Graphene is a 2 dimensional material made of a single layer of carbon atoms that are bonded together in a repeating pattern of hexagons. It has amazing properties, which compelled scientists to give it the title “miracle material”: Graphene is extremely strong and almost entirely transparent, while also being astonishingly conductive and flexible. It is made of carbon, which is abundant, and should eventually become a relatively inexpensive material. Graphene has a seemingly endless potential for improving existing products as well as inspiring new ones.
While graphene indeed has exceptional electronic, mechanical, and thermal properties, a major challenge in using those properties lies in finding the right fabrication techniques that allow the direct manipulation of the material. Inkjet printing, for example, is a much-researched technique where liquid-phase graphene dispersions are used to print conductive thin films. It proves to be interesting, but lacks the ability the design 3D graphene structures.
As opposed to that, 3D printing could be the key to doing exactly that – marrying the advantages of three dimensional manufacturing with the outstanding potential of nanotechnology. Researchers at Northwestern University developed a solution-based graphene ink that can be 3D-printed under ambient conditions via simple extrusion into arbitrarily shaped, electrically conductive, mechanically resilient and biocompatible scaffolds with filaments ranging in diameter from 100 to 1000 µm. The resulting material is very flexible and can be easily printed into small or large scale (multiple centimeters) objects. This technique, according to the researchers, holds the potential for printing electronics and even body parts!.
The printed objects contain a high level of graphene while maintaining structural integrity, which is enabled by the particular biocompatible elastomer binder – PLG – that was chosen in combination with the solvent system. This could be a revolutionary method for producing biomaterials for nervous tissue regeneration, and also biomaterials that are scalable and relatively inexpensive to produce. The novel 3D printable graphene inks are reportedly quite easy to produce, can be rapidly fabricated into an infinite variety of forms (including patient specific implants), and are also surgically friendly (can be adjusted to size and sutured to surrounding tissue).
The scientists claim to have demonstrated the ability of their method to induce neurogenic differentiation of adult mesenchymal stem cells without the need for any other neurogenic growth factors or external stimuli – a major finding that supports the use of materials for inducing specific cellular responses that can be leveraged for tissue engineering and regenerative medicine applications.
The unique properties of this method could open the door to solving a multitude of medical problems requiring the regeneration of damaged, degenerated or non-functional electrogenic tissues such as nerves, bone, or skeletal and cardiac muscle. Additional medical applications may be implantable biosensors and electrical devices. Outside of medicine, there is potential for use in biodegradable electronics or sensors in consumer products.
Using 3D printing with such innovative materials can usher in a new era in medicine, electronics, sensors and many more fields. Some challenges still remain, like producing the right nano materials and developing methods of handling them, as well as the ability to 3D print different types of materials to create functioning devices. The future, however, seems promising.