Download or read book Gas Sensor Studies On Sensor Film Deposition ASIC Design And Testing written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The widespread use of Liquid Petroleum Gas (LPG) for cooking and as fuel for automobile vehicles requires fast and selective detection of LPG to precisely measure the leakage of gas for preventing the occurrence of accidental explosions. The adoption of Micro-Electro-Mechanical-System (MEMS) technology for fabricating the gas sensor provides other potential advantages for sensing applications, which includes low power consumption, low fabrication cost, high quality, small size and reliability. MEMS based gas sensor requires a sensitive layer of oxide material like ZnO, SnO2, TiO2, Fe2O3, etc. The tin oxide material used in the present work changes its electrical properties, as it interacts with the reducing gas like LPG. The sensor material becomes active only at high temperature such as 400ðC, thereby realizing the need of a micro heater to reach the desired temperature. To control the temperature of micro heater and to determine the change in electrical properties of the sensor due to its interaction with LPG an Application Specific Integrated Circuit (ASIC) forms an essential constituent of the MEMS based gas sensor. In the present work, an attempt has been made to improve the sensitivity of LPG gas sensor and it is correlated with other properties by different characterization techniques. The work also includes the design as well as testing of ASIC for gas sensor system. Process parameters particularly deposition time and substrate temperature have a profound influence on the microstructure of the tin oxide film, which in turn affects the gas sensing properties. To study the effects of these parameters, RF magnetron sputtering system is used for depositing tin oxide films onto the silicon substrate, which is compatible with CMOS technology. The effects of structural properties, optical properties and the porosity of the films are also studied and correlated with the gas sensing properties. In this direction the deposited films are characterized using X-Ray Diffr.
Download or read book Gas Sensors Micro Heater Designs And Studies On Sensor Film Deposition written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Current gas sensor technology, although meeting the minimum requirements in many instances, suffers for a number of limitations. Hence, there is currently a considerable volume of research being undertaken at many laboratories of different countries. In the past, all chemical sensors and catalyst were optimized empirically by a trial and error method. Today, however, systematic research and development is becoming increasingly important in order to improve sensors and to find new sensing principles. Obtaining a long term stable gas sensor with improved sensitivity, selectivity, and low cost for mass production passes through fundamental research and material characterization to build new chemically sensitive devices or to improve existing ones. The bottom line in the design and manufacture of modern gas sensors is the transfer from ceramic(of Figaro type) to thin film gas sensors(TFGs). This transfer provides new opportunities for further microminiaturization, power consumption and cost reduction of gas sensors. Therefore, at the present time, thin film gas sensors are the basis for the design of the modern gas sensitive multi-parameter microsensor systems. Applications of these systems include environment, security, home systems, smart buildings, transportation, discrete manufacturing, process industries and so on. Microelectromechanical systems(MEMS) based integrated gas sensors present several advantages for these applications such as ease of array fabrication, small size, and unique thermal manipulation capabilities. MEMS based gas sensors; which are usually produced using a standard CMOS(Complimentary Metal Oxide Semiconductor) process, have the additional advantages of being readily realized by commercial foundries and amenable to the inclusion of on-chip electronics. In order to speed up the design and optimization of such integrated sensors, microheater designs for gas sensor applications have been presented as first part of the present thesis. As heater des.
Download or read book Physics Chemistry and Technology of Solid State Gas Sensor Devices written by Andreas Mandelis and published by John Wiley & Sons. This book was released on 1993-10-06 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research and development of solid state gas sensor devices began in the 1950s with several uncoordinated independent efforts. The number and pace of these investigations later accelerated in response to increasing pressure placed on the environment and public health by industrial activities. Since 1970, several thousand articles have been written on the subject, and laboratories around the globe have introduced novel methodologies and devices to address needs associated with particular technological developments. Despite the rapid development of this important new technology, very little has been done to review and coordinate data related to sensor science and technology itself. Physics, Chemistry and Technology of Solid State Gas Sensor Devices focuses on the underlying principles of solid state sensor operation and reveals the rich fabric of interdisciplinary science that governs modern sensing devices. Beginning with some historical and scientific background, the text proceeds to a study of the interactions of gases with surfaces. Subsequent chapters present detailed information on the fabrication, performance, and application of a variety of sensors. Types of sensor devices discussed include: Gas-sensitive solid state semiconductor sensors Photonic and photoacoustic gas sensors Fiber optic sensors Piezoelectric quartz crystal microbalance sensors Surface acoustic wave sensors Pyroelectric and thermal sensors For analytical chemists using solid state sensors in environment-related analysis, and for electrical engineers working with solid state sensors, this book will expand and unify their understanding of these devices, both in theory and practice.
