Three-dimensional printing, also known as additive manufacturing,
takes a digital blueprint and turns it into a physical object using
computer-aided design (CAD).The process of 4D printing is
essentially the same – it utilizes the same 3D printers, and the
computer runs the same program to deposit material in
successive layers until a 3D structure is formed. However, 4D
printing adds a new dimension, where the structure can change its
shape over time.