With unprecedented precision, additive manufacturing technologies such as 3D printing hold great potential for reducing the tons of material resources used in products. In many aboriginal cultures around the world, an artist who sculpts a beautiful statue from a stone is considered to be merely uncovering a form that was already present in the stone. The artist is a tool who enables the form to be uncovered. It's a wonderful, poetic concept that illustrates the beauty inherent in nature. In contrast, western thinking tends to view a carving as the artist’s creation. In either case, if you've been around a sculptor's carving studio, you know there's a lot of material left on the floor. These tailings, or scrap, are pieces of the original stone that had obscured the desired form.
The carved sculpture is an example of subtractive technology. The desired outcome, or form, is extracted from a seemingly irrelevant environment (the part of the stone that's not needed). To a degree, the ancient idea of discovering hidden beauty - or wealth - embedded in the rock and wresting it from its environment is reflected in our thinking about economics, manufacturing, technology, and even education.
We acquire valuable resources from the earth by digging up huge quantities of raw materials and extracting what we want from it. We take "crude" oil and subtract out the irrelevant or useless parts, refining it to get to the unique molecular forms we call fuels. We extract critical metals and minerals from ores by crushing and separating out the parts we don't want.
Subtractive processes remove undesired materials to achieve desired forms. On a large scale, this results in big environmental problems. There are many other examples of subtractive manufacturing processes. A substantial portion of "consumer" product manufacturing involves stamping, cutting and grinding, settling, filtering, flaring, and boiling-off processes that remove what isn't needed to get to a desired essence.
On the other hand, additive manufacturing has to do with combining multiple elemental components, each of which is usually obtained through subtractive processes. One of the earliest examples is a hatchet composed of a carved wooden handle tied with reeds to a carved stone arrowhead. The formation of alloys like bronze (made from combining copper and tin under heat as early as 3000 BCE) is another good example, as is forming brass from combining copper and zinc.
Additive and subtractive processes are reflections of processes found throughout nature. The processes of life, collectively called metabolism (meaning change), fall into two simple sub-categories: (1) Catabolism: the breaking down of complex substances into simpler parts that are needed for certain functions; and (2) Anabolism - the building up or combining of simple parts into new complex forms that are also needed. Sound familiar?
Engineers around the world are studying how nature solves problems and using that knowledge to facilitate innovation in technology. In a few short years, this work has led to revolutionary new techniques for replacing often toxic and wasteful large-scale manufacturing technologies with elegant, simple, and resource-efficient solutions.
What's new in additive and subtractive technologies - and what holds so much hope for dMASS - is unprecedented precision resulting from our newfound abilities to reorganize resources at the nano-scale, or the scale of individual atoms and molecules. To a large degree, the reorganizing at this scale is done by nature itself, meaning there is more potential now for product lifecycles to require far fewer fossil fuels and tons of material resources.
3D printing refers to a process that works much like a desktop printer, but it prints finished products. Instead of ink, a 3D printer uses a carefully-calculated and measured combination of basic elements that bond together as they are laid down, layer by layer. There is very little scrap (manufacturing waste) because the molecular formations comprising the outcome are added so precisely that the product appears in the exact shape desired. Moreover, because the equipment for 3D printing itself is getting smaller, lighter, and less expensive, it will enable manufacturing to move back closer to users, which can reduce total lifecycle fuel use.
We have written extensively about 3D printing and other additive layer manufacturing (ALM) technologies in our dMASS newsletters and will continue to do so. These technologies have almost unimaginable potential to generate wealth with fewer overall tons of waste per capita or production unit, thus drastically extending the life of our available resources. Although it is clear that they have their own significant environmental challenges, which I will discuss in future article and which must be addressed with the same creativity that is going into development of nano-manufacturing, there is no question that their continued development is the only way to expand prosperity for a growing population given an intensifying resource supply problem.