The introduction of 3D printing revolutionized modern technology and its usage has resulted in a number of products, such as prosthetics, to be cheaper and more accessible. Scientists and researchers are currently working on 4D printing technology that would not only help create complex structures with accuracy but will also create materials that would respond to change in temperature or pressure.
Researchers at Harvard John A. Paulson School of Engineering and Applied Sciences and the Harvard Wyss Institute for Biologically Inspired Engineering are working to create 4D printed structures that would change their shape in response to external stimuli. 4D printing is a process through which 3D printed objects can transform themselves into another structure using external stimuli such as a change in temperature, light density or pressure. Using the mechanisms of physics, mathematical frameworks and computation, the researchers have been able to create the most complex shape-shifting structures to date.
In order to form a structure, lattices of different materials are composed that shrink or expand according to the change in temperature. Lattice is an arrangement of isolated points in a regular pattern that shows the position of atoms in the structure of a crystal. In order to demonstrate this technique, the researchers used the face of 19th-century mathematician Carl Friedrich Gauss in order to pay tribute to his work in differential geometry. Using his painting from 1840, the researchers first 3D printed the basic structure of his face and then programmed the lattice points on the structure to grow and shrink to map the curves of his face. In order to give an accurate 3D depiction of Carl Friedrich Gauss’s face, materials with diverse thermal expansion behaviors were used to ensure that shrinkage or expansion of the material would accurately map features and textures of his face.
This design approach and 4D printing method if developed further would create advancements in soft electronics and robots that would be of great help in the medical field. In addition to that, these materials could be used to effectively design buildings and infrastructure to increase safety and make the structures adaptable to natural disasters.