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A Mems Planar Fresnel Lens For Cmut Array, Shivani Nilesh Upadhyay
A Mems Planar Fresnel Lens For Cmut Array, Shivani Nilesh Upadhyay
Electronic Theses and Dissertations
This thesis presents a Microelectromechanical Systems (MEMS) planar Fresnel lens for use with a Capacitive Micromachined Ultrasonic Transducer (CMUT) array for high-resolution cardiac diagnostic imaging applications. The research exploited the excellent sound propagation and thermal properties of cross-linked silica aerogel, a nano-porous, nano-networked ultra-light-weight material, to design a planar thinfilm lens that can be easily microfabricated or integrated with a CMUT array. The designed lens, comprised of 32 various width concentric rings, was optimized to operate with a 256 element 6 MHz CMUT array. The 4 µm thick lens was designed to generate a 1.9 mm focal spot at a …
Design Of A Regulated Micromachined Air-Sniffer Using Thermal Transpiration Effect For E-Nose Applications, Mukesh Arvind Raju
Design Of A Regulated Micromachined Air-Sniffer Using Thermal Transpiration Effect For E-Nose Applications, Mukesh Arvind Raju
Electronic Theses and Dissertations
Microfluidics artificial olfaction systems are used for plant disease diagnosis in the agricultural field. In an electronic nose, the sniffer draws the air towards an array of gas sensors that detect volatile organic compounds corresponding to diseased plants. The currently available electronic noses involve a mechanical pump of moving parts prone to friction losses, limiting large-scale application. In this work, a microchannel that works on thermal transpiration principle to control the airflow inside it is proposed and designed. It has the potential to be employed as a sniffer component for electronic noses, designed using microelectromechanical systems. COMSOL Multiphysics simulation software …
Design And Modeling Of Piezoelectric Micromachined Ultrasonic Transducer (Pmut) Using A Multi-User Mems Process For Medical Imaging, Jenitha Antony Balasingam
Design And Modeling Of Piezoelectric Micromachined Ultrasonic Transducer (Pmut) Using A Multi-User Mems Process For Medical Imaging, Jenitha Antony Balasingam
Electronic Theses and Dissertations
According to the Canadian Cancer Society, 2020, “1 in 8 women will be affected by breast cancer and 1 in 33 will die from it.” There has been a decline in breast cancer causalities due to the early detection using advanced imaging technologies. This signifies the importance of early detection of breast cancer that increases the survival rate and treatment options for the patients. One of the platforms which are aiding the early detection is Microelectromechanical Systems (MEMS)-base imaging system. In this thesis, a Piezoelectric Micromachined Ultrasonic Transducer (PMUT) is proposed to work at lower frequency ranges for higher penetration …
Developing Highly Symmetric Microelectromechanical Systems (Mems) Based Butterfly Gyroscopes, Nabeel Ahmad Khan
Developing Highly Symmetric Microelectromechanical Systems (Mems) Based Butterfly Gyroscopes, Nabeel Ahmad Khan
Electronic Theses and Dissertations
Microelectromechanical systems (MEMS) is the technology combining electrical components with mechanical systems at a micro scale. The combination of these two technologies allowed devices to interact with each other and build complex structures. System on the chips are built with components such as masses, electrodes, anchors, actuators and detectors. Reducing the size, weight, energy usage and cost is key while maintaining the sensors integrity. Sensitivity is an important factor when evaluating a gyroscope’s performance. This research presents beam modeling techniques for maximizing mechanical sensitivity of the butterfly resonator for gyroscopic applications. It investigates the geometric aspects of synchronizing beam that …
A Miniaturized Chemical Vapor Detector Using Mems Flexible Platform, Haleh Nazemi
A Miniaturized Chemical Vapor Detector Using Mems Flexible Platform, Haleh Nazemi
Electronic Theses and Dissertations
According to the Canadian Cancer Society, lung cancer is the one of the leading causes of cancer death. It has been shown that cancer survival chance depends on factors including the availability of early detection and diagnostic tools such as miniaturized and sensitive gas sensor. This can detect the released volatiles in addition to be implementable in portable electronics, which decisively improves the patient’s survival rate. Therefore, in this thesis and in an effort to develop high-sensitive and miniaturized gas sensor, a microelectromechanical systems (MEMS) platform is utilized. In this work, a sensitive gas sensor is proposed by employing capacitive …
Energy Harvesting For Iot Sensors, Parvathi Shenoy Kasargod
Energy Harvesting For Iot Sensors, Parvathi Shenoy Kasargod
Electronic Theses and Dissertations
The growing need for alternative energy sources for sensors and portable devices has led to many energy-harvesting solutions. As the technology scales down and the supply voltage drops, the complexity of designing energy harvesting circuits increases. In this work, a vibrational energy harvester using Microelectromechanical systems (MEMS) based switches is proposed. The MEMS switches are used to design a high efficiency rectifier instead of diodes. The voltage drop across diodes in conventional rectifiers reduces the efficiency of energy harvesters. The operation of the MEMS switches in the proposed rectifier is similar to the commutators in DC motor where alternating current …
A Resonant Based Test Methodology For Capacitive Mems, Ali Dianat
A Resonant Based Test Methodology For Capacitive Mems, Ali Dianat
Electronic Theses and Dissertations
This work presents a test method for capacitive Micro-Electro-Mechanical Systems (MEMS). A major class of MEMS sensors operate based on the principle of capacitance variation.The proposed test method in this work utilizes a resonant circuit to detect structural defects of capacitive MEMS sensors. It is shown that a small variation of MEMS capacitance due to a defect alters the resonance frequency considerably. It is also shown that the variation of the output amplitude can be observed for fault detection if an inductor with a high quality factor is employed in the test circuit. Mathematical approach is taken and verified to …
A 5 Meter Range Non-Planar Cmut Array For Automotive Collision Avoidance, Jonathan Hernandez Aguirre
A 5 Meter Range Non-Planar Cmut Array For Automotive Collision Avoidance, Jonathan Hernandez Aguirre
Electronic Theses and Dissertations
A discretized hyperbolic paraboloid geometry capacitive micromachined ultrasonic transducer (CMUT) array has been designed and fabricated for automotive collision avoidance. The array is designed to operate at 40 kHz, beamwidth of 40° with a maximum sidelobe intensity of -10dB. An SOI based fabrication technology has been used for the 5x5 array with 5 sensing surfaces along each x and y axis and 7 elevation levels. An assembly and packaging technique has been developed to realize the non-planar geometry in a PGA-68 package. A highly accurate mathematical method has been presented for analytical characterization of capacitive micromachined ultrasonic transducers (CMUTs) built …
Bio-Mechanically Driven Mems Power Generator For Implantable Medical Devices., Jose Martinez-Quijada
Bio-Mechanically Driven Mems Power Generator For Implantable Medical Devices., Jose Martinez-Quijada
Electronic Theses and Dissertations
No abstract provided.
A Mems Non-Planar Ultrasonic Microarray., Matthew Meloche
A Mems Non-Planar Ultrasonic Microarray., Matthew Meloche
Electronic Theses and Dissertations
No abstract provided.
A Mems Sonoluminescent Ultrasonic Sensor., Andrew Tam
A Mems Sonoluminescent Ultrasonic Sensor., Andrew Tam
Electronic Theses and Dissertations
No abstract provided.