The book contains lectures presented during the meeting "1st caesarium" held on the topic "Smart Materials" 1999 in Bonn. Recent results in theory and engineering of smart materials were discussed. Special emphasis was put on thin film technology and its role in sensor and actuator applications. This book will be of particular interest to physicists, engineers and mathematicians working in academia as well as in industry on the field of new materials with special interest in finding intelligent solutions of complex technological problems.