Researchers at Northwestern University designed a method to print 3D structures using graphene nanoflakes, by developing a graphene-based ink that can be used to print large, robust 3D structures. This fast and efficient method may open up new opportunities for using graphene printed scaffolds and various other electronic or medical applications.
The relatively high volume of graphene flakes in the ink (60-70%), combined with the use of bio-compatible elastomer and evaporating solvents, grants the material electrical conductivity and mechanical strength, without making the printed objects brittle. Once the ink is extruded, one of the solvents in the system evaporates right away, causing the structure to solidify almost immediately. The presence of the other solvents and the interaction with the specific polymer binder chosen also has a significant contribution to its resulting flexibility and properties. Since it holds its shape, it is possible to build larger, well-defined objects.
The research team injected one of the scaffolds with stem cells and received surprising results. Not only did the cells survive, they also divided, proliferated, and morphed into neuron-like cells. This sort of function can open the door to many desirable medical applications. The printed graphene structure is also flexible and strong enough to be easily sutured to existing tissues, so it could be used for biodegradable sensors and medical implants.
In April 2013, Northwestern scientists developed a novel approach to inkjet printed graphene inks.