Technological advancements in recent years have enabled the development of tiny, cheap disposable and self contained battery powered computers, known as sensor nodes or "motes", which can accept input from an attached sensor, process this input and transmit the results wirelessly to some interested device(s). When a number of these nodes work together, conceivably up to hundreds of thousands, a Wireless Sensor Network (WSN) is formed. Research in the area of wireless sensor networks has become increasingly wid- pread in recent years, partly due to their wide range of potential uses and also partly due to the fact that the technology enabling such networks is now widely available from many di?erent suppliers, such as: Crossbow, MoteIV, Intel and SUN (java based motes). These wireless sensor networks have the potential to allow a level of integration between computers and the physical world that, to date, has been virtually impos- ble. The uses for such networks is almost limitless and include such diverse app- cations as a counter sniper system for urban warfare [1] tracking the path of a forest re [2], determining the structural stability of a building after an earthquake [3], or tracking people or objects inside a building [4], etc.
'Smart' sensors are increasingly being employed, not only in industrial settings, but in every aspect of human life. Sensors are used to monitor health, detect viral infections, select the appropriate cycle for washing machines, monitor traffic, manage intelligent buildings and control processes in a manufacturing plant. Sensors are used to gather a wealth of information from the process that can improve operational efficiency and product quality. Smart sensors include features such as communication capability and on-board diagnostics.
Sensors are now omni-present and ubiquitous. Leading edge research in sensors has been propelled by the advancements made in MEMS technology in the last decade. The scientific world is now on the verge of delivering sensors with radically new capabilities. In many scenarios, multitudes of smart sensors, with limited power and processing capabilities, are being organised in networks to perform more challenging tasks.
This book deals with the theoretical and practical aspects of building, deploying and operating smart sensors. Several informative articles deal with sensor networks, gas and bio sensors, Surface Acoustic Wave (SAW) devices, sensors for health applications, acoustic imaging, home monitoring of elderly people etc. The book is a compilation of the extended versions of the very best papers selected from the many that were presented at the 2nd International Conference on Sensing Technology (ICST 2007) which was held at Palmerston North, New Zealand, from 26-28 November, 2007. Scientist and engineers who work with sensors will find this book very useful and stimulating.