Download or read book Semiconducting Metal Oxides for Gas Sensing written by Yonghui Deng and published by Springer Nature. This book was released on 2023-08-23 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: The second edition of this book focuses on the synthesis, design, and application of semiconducting metal oxides as gas sensing materials, including the gas sensing mechanism, and modification methods for sensing materials, while also providing a comprehensive introduction to semiconductor gas sensing devices. As an essential part of IoT (Internet of things), gas sensors have shown great significance and promising prospects. Therefore, studies on functional mesoporous metal oxides, one of the most important gas sensing materials based on their unique Knudsen diffusion behavior and tailored pore structure, have increasingly attracted attention from various disciplines. The book offers a valuable reference guide to metal oxide gas sensing materials for undergraduate and graduate students alike. It will also benefit all researchers who are involved in synthesis and gas sensing of metal oxides nanomaterials with relevant frontier theories and concepts. Engineers working on research and development of semiconductor gas sensors will also find some new ideas for sensor design.
Download or read book Gas Sensors written by G. Sberveglieri and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 413 pages. Available in PDF, EPUB and Kindle. Book excerpt: There were two reasons that induced me to plan and to organize this book, the first was the lack of a text entirely devoted to the subject of gas sensors, notwithstanding some books devoted to the various kind of chemical sensors have recently been published. The second reason was the need of introducing the basic topics of gas detection mechanisms to a growing number of researchers active in research and development laboratories of industries and uni versities. The field of chemical sensors is indeed in fast and consistent growth, as it is proved by the increased number of participants to the congresses that were recently held on this subject, namely the Third Meeting on Chemical Sensors (September 24 - 26, 1990, Cleveland), Transducers' 91 (June 24 - 27, 1991, S. Francisco) and EUROSENSORS V (September 30 - October 3, 1991, Rome). Therefore, this book is mainly intended as a reference text for researchers with a MS degree in physics, chemistry and electrical engineering; it reports the last progresses in the R. & D. and in the technology of gas sensors. I choose to deal specifically with the topic of gas sensors because these devices show a very large number of applications in the domestic and industrial field and they are characterized by a great effort of research and development.
Download or read book Studies on Semiconductor Gas Sensors Using Nanostructure Growth Employing Ortho glancing Angle Deposition written by Dean R. Walters and published by . This book was released on 2019 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: A program of research was undertaken to develop the next generation of metal oxide gas sensors, which, for the purpose of this research, were made from materials using a unique approach of glancing angle deposition (GLAD) that is scalable to large scale production. This research seeks to demonstrate that high-sensitivity sensors can be produced. The sensors were examined in a test system of novel design in which the units underwent performance measurements using analyte gases, such as carbon dioxide, nitrogen, and water.Gas sensors can be improved by increasing the surface area of the active sensing media, and in this research the active surface is increased by forming the active material that is made of NiO into 1D nanopillars. A unique technique, which integrates magnetron sputtering with a variant of GLAD to deposit an array of NiO nanopillars, is described. The deposition angle is increased to 90° (i.e., the magnetron gun axis is parallel to the target surface), and reactive sputtering is used to make NiO nanostructures. The nanopillars made by fully orthogonal glancing angle deposition ("ortho-GLAD") are produced by NiO adatom scattering above the surface sample. In the study, different materials (i.e., Al, Nichrome A, Sn, and NiO) were tested to see if nanopillars could be made. Other investigators believe that there is a relationship between the length of the pillar and its width, so by using a plasma on the sample, the researcher investigated whether the width can be modified independently of the length by changing the adatom surface mobility. The coatings were analyzed using SEM, EDS, and XRD and show the composition and morphology of the materials.The research also describes the performance of an NiO gas sensor that was composed of an array of nanopillars. These nanopillars were made using a combination of GLAD and reactive sputtering. The material was analyzed using a number of characterization techniques, which identified it to be nearly stoichiometric NiO. Measurements of the nanopillars show them to be 50 nm across with lengths of 400 nm. Sensors were made using this process and were tested using carbon dioxide, ethanol, nitrogen, and water vapor. The threshold of sensing for CO2 is 1.6 x 10−3 torr at 305 °C, 6 x 10−4 torr at 310 °C for ethanol, and 6 x 10−4 torr at 330 °C for water vapor.
