Book excerpt: Smart Materials in Additive Manufacturing, Volume 1 provides readers with an overview of the current smart materials widely in use and the techniques for additively manufacturing them. It demonstrates the principles developed for 4D printing in a way that is useful for students, early career researchers, and professionals. Topics covered include modeling and fabrication of 4D printed materials such as dielectric elastomer soft robots, low-voltage electroactive polymers, and stimuli-responsive hydrogels. 4D printing of light-responsive structures, gels and soft materials, and natural fiber composites are also discussed, as is origami-inspired 4D printing, 4D microprinting, and reversible 4D printing. 4D bioprinting and related biomedical applications are outlined as well as functionalized 4D printed sensor systems. Key Features:* Discusses 4D printed shape memory polymers, shape memory alloys, natural fibers, and hydrogels* Covers various types of stimuli, fabrication techniques, multi-physics modeling, and control strategies for 4D printing* Explores 4D printing of dielectric elastomers, liquid crystal elastomers, and electroactive polymers - Covers the mechanics, manufacturing processes and applications of 4D-printed smart materials and structures - Discusses applications in civil, mechanical, aerospace, polymer and biomedical engineering - Presents experimental, numerical and analytical studies in a simple and straightforward manner, providing tools that can be immediately implemented and adapted by readers to fit their work