Book excerpt: 4D Printing: Fundamentals and Applications explores both autonomic and non-autonomic systems with different stimulus such as temperature, current, moisture, light and sound. In addition, the fifth dimensional aspect using more than one stimulus is outlined for additive manufacturing processes. The book presents both an introduction to the basic understanding of hybrid processes and explores the physics behind the process (in the form of derivation and numerical problems). For the field engineer, applicable codes and standards for each hybrid process are provided. Lastly, case studies are included in each section to provide the reader with a model to explore future research directions. - Begins with the fundamentals of the hybrid additive manufacturing process - Presents a discussion of the physics behind smart material functioning in hybrid additive manufacturing - Includes real world case studies on 4D and 5D printing, as well as a look at future research dimensions