​​​Additive manufacturing technology, also known as 3D printing, has shown tremendous growth and development over the last few years.

Today it is possible to print not only plastic prototypes, but serious functional end-use mechanical parts can be produced in a variety of material types including a large range of polymers, composites, ceramics and metals. While it is an expensive process, the main advantage is the complexity of design that can be realised by this method. This is where biomimicry comes in.

Biomimicry is “innovation inspired by nature," or “the conscious emulation of nature's genius", as described by Benuys in 1997. Nature has been optimising complex, beautiful and functional structures over more than 3.8 billion years, so it makes sense for us to learn from these structures and use the principles for engineering design.

A team of researchers led by Prof Anton du Plessis from the Department of Physics at  Stellenbosch University, compiled a comprehensive review of the topic of biomimetic design for additive manufacturing, focusing on functional end-use parts. The paper,  titled “Beautiful and Functional: A Review of Biomimetic Design in Additive Manufacturing" was published in the journal Additive Manufacturing this month.

The authors present a summary and categorisation of the different forms of biomimicry currently in use in this field, highlighting the advantages of each approach by using examples from the recent literature. Most of the examples are focused on metal parts produced using the technique of laser powder bed fusion, a special form of additive manufacturing allowing especially high-detail and complex designs. However, the principles and especially the categorisation of biomimetic approaches are applicable to all forms of 3D printing. For example, the graphical abstract of the paper demonstrates an example of a metal part (titanium alloy) designed using a combination of two biomimetic design approaches: simulation-driven design and latticing (cellular design). The simulation-driven design process starts with structural mechanical simulations in an initial design space, to identify the areas of highest and lowest stress, and removes material in low-stress areas. This is followed by another iteration of simulation and the removal and addition of material. This iterative process is similar to evolutionary processes in nature, where in each iteration an improved structure is revealed. Finally, the lattice design is itself similar to cellular structures in nature, such as cork or wood cells, but optimised here for providing not only lightweight but also good stiffness of the structure.

For more information on this work please access the paper here: https://doi.org/10.1016/j.addma.2019.03.033

Or contact the lead author here - Prof Anton du Plessis – anton2@sun.ac.za

Research group: http://blogs.sun.ac.za/duplessis/

On the images above, an example of a biomimetic titanium bracket – the obvious advantage here is light-weighting of the structure compared to a traditionally designed component. The result is both beautiful and functional. Image: Anton du Plessis