Intelligent natural systems depend on the communication of signals from their sensing elements to trigger responses. In contrast to synthetic systems that require supplementary devices for regulation, chemo-responsive polymers fuse the sensing and action functions within a single material. This book sets itself apart by concentrating on these innovative materials, such as biosensors that identify viruses and field-effect transistors utilized in biological investigations. Since the previous edition, there has been a notable increase in interest surrounding materials that respond to chemical or biological stimuli, especially in areas such as smart membranes and graphene. Each chapter, penned by leading experts in the field, showcases the extensive capabilities of these materials in a variety of applications, spanning from artificial muscles to precise drug delivery systems.