"Metal-oxide chemical sensor technology has been praised as a cheap and efficient method of detecting both reducing and oxidizing gases depending on the metal-oxide’s carrier type. The research conducted in this thesis explored methods of enhancing the sensitivity of an n-type metal-oxide material (indium tin oxide, ITO) to a volatile organic compound (VOC) through changes in both device and testing characteristics. Two methods of testing prototype sensors were developed which consisted of short and long-term exposure to ethanol at different temperatures and concentrations. Maximum sensitivity at 2000 ppm was achieved in devices with thin, annealed metal-oxide layers with a high temperature of operation; this sensitivity measurement was achieved using a prolonged exposure test with 100-nm of annealed ITO at an operating temperature of 360°C and yielded a sensitivity of 32.5%. A fabrication process consisting of two lift-off processes for the metal-oxide and contact metal was developed to create the prototype devices. Preliminary characterization on the metal-oxide materials confirmed its thickness, crystallinity / crystal structure, and grain size. In addition to the electrical tests, a future work chemical sensor was thermally and electrically simulated using SolidWorks and Silvaco Atlas, respectively; a proposed fabrication process of the device is also presented, along with a basic outline of future work experiments to further study sensitivity enhancements through other metal-oxide materials, noble catalytic metals, device architecture, and signal processing of proposed electrical testing."--Abstract.

This book focuses on the use of semiconducting metal oxides as gas sensing materials, including the sensing mechanism and sensing materials modification approach, 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 semiconducting metal oxides, one of the most important gas sensing materials, 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 investigate metal oxides nanomaterials synthesis and gas sensing with relevant frontier theories and concepts. Engineers working on research and development for semiconductor gas sensors will also find new ideas in sensor design.

Approx.530 pages Provides an overview of the material preparation and synthesis strategies of metal oxide composite and metal oxide hybrid materials for use in gas and humidity sensors Reviews emerging advanced metal oxide materials such as perovskites, spinel ferrites, and quaternary materials for gas and VOC sensors Discusses the potential opportunities and challenges to be circumvented in the use of metal oxide materials to enable new sensor technologies

Provides an introduction to the topic of smart chemical sensors, along with an overview of the state of the art based on potential applications This book presents a comprehensive overview of chemical sensors, ranging from the choice of material to sensor validation, modeling, simulation, and manufacturing. It discusses the process of data collection by intelligent techniques such as deep learning, multivariate analysis, and others. It also incorporates different types of smart chemical sensors and discusses each under a common set of sub-sections so that readers can fully understand the advantages and disadvantages of the relevant transducers—depending on the design, transduction mode, and final applications. Smart Sensors for Environmental and Medical Applications covers all major aspects of the field of smart chemical sensors, including working principle and related theory, sensor materials, classification of respective transducer type, relevant fabrication processes, methods for data analysis, and suitable applications. Chapters address field effect transistors technologies for biological and chemical sensors, mammalian cell–based electrochemical sensors for label-free monitoring of analytes, electronic tongues, chemical sensors based on metal oxides, metal oxide (MOX) gas sensor electronic interfaces, and more. Addressing the limitations and challenges in obtaining state-of-the-art smart biochemical sensors, this book: Balances the fundamentals of sensor design, fabrication, characterization, and analysis with advanced methods Categorizes sensors into sub-types and describes their working, focusing on prominent applications Describes instrumentation and IoT networking methods of chemical transducers that can be used for inexpensive, accurate detection in commercialized smart chemical sensors Covers monitoring of food spoilage using polydiacetylene- and liposome-based sensors; smart and intelligent E-nose for sensitive and selective chemical sensing applications; odor sensing system; and microwave chemical sensors Smart Sensors for Environmental and Medical Applications is an important book for senior-level undergraduate and graduate students learning about this high-performance technology and its many applications. It will also inform practitioners and researchers involved in the creation and use of smart sensors.

This book is a printed edition of the Special Issue "Volatile Organic Compounds in Environment" that was published in Environments

Semiconductor Gas Sensors, Second Edition, summarizes recent research on basic principles, new materials and emerging technologies in this essential field. Chapters cover the foundation of the underlying principles and sensing mechanisms of gas sensors, include expanded content on gas sensing characteristics, such as response, sensitivity and cross-sensitivity, present an overview of the nanomaterials utilized for gas sensing, and review the latest applications for semiconductor gas sensors, including environmental monitoring, indoor monitoring, medical applications, CMOS integration and chemical warfare agents. This second edition has been completely updated, thus ensuring it reflects current literature and the latest materials systems and applications. Includes an overview of key applications, with new chapters on indoor monitoring and medical applications Reviews developments in gas sensors and sensing methods, including an expanded section on gas sensor theory Discusses the use of nanomaterials in gas sensing, with new chapters on single-layer graphene sensors, graphene oxide sensors, printed sensors, and much more