4D printing is entirely possible and represents an advanced evolution of standard additive manufacturing where printed objects utilize programmable smart materials capable of changing their shape, color, or structural properties over time when exposed to specific external environmental stimuli such as heat, moisture, light, or pressure. Researchers and commercial manufacturers across aerospace, defense, and biomedical engineering sectors actively utilize shape-memory polymers and programmable carbon fibers to produce self-assembling structures and adaptive components that transform post-production.