potential applications’ market.

Author: Yong Ping Xu
Publisher: CRC Press
ISBN: 1000793737
Category : Technology & Engineering
Languages : en
Pages : 312

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Book Description
Most MEMS accelerometers on the market today are capacitive accelerometers that are based on the displacement sensing mechanism. This book is intended to cover recent developments of MEMS silicon oscillating accelerometers (SOA), also referred to as MEMS resonant accelerometer. As contrast to the capacitive accelerometer, the MEMS SOA is based on the force sensing mechanism, where the input acceleration is converted to a frequency output. MEMS Silicon Oscillating Accelerometers and Readout Circuits consists of six chapters and covers both MEMS sensor and readout circuit, and provides an in-depth coverage on the design and modelling of the MEMS SOA with several recently reported prototypes. The book is not only useful to researchers and engineers who are familiar with the topic, but also appeals to those who have general interests in MEMS inertial sensors. The book includes extensive references that provide further information on this topic.

Author: Stephen Beeby
Publisher: Artech House
ISBN: 9781580538732
Category : Technology & Engineering
Languages : en
Pages : 282

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Book Description
Annotation Engineers and researchers can turn to this reference time and time again when they need to overcome challenges in design, simulation, fabrication, and application of MEMS (microelectromechanical systems) sensors.

Author: Mahmoud Rasras
Publisher: MDPI
ISBN: 3038974145
Category : Technology & Engineering
Languages : en
Pages : 252

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Book Description
Micro-electro-mechanical system (MEMS) devices are widely used for inertia, pressure, and ultrasound sensing applications. Research on integrated MEMS technology has undergone extensive development driven by the requirements of a compact footprint, low cost, and increased functionality. Accelerometers are among the most widely used sensors implemented in MEMS technology. MEMS accelerometers are showing a growing presence in almost all industries ranging from automotive to medical. A traditional MEMS accelerometer employs a proof mass suspended to springs, which displaces in response to an external acceleration. A single proof mass can be used for one- or multi-axis sensing. A variety of transduction mechanisms have been used to detect the displacement. They include capacitive, piezoelectric, thermal, tunneling, and optical mechanisms. Capacitive accelerometers are widely used due to their DC measurement interface, thermal stability, reliability, and low cost. However, they are sensitive to electromagnetic field interferences and have poor performance for high-end applications (e.g., precise attitude control for the satellite). Over the past three decades, steady progress has been made in the area of optical accelerometers for high-performance and high-sensitivity applications but several challenges are still to be tackled by researchers and engineers to fully realize opto-mechanical accelerometers, such as chip-scale integration, scaling, low bandwidth, etc. This Special Issue on "MEMS Accelerometers" seeks to highlight research papers, short communications, and review articles that focus on: Novel designs, fabrication platforms, characterization, optimization, and modeling of MEMS accelerometers. Alternative transduction techniques with special emphasis on opto-mechanical sensing. Novel applications employing MEMS accelerometers for consumer electronics, industries, medicine, entertainment, navigation, etc. Multi-physics design tools and methodologies, including MEMS-electronics co-design. Novel accelerometer technologies and 9DoF IMU integration. Multi-accelerometer platforms and their data fusion.