Download or read book Asic Gas Sensors Based on Ratiometric Principles written by and published by . This book was released on 2009 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Application of Sculptured Thin Film Technology to Metal Oxide Gas Sensors written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The main goal of this research has been the application of glancing angle deposition (GLAD) techniques to create highly porous sculptured thin films (STF) structures for use as gas sensors. The glancing angle technique utilizes physical vapor depositions at highly oblique (>70 & deg;) angles of incidence to form porous film structures. Process conditions including the deposition rate, rotation speed, and flux angle were investigated to produce pillar and chevron formations. Control of the anatase/rutile percentages in TiO2 gas sensors is critical for design and development. Thin films were deposited using reactive e-beam evaporation with a titanium source melt at various partial pressures of oxygen and argon. Post deposition anneal studies were conducted in air from 150-900 & deg;C. The combination of reactive evaporation at high oxygen partial pressures and low temperature (150 & deg;C) anneals in air formed films with the highest percentage of anatase. Depositions at lower oxygen partial pressures yielded films with a higher percentage of rutile, which supports the role of oxygen vacancies as nucleation centers for the anatase to rutile transformation. Higher temperature annealing produced rutile films as expected from the thermodynamics of the TiO2 system. After the formation of anatase STF structures, the films displayed a high degree of temperature stability with subsequent annealing. Anatase films structures were still evident even after annealing at 1200 & deg;C in air. The GLAD technique produces films with preferred crystal orientations which differ based on the deposition angle. A series of experiments looked at the effect of the angle of incidence, the deposition conditions, and the substrate material on the crystal structure of the STF structures. The titanium films did show a dependence of the crystalline structure on the angle of incidence for both as-deposited films and after oxidation at 900 & deg;C in air. A conductive MOS sensor was designed based on.
Download or read book Development Of A Tin Oxide Based Thermoelectric Gas Sensor For Volatile Organic Compounds written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Today there is a great deal of interest in the development of gas sensors for applications like air pollution monitoring, indoor environment control, detection of harmful gases in mines etc. Based on different sensing principles, a large variety of sensors such as semiconductor gas sensors, thermoelectric gas sensors, optical sensors and thermal conductivity sensors have been developed. The present thesis reports a detailed account of a novel method followed for the design and development of a thermoelectric gas sensor for sensing of Volatile Organic Compounds. Thermoelectric effect is one of the highly reliable and important working principles that is widely being put into practical applications. The thermoelectric property of semiconducting tin oxide film has been utilized in the sensor that has been developed. The thermoelectric property of semiconducting tin oxide film has been utilized in the sensor. The deposition parameters for sputtering of tin oxide film have been optimized to obtain a high seebeck coefficient. A test set-up to characterize the deposited films for their thermoelectric property has been designed and developed. A novel method of increasing the seebeck coefficient of tin oxide films has been successfully implemented. Thin films of chromium, copper and silver were used for this purpose. Deposition of the semiconducting oxide on strips of metal films has led to a noticeable increase in the seebeck coefficient of the oxide film without significantly affecting its thermal conductivity. The next part of our work involved development of a gas sensor using this thermoelectric film. These sensors were further tested for their response to volatile organic compounds. The sensor showed significant sensitivity to the test gases at relatively low temperatures. In addition to this, the developed sensor is also selective to acetone gas.
Download or read book Science Abstracts written by and published by . This book was released on 1995 with total page 1360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 682 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Automotive Engineering written by and published by . This book was released on 1995 with total page 1038 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2540 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1997 with total page 1948 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Index to IEEE Publications written by Institute of Electrical and Electronics Engineers and published by . This book was released on 1997 with total page 1468 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polymer Films in Sensor Applications written by Gabor Harsanyi and published by Routledge. This book was released on 2017-10-19 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymer films now play an essential and growing role in sensors. Recent advances in polymer science and film preparation have made polymer films useful, practical and economical in a wide range of sensor designs and applications. Further, the continuing miniaturization of microelectronics favors the use of polymer thin films in sensors. This new book is the first comprehensive presentation of this technology. It covers both scientific fundamentals and practical engineering aspects. Included is an extensive survey of all types of sensors and applications. The very detailed table of contents in the next pages provides full information on content. More than 200 schematics illustrate a wide variety of sensor structures and their function.
