“While 3D printing allows for many users to create complex geometries not before possible, 4D printing does that and more with materials and textures that respond to their environment and then revert to their original shape when exposed to other features like temperature. Zhizhou Zhang, Kahramen G. Demir, and Grace X. Gu (all from University of California, Berkeley) explore 4D printing and all its surrounding details in…”
Source:
https://3dprint.com/239211/berkeley-researchers-exploring-progress-challenges-4d-printing/