July 17, 2017: Scientists at MIT have changed the concept of 3D printing. Usually, the 3D objects, after printing remained static. But MIT scientists have changed that concept.
The scientists developed a way to print objects, to which, they can go back and add new polymers that alter the chemical composition and mechanical properties of the object. They also developed a way to fuse two or more printed objects together to form more complex structures.
This was possible with LEDs. By using blue light from an LED, the MIT scientists could change the shape of a 3D printed object, and it even larger.
The scientists wanted to expand the complexity of the objects that can be created by using 3D printing, thus opening new opportunities where 3D printing could be used.
Now, one can print a material, take that material by using light, and fuse the material into something else, or grow the material further, said Jeremiah Johnson, the Firmenich Career Development Associate Professor of Chemistry at MIT.
3D printing uses a technique called “living polymerization,” where the growth of the materials can be stopped and then restarted later. MIT tested this by using ultraviolet light to add new features to 3D printed materials, which created reactive molecules called free radicals. These radicals bond to new monomers from a solution incorporating them into the original material. However, this approach damages the material, which the scientists find difficult to control.
Hence, the scientists developed new polymers that are also reactivated by light, and act like a folded up accordion. When blue light from LED shines on organic catalysts, chemical groups called TTCs get attached to the new monomers, making them to form new properties. As a result, the researchers could make the materials more rigid, and could swell and contract as per the temperature. They could also merge two structures together by shining LED light on them.
Since, the technique works only in an oxygen-free environment, MIT scientists are now testing other catalysts that can be used in the presence of oxygen, and will accomplish the same results.