3D Printing with minimal ingredients and steps forSustainability [Video]

A new 3D printing method developed by engineers at the University of California San Diego is so simple that it uses a polymer ink and salt water solution to create solid structures. The work, published in Nature Communications, has the potential to make materials manufacturing more sustainable and environmentally friendly.

The process uses a liquid polymer solution known as poly(N-isopropylacrylamide), or PNIPAM for short. When this PNIPAM ink is extruded through a needle into a calcium chloride salt solution, it instantly solidifies as it makes contact with the salt water. Researchers used this process to print solid structures with ease.

This rapid solidification is driven by a phenomenon called the salting-out effect, where the salt ions draw water molecules out of the polymer solution due to their strong attraction to water. This removal of water causes the hydrophobic polymer chains in the PNIPAM ink to densely aggregate, creating a solid form.

“This is all done under …