For centuries, cellulose has formed the basis of the world’s most abundantly printed-on material: paper. Now, thanks to new research at MIT, it may also become an abundant material to print with—potentially providing a renewable, biodegradable alternative to the polymers currently used in 3D printing materials. “Cellulose is the most abundant organic polymer in the world,” said MIT postdoc Sebastian Pattinson, lead author of a paper describing the new system in the journal Advanced Materials Technologies. The paper is co-authored by MIT associate professor of mechanical engineering, A. John Hart.
Cellulose, Pattinson explained, is “the most important component in giving wood its mechanical properties. And because it’s so inexpensive, it’s biorenewable, biodegradable and also very chemically versatile; it’s used in a lot of products. Cellulose and its derivatives are used in pharmaceuticals, medical devices, as food additives, building materials, clothing—all sorts of different areas. And a lot of these kinds of products would benefit from the kind of customization that additive manufacturing enables.”
Using cellulose as a material for additive manufacturing is not a new idea, and many researchers have attempted this but faced major obstacles. When heated, cellulose thermally decomposes before it becomes flowable, partly because of the hydrogen bonds that exist between the cellulose molecules. The intermolecular bonding also makes high-concentration cellulose solutions too viscous to easily extrude. Instead, the MIT team chose to work with cellulose acetate—a material that is easily made from cellulose and is already widely produced and readily available.