Capacitive Sensors

Capacitive sensors produce spectacular resolution of movement to one part in 10-10 meters and maintain exceptional long-term stability in hostile environments. They are increasingly used for a variety of jobs in consumer and industrial equipment, including wall stud sensors, keypads, lamp dimmers, micrometers, calipers, rotation encoders, and more. The most focused, authoritative book available in the field, Capacitive Sensors brings you complete information on the research, design, and production of capacitive sensors. This all-in-one source provides detailed, comprehensive coverage of key topics, including underlying theory, electrode configuration, and practical circuits. In addition, you'll find reviews of a number of tested systems never before published. Capacitive Sensors is a must-have for product designers and mechanical and electrical engineers interested in using this fast-developing technology to get top price and performance advantages.

1.1 Overview of Lab-on-Chip Laboratory-on-Chip (LoC) is a multidisciplinary approach used for the miniaturization, integration and automation of biological assays or procedures in analytical chemistry [1–3]. Biology and chemistry are experimental sciences that are continuing to evolve and develop new protocols. Each protocol offers step-by-step laboratory instructions, lists of the necessary equipments and required biological and/or chemical substances [4–7]. A biological or chemical laboratory contains various pieces of equipment used for performing such protocols and, as shown in Fig. 1.1, the engineering aspect of LoC design is aiming to embed all these components in a single chip for single-purpose applications. 1.1.1 Main Objectives of LoC Systems Several clear advantages of this technology over conventional approaches, including portability, full automation, ease of operation, low sample consumption and fast assays time, make LoC suitable for many applications including. 1.1.1.1 Highly Throughput Screening To conduct an experiment, a researcher fills a well with the required biological or chemical analytes and keeps the sample in an incubator for some time to allowing the sample to react properly. Afterwards, any changes can be observed using a microscope. In order to quickly conduct millions of biochemical or pharmacolo- cal tests, the researchers will require an automated highly throughput screening (HTS) [8], comprised of a large array of wells, liquid handling devices (e.g., mic- channel, micropump and microvalves [9–11]), a fully controllable incubator and an integrated sensor array, along with the appropriate readout system.

This book describes ultra low power capacitive sensor interfaces, and presents the realization of a very low power generic sensor interface chip that is adaptable to a broad range of capacitive sensors. The book opens by reviewing important design aspects for autonomous sensor systems, discusses different building blocks, and presents the modular architecture for the generic sensor interface chip. Finally, the generic sensor interface chip is shown in state-of-the-art applications.

In a world where great efforts are spent designing and creating more complex, yet efficient systems, sensing elements and related readout circuits, which constitute an integral part of them, need to be designed fulfilling these constraints, beside the common key parameters, such as high sensitivity, resolution and accuracy. Capacitive sensors and their differential subset provide virtually no energy dissipation, show insensitivity to temperature variations and have the capability to be micromachined directly onto a silicon substrate, together with the readout interface. Designing a readout circuit that takes advantage of these benefits, according to any specific application, is thus of utmost importance. This volume introduces the reader to state-of-the-art techniques and research achievements in interfacing differential capacitance sensors. Technical topics discussed in the book include:▪ Switched capacitor based interfaces;▪ Voltage mode, differential capacitance to time, voltage, digital converters;▪ Current mode interfaces based on standard components;▪ Current mode interfaces based on CCIIs and VCIIs;▪ Principles of second generation current and voltage conveyors. This book gives the reader a comprehensive overview on the working principles, equivalent circuit models and most advanced interfacing techniques for differential capacitive transducers, highlighting benefits and downsides of each option. Electronic interfaces for differential capacitive sensors is an ideal text for academic staff and Masters/research students in electronic and microelectronic engineering.

Sensor technologies have experienced dramatic growth in recent years, making a significant impact on national security, health care, environmental improvement, energy management, food safety, construction monitoring, manufacturing and process control, and more. However, education on sensor technologies has not kept pace with this rapid development

* Sensor technology is an increasingly important area of research * This will be the only book entirely devoted to the topic

This book gathers the best papers presented at the Third Italian National Conference on Sensors, held in Rome, Italy, from 23 to 25 February 2016. The book represents an invaluable and up-to-the-minute tool, providing an essential overview of recent findings, strategies and new directions in the area of sensor research. Further, it addresses various aspects based on the development of new chemical, physical or biological sensors, assembling and characterization, signal treatment and data handling. Lastly, the book applies electrochemical, optical and other detection strategies to relevant issues in the food and clinical environmental areas, as well as industry-oriented applications.

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.