Campus Technology reports on a recent paper published by Advanced Materials Technologies, a Wiley journal. This paper was written by researchers at MIT, who have been funded by a National Science Foundation grant.
These researchers, “led by post-doctoral fellow Sebastian Pattinson,” were attempting to “come up with a possible renewable and biodegradable alternative to the more commonly used ABS and PLA [3D] printing materials.”
And they succeeded!
The MIT researchers discovered a way to 3D print in cellulose, “the same abundantly available fiber that gives plants their structure…cellulose is already used for that most common of printing medium – paper. But until now, efforts to use it as an ingredient in 3D printing have run into snags.”
“One problem is that 3D printing requires heating up the printing material to make it flowable; but cellulose tends to decompose when it’s heated, owing in part to the destruction of its hydrogen bonds. Also, the bonding among cellulose molecules in high-concentration cellulose solutions creates a polymer that is too sticky for 3D extrusion.”
In order to bypass these obstacles, Pattinson and his team “worked with cellulose acetate, a composition that’s easily made and widely available and that can be used at room temperatures… [in this new MIT developed process,] cellulose acetate dissolves in acetone and pours through a nozzle. As the acetone evaporates, the cellulose acetate solidifies into place. A subsequent optional process increases the strength of the printed parts.”
“To demonstrate the ‘chemical versatility’ of the printing process using cellulose, Pattinson and his team added a touch of antimicrobial dye to the cellulose acetate ink and 3D printed a set of antimicrobial surgical tweezers.” Pattinson suggested “this type of custom tool could be useful for remote medical settings where surgical tools are difficult to obtain and where the sterility of the operating room isn’t ideal.”
Pattinson concludes: “Cellulose is the most important component in giving wood its mechanical properties. And because it’s so inexpensive, it’s bio renewable, biodegradable, and also very chemically versatile. It’s also highly common. Cellulose and its derivatives are already used in pharmaceuticals, medical devices, as food additives, building materials, and clothing. A lot of these kinds of products would benefit from the kind of customization that 3D printing enables.”
Image and Quotes Courtesy of MIT and Campus Technology