While there has been some progress lately in extrusion-based graphene 3D printing (with Graphene Labs going as far as to announce a graphene enhanced filament as close to market), the research around the actual possibilities offered by graphene in many fields is only at the beginning. A new study, conducted by researchers at London’s Imperial College and other universities throughout Europe, found that, by properly combining CMG (Chemically Modified Graphene) with a BCS (Branched Copolymer Surfactant), it is possible to give filament made entirely out of graphene the necessary qualities to successfully 3D print complex microstructures.
This allowed the researchers to create a microstructure made entirely of graphene. While this is something that has already been done for simpler shapes like cylinders and cubes, through processes such as free casting or emulsion templating, this is the first time that this has been accomplished through 3D printing to form a geometrically complex, graphene monolith.
The study sought to give graphene the correct viscoelasticity for it to be able to maintain its shape after extrusion, sustain the weight of a microscopic printed part without deformation, and exhibit good adhesion between each new layer. The BCS was used to create “responsive”, chemically modified graphene sheets, namely, in this case, sheets of graphene oxide (GO) and its reduced form (rGO). Graphene is generally extremely hydrophobic, which makes it difficult to create an “ink” with it. Through this technique, the graphene sheet’s interactions in water could be regulated using pH as an external stimulus.
As Dr. Esther Garcia-Tuñon, a Research Associate at the Centre for Advanced Structural Ceramics at Imperial College London (ICL), wrote in the paper, published in Advanced Materials, this allowed the team of researchers to obtain a graphene-based ink which could be extruded through nozzles with diameters between 500 and 100 microns to form self-supporting 3D structures. Carefully regulating the interactions between the graphene sheets in a suspension allowed the scientists to continuously extrude a graphene ink with a very specific rheological behavior. After the structure was completed, it underwent a specific treatment to recover the graphene’s properties.
The entire process is based on establishing the correct calibration of pH in order to optimize the GO’s 3D printing properties and could yield very promising results in terms of 3D printable applications: the wonder material of the future and the wonder manufacturing technology of the future, it seems, will “GO” together after all.
