Getting Smart About 3D Printing
How do materials fit into a ‘smart system’ where new manufacturing technologies and techniques assist innovation without coming into conflict with the principles of a regenerative circular economy.
From the Editor:
Designing waste out of the economy and creating more effective flows of resources is a significant challenge faced by today’s economy, particularly in a context where there are large quantities of and variations of materials all in use and all in circulation. Many products contain high value components that are worth reusing, but they cannot be cycled effectively because of complex materials mixes. Humans already use around 350 polymers and that number is still growing. In contrast, as Janine Benyus’ work in Biomimicry emphasises, there are only five core polymers in the natural world. In nature, innovation and adaptiveness comes through the layering and architecture of structures, rather than through the creation of new types of materials.
Alysia’s article examines these issues in the context of the growing popularity of 3D-printing as a design and manufacturing solution. The possibilities for new materials and material mixes in 3D-printing are ever expanding and they bring new opportunities with them, but just as important in the development of manufacturing will be the application of biomimetic thinking on the value of selective and simplistic material selection.
We’re accustomed to thinking of materials as just physical ‘stuff’, to be shaped and cut and worked according to our will. However, as the manufacturing process is digitalised, the idea of materials as a passive input for the things that we make is changing. ‘Smart’ manufacturing can involve digital design, automation, supply-chain management, and product tracking. How ‘smart’ can the actual materials become? This is where 3D printing comes in.
Chris Anderson, author of The Long Tail and former Editor-in-Chief of Wired magazine, says that 3D printing is the digital revolution meeting the physical world. Fundamentally, this challenges the traditional separation between the information and materials flows that are a part of circular economy models. This article explores this idea by looking at how information is being encoded into the material world in new ways through 3D printing. The opportunity that arises for the circular economy is through the potential to increase the performance characteristics of products that are made from recyclable materials. However, if 3D printing innovation is not directed by systems thinking, we could speed up the linear economy by feeding industry higher quantities of mixed materials that are more difficult to cycle back into production.
To understand both challenges and opportunities, let us first look at the landscape of 3D printing materials. 3D printing (also referred to as Additive Manufacturing) is a large family of technologies that use heat, light, binders, or pressure to build up materials layer by layer according to a Computer Aided Design (CAD) file. The range of materials used in these processes is broad and includes plastics, metals, ceramics, and composites. Complementing that mix is an array of chemical additives that alter behavioural characteristics such as colour and elasticity. For instance, industrial grade 3D printers have produced multiple colour outputs for years, and now desktop machines are catching up.
For the circular economy then, the challenges of cycling 3D printing materials and traditional manufacturing materials should be similar. But are they? One could argue that with 3D printing it’s not what materials we’re using, but how we’re using them. An important difference between how traditional manufacturing and 3D printing relate to materials is the way they are able to integrate information into the materials themselves.
As the 3D printer adds each layer of material, information can also be added. This is the secret to the complex internal geometry of some 3D printed objects, but it is also the key to manipulating material microstructure, such as adding lattices or honeycomb patterns at nano scale. Harvard University researchers are mimicking the complex composition and behaviour of balsawood with the combination of specially engineered 3D printing ‘ink’ and the integration of structural patterns.
“If 3D printing innovation is not directed by systems thinking, we could speed up the linear economy by feeding industry higher quantities of mixed materials that are more difficult to cycle back into production.”
Layering materials also allows digital information to be designed into an object in new ways. Voxel8, a 3D-printing company, recently introduced the first ‘3D electronics printer’, where the structural plastic and conductive ink can be blended to literally ‘print electronics’. Although integrating electronics into objects is far from novel, closing the gap between the physical and digital through the process of manufacturing is significant.
These examples introduce some of the ways that 3D printing can combine materials and information. Yet what if that information were lost? The take-make- dispose economy is one where information is lost and materials are wasted. Herein lies the critical challenge for the circular economy: how are we going to keep all this material information, from nano-engineered composites to electronic ink-polymer mixes, in circulation? Rephrased, as 3D printing blurs the distinction between information and material flows, how can we design materials and products for the circular economy?
Addressing this challenge means creating new performance characteristics of 3D printed products without using complex mixes of materials that are difficult to keep in circulation. It means taking advantage of the structural complexity introduced by 3D printing systems, while using simple material ingredients. Happily for us, other organisms have solved this issue. Most plants and animals develop through additive processes that provide valuable insights for 3D-printing going forward. Take seashells like clams or oysters: they build their shells layer by layer with proteins and calcium carbonate minerals. Or palm trees that grow tall and strong by virtue of varying the density of microstructural layers with height. Electric eels have been channelling electric current for millennia. How does such a diversity of intricate structures and composites not end up as waste?
The answer to this is that other organisms integrate another type of smart into their materials: ‘system smart’. Impressively, they use a subset of the periodic table compared to those we humans use, while creating an abundance of natural materials that often outcompete synthetic materials. The key to this is the smart ways information and material composition interact. From flexible leaves to rigid trunks, organisms have managed to harness the potential of integrating information into material fabrication, so that the basic building blocks they use can be assembled to produce an incredible variety of material performance characteristics. Yet the materials created are also ‘smart’ from a systems perspective cycling within the ecosystem as nutrients.
This is the challenge and opportunity that 3D printing presents us with. Unlike ever before, humans can layer information into our material world to create novel material functionality. Yet, unless these smart materials are designed within a smart system, we risk more and more information being lost, as our products and all of the materials and components contained within them become waste. As the digital revolution meets the material world, how we handle information will be important in ensuring that 3D-printing is an enabler in the transition to a circular economy.