This book offers a systematic review on 4D printing technologies covering from material to design, manufacturing and their applications, and comprehensively presents the state of the art of 4D printing technologies and their applications to soft robots. This book includes 10 chapters. Chapter 1 covers the history of 4D printing, and the key questions and typical examples about applying 4D printing to the field of soft robots. Chapters 2 and 3 introduce the soft active materials and the related 3D printing technologies that are suitable for 4D printing respectively. Chapters 4–8 discuss the typical examples about manufacturing soft robots by different 4D printing technologies. Chapter 9 introduces the recent progress on 3D printing flexible electronics. Chapter 10 outlooks the challenges and directions about the further application of 4D printing technologies to the field of soft robotics. This book benefits the students and researchers from the fields of mechanical engineering, material science, mechanics, robotics, electrical engineering, bioinspired engineering, and other related fields.

Qi Ge is a tenured professor of mechanical and energy engineering at Southern University of Science and Technology, China. Dr. Ge earned his bachelor degree on Engineering Mechanics in 2006 from Tongji University, master degree on Solid Mechanics in 2008 from Zhejiang University, and Ph.D. on Mechanical Engineering in 2012 from University of Colorado at Boulder. From 2013 to 2014, Dr. Ge was a postdoctoral research fellow at Massachusetts Institute of Technology. From 2016 to 2019, he was an assistant professor from Singapore University of Technology and Design. As one of the pioneering scholars on the research of “4D Printing”, Dr. Ge published the first research paper around the world about “4D printing”. His research fields also include multifunctional 3D printing apparatus, smart materials and structures, soft robotics, flexible electronics.

Dr. Kai Yu is an associate professor of Mechanical Engineering at the University of Colorado Denver. He received his Ph.D. in Mechanical Engineering from the Georgia Institute of Technology in 2015. After completing postdoctoral training at Georgia Tech, he joined CU Denver as an assistant professor in 2016. Dr. Yu’s research focuses on the mechanics of polymers and composites that are important to the nation, including recyclable and sustainable polymers, energy-dissipative materials, and shape-changing polymers. He is also interested in integrating these materials with emerging additive manufacturing technologies to broaden their applications, including recyclable 3D printing, 4D printing, and sustainable manufacturing. Dr. Yu has authored more than 120 journal articles and has received several prestigious honors, including the U.S. National Science Foundation (NSF) CAREER Award, the American Society of Mechanical Engineers Rising Star Award, and multiple awards from CU Denver and professional organizations recognizing his excellence in teaching and research.