Book excerpt: Chemical Sensor Technology is a series of annual reviews reporting the latest progress being made in research and technology, both basic and applied, regarding chemical sensors. Chemical sensors continue to grow rapidly in importance encompassing a broad spectrum of technologies covering safety, pollution, fuel economy, medical engineering and industrial processes. Various types of chemical sensors have been devised for detection and monitoring of chemical substances in gases, solutions and organisms, and much work is being done to produce sensitive, selective, reliable and inexpensive sensors. The series aims at contributing to the progress of research and development of chemical sensors. Contributors to the individual volumes are carefully selected by an international editorial board who ensure that as many innovative studies as possible are included. Each article describes a specific topic and is the original work of an expert working in the front lines of chemical sensor research. Contributors are encouraged to describe not only the academic or technological essence of the subject, but also the background and philosophy, evaluation and achievements and future problems. In this way, each topic is described in sufficient depth so as to be useful and stimulating to readers.