Digital render of a 3D-printed jaw implant by Deviaene. Image credit: www.dezeen.com
The hype surrounding 3D printing has swelled substantially in the past few years, largely driven by accessible design platforms, customisation and distributed manufacturing. While aesthetic design applications can be fascinating in their own right, are all of the functional benefits of 3D printing technologies receiving the attention they deserve? 3D printing is still seen as more of a ‘soft’ manufacturing process suited to prototypes and less functional parts, but many do not realise that the technology offers the potential to make functionally superior parts to traditional methods for certain applications.
No sector seems to offer more untapped potential in this regard than the medical industry, where 3D printing applications are currently fairly limited but are expected to reach over $2bn by 2020.
While rapid prototyping using 3D printing technology is now well established and extremely useful for rapid iterative design development, additive manufacturing – the production of end-use parts using additive processes – still offers a huge opportunity for continued growth of the 3D printing industry. Additive manufacturing offers a number of key benefits over alternative technologies:
• No tooling requirement – the next part can be geometrically completely different from the last, with no time/cost penalty
• Minimal waste process (except where support material is required) – more economical and environmentally friendly
• Unparalleled geometric freedom – designs are not restricted by tool access or material flow limitations
• Flexibility – using a single, compact machine to produce any number of different parts enables easy collaboration across supply chains and the potential for distributed manufacturing, even at point of sale
However, the ability to produce end-use component parts and assemblies has historically been limited by a number of factors:
• Narrow range of usable materials, often with inferior properties to those available when using alternative manufacturing techniques
• Lack of economies of scale when producing greater numbers of parts leading to high production costs
• Difficult to achieve tolerances and surface finishes comparable to machined or moulded parts
• Lack of software and hardware availability for design optimisation techniques to unlock the potential of the technology
The good news is that many of these barriers are falling fast as investment into 3D printing technology and supporting systems increases. As a result, not only is additive manufacturing becoming competitive in a growing range of existing applications, but also in areas where the technology is driving new possibilities for products and services. An example that has seen a lot of attention in the press recently is 3D printed organs and tissue. The geometric freedom of 3D printing and the ability to produce complex hollow structures allows unrestricted design that has simply never been possible using other manufacturing technologies.
Such geometric freedom comes with a caveat. When the manufacturing process is no longer restrictive, the limiting factor becomes the capability of the software available – or the imagination of the person driving it. The true technical potential of additive manufacturing comes from its ability to enable new design and implementation opportunities (and this isn’t just about allowing designers to make funky looking lampshades!). Using design optimisation algorithms built into CAD packages, geometries can be created that provide improved functionality and reduced weight, cost and environmental impact. Finite element analysis (FEA) has already become the go-to for engineers looking to analyse loading conditions on a part; the next logical step is to feed the outputs back into the design to automatically create the optimal part geometry for a given space envelope and set of conditions.
Design optimisation and 3D printing of structural component. “Construction steelwork makes its 3D printing premiere”, Arup. Image credit: www.arup.com.
While the principle of design optimisation is not new, the consistent increase in available computing power is likely to facilitate widespread adoption over the next decade as the technology becomes accessible to a broader base of engineers and designers. This conveniently ties in with the continued growth of 3D printing as an enabling manufacturing process.
So, where might we expect to see additive manufacturing processes applied in the near future? There are a number of contributory factors that make medical devices a promising application, not least of which the fact every human body is unique. Products requiring customisation such as implants, braces and hearing aids already utilise additive manufacturing and have driven the development of new printable materials such as trabecular titanium that facilitates healing. Anything that is carried on the body can also benefit from weight savings through design optimisation to offer devices that are minimally invasive to their users.
Trabecular Titanium Implant. “Arcam Metal 3D Printers Making Titanium Implants on Sicily’s Etna Volcano”, 3D Printing Industry, Davide Sher. Image credit: 3dprintingindustry.com
Design optimisation is also not just for structural designs – fluidic devices could benefit from optimised flow paths printed in a single part, for example in ‘lab on chip’ products. Such devices have traditionally been difficult to fabricate and correspondingly restricted to largely 2D flow paths, however an additively manufactured solution utilising design optimisation techniques could offer substantial benefits – reduced package size, more complex functional capabilities and increased design freedom.
It’s always interesting to keep track of technologies that have the potential to change the way that we approach design and engineering challenges, keeping in mind that the landscape is constantly changing and that ideas that may appear infeasible now may become relevant in the future. Design optimised additive manufacturing is just one of the technologies on the roadmap that could have this effect.
Posted by Simon
Consultant – Engineering Design
Languages spoken: English, a bit of French.
The last thing that inspired me: A stovetop coffee maker.
My dream project: Designing and building an unregulated racing bicycle.
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