Sensors and Actuators using polymeric systems is one of the most promising fields of "Intelligent Polymers," which is becoming more and more important associating with artificial sensing and actuating systems in living organisms. Some practical applications have now started to test in industry. The book covers optical, gas, taste, and other sensing systems using various kinds of polymers. Soft and wet actuating systems using polymer gels and networks are another field which caused excitation in the last year. The contributors are all pioneers in the field, and were selected from world-wide level. They provide the necessary background information and science to develop a basic understanding of the field, its supporting technologies and current applications. Besides, the overviews will provide a sense of how these supporting technologies can be combined to meet the requirements of advanced systems. Finally, the readers will learn about potential future developments.