3D Printing Makes Light Weight 'Gyroid' Structures from Polymer Material

Image by MIT (Massachusetts Institute of Technology

The latest innovation in manufacturing by 3D Printing has been the creation of light weight, high strength material structures called ‘Gyroids’.

Researchers, scientists and engineers at the MIT (Massachusetts Institute of Technology) originally working on the bases of 2D models of Graphene have applied the latest 3D Printing Technology to develop architectural complex geometric structures using conventional polymers.  3D Printed ‘Gyroids’ shaped objects are the latest structural material that could compete with plastic foams and light weight composite. ‘Gyroids’ may have the potential use for structural parts or components for aeroplanes, automobiles and the construction building sector of Industry.

MIT researchers created and designed ‘Gyroid’ structures that were constructed by 3D Printing of Graphene. These have a spongelike configuration which exhibit  5% density of steel and are 10 times the strengths making them the strongest light weight material.

Follow up of experiments originally based on test models and simulations from Graphene, extensively used today, in its 2-dimensional form of carbon and being the strongest material known so far, have challenged scientist at the MIT to make a 3D model by compressing and fusing flakes of Graphene into Gyroids shapes. Their investigations have also lead to the possible use of conventional plastics materials constructed into Gyroid shaped objects that may inherit mechanical properties such as high strength and are light weight. The new structural materials could withstand various compression and deformation forces when subjected to stress and load.

Using the 3D technology researchers were able to predict behaviour of materials by analysing its structure down to its atomic level and developing mathematical framework to produced accurate results for evaluating mechanical and physical properties.

The MIT Scientists constructed 3D cuboid shapes from a conventional Acrylic photopolymer called VeroMagneta supplied by Stratasys Ltd and 3D Printed them from a 20micrometer resolution object500 multimaterial 3D Printer to create these new ‘Gyroids’ shapes. [Fig.1].

Fig 1. Pink cubic shaped Gyroids.

Experimental tests such as compression and failure due to stresses and load were performed by using two Gyroids of varying thickness, each measuring an inch for each side of the cube-like objects.  These Gyroids are porous, 3D, high strength structures comprising of 2D geometries flat sheet like structures that are folded on top of each other as they are created from the 3D printer layer by layer. These when set and cooled create structures with complex geometry and wall thickness. The researchers adjusted wall thickness of each Gyroids and concluded that thin-wall structures fail gradually under compressive load whereas the thicker-walled shapes stored stress as deformation energy and release it suddenly and explosively at the point of failure. Scientists doing the experiments claim 3D Printing is the best way to make an architectural complex geometry from the polymer material. [Fig 2.]

Fig 2. Two Gyroid shapes of varying thickness constructed by 3D Printing under compression test conditions.

The MIT team had work from original models and simulations that were based on Nano-scale arrangements of Graphene. [Fig 3.].

Fig 3. Graphene in its 2D atomic arrangement.

Graphene which is an exotic form of carbon displayed enticing strength and electronic properties at the 2D Nano structures state. The new 3D printed ‘Gyroids’ from a polymer were made at a Macro-size shape and the mechanical proprieties had to be deduced using previous work of Graphene at the Nano-scale models. Graphene was the main material used in early models and simulations and as to predicting strength properties from a Nano-scale to a more useful everyday Macro scale was a challenge. Scaling laws initially derived from nanoscale simulations were used for the macroscale experiments with the use of 3D printing.

According to Gang Seob Jung a graduate student working on the projects and experiments said that the MIT group is working on patenting the technology and as yet not been partnered with any company to commercialise the method. Chemical giant BASF SE in conjunction with the North America Center for Research on Advanced Materials is supporting the project and is providing the resin for the experiments. Jung said the project on the ‘Gyroid’ structures was a follow up of several years of work by the MIT team who experimented on similar topics in designing high-strength microstructure. Markus Buehler was the lead author of the MIT team in a research paper that was published in the peer-reviewed Science Advances journal on the 6^th January 2017 with Jung, Zhao Qin and Min Jeong Kang [2]. In addition to the VeroMagenta polymer the team also worked with a TangoBlack elastomer-type material supplied by Stratasys that mimicked rubber.

The ‘Gyroid’ technology has the potential to compete with plastic foams which currently show high strength-to-weight ratio, but these ‘Gyroids’ have the competitive edge by inheriting a complex architectural geometry which is the dominate factor in determining its superior mechanical properties such as the stiffness, compression strength and light weight. Complex structural material properties of the ‘Gyroid’ is guided dominantly by its geometrical configuration rather than the inherent property of the chosen polymer material, thus it is proposed that many other plastic materials can be used to create light weight component structures that are currently used in the composite industry. ‘This has the potential to transfer to many things’ as stated by Markus Buehler, the head of MIT’s Department of Civil and Environmental Engineering.

References

[1] Image credits MIT (Massachusetts Institute of Technology).

[2] Markus J Buehler, Zhao Qui, Min Jeong Kang, Gang Seob Jung. Science Advances, Jan 6, 2017, Vol.3.  ‘The mechanics and design of a lightweight three-dimensional graphene assembly.