3D and 4D Printing Technologies: Innovative Process Engineering and Smart Additive Manufacturing

Three‐dimensional (3D) printing, also known as additive manufacturing or rapid prototyping, is a manufacturing process that is used to create a three‐dimensional solid object from a 3D digital model. In the medical field, 3D printing technologies have been used for the production of personalized medicines, oral dosage forms, medical devices, and tissue engineering applications. This chapter explores the different types of 3D printing technologies: stereolithographic 3D printing, powder‐based 3D printing, selective laser sintering, fused deposition modeling (FDM), semisolid extrusion 3D printing and thermal inkjet printing. The FDM 3D printing can be considered the most low‐cost and easily accessible technology among all 3D printing techniques. Hot melt extrusion is the process of forming a newmaterial by heating and melting a raw material, most of the time polymers, and then forcing the melted material through a die under controlled conditions. Materials that are used in four‐dimensional (4D) printing are called smart materials.