Now I’ll continue with the subject of Additive Manufacturing with a few more studies that address sustainability. The first part of the listing can be found here. Unlike the first list of studies, which mainly involved quantitative data and experimental testing, from my perspective the studies listed below represent much of the research to date on distributed production: i.e. conceptual explorations and theory building with little empirical data or direct testing in the real world. It’s important to note when these papers are conference papers, as conferences are a good forum for testing and hypothesizing, publicizing interim project results, and doing preliminary studies, sometimes in preparation for a later journal paper. But even some of the journal papers tend to be conceptual discussions that mainly rely on secondary data and/or the literature.

Another useful thing to note, at least for me, is how the authors represent the role of the individual (consumer, end-user, etc.) and what input she is ‘allowed’ to contribute. In mass customization planning this would rather coldly and engineering-ly be referred to as the ‘decoupling point’; in the most visionary conceptualizations of design-for-sustainability where co-design and co-creation are the be-all-and-end-all, non-designers are given much more agency to influence the final output. Or so we are given to think. (A cynical mind might suggest that participatory planning can be used as a foil, to co-opt a populace into accepting a decision that in essence had nothing to do with what the populace wanted, a little thing I like to call ‘participation-wash’. Anyway, moving on, let’s leave this cynicism aside for now.)

There also seems to be a common tendency in the literature on distributed production (including mass customization) to assume that co-creation simply is sustainable: co-design = social sustainability just as meeting exact customer needs through customized products via additive manufacturing = environmental sustainability – without delineating why or how. I’d say we need both more data and better argumentation. Still, all these studies are a good start.

Oh, and hey, I know this isn’t a full list. I started by focusing on specific conferences and journals to gauge the coverage in those platforms and to these audiences in particular. I will add useful and representative studies/articles as I find them in other journals. The first one below is a good example, and something I would have expected much earlier. Hopefully it’s a signpost of more to come.

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This is an article I’ve been waiting for! It’s a bit of a continuation from what Drigo and Preza started in 2006 with their review article. (Check the previous post.) There just seems to be too little discussion of this kind in fora where it might make a difference. (I’m pretty sure that online rants about how 3D printing is going to ruin our precious world amount to preaching to the converted, and the rest of the world carries on regardless.) So I’ll spend a little longer on this article summary.

Huang et al. stick to the roots of additive manufacturing (AM): i.e. the producer viewpoint, the mainly B2B world of digital manufacturing, and not getting into the whole issue of personal fabrication and desktop 3D printers. Section 2 gives a good summary of the various AM technologies themselves and then lists the perceived benefits and drawbacks of AM compared to conventional manufacturing methods (in technical/production terms). The authors don’t give any explanation of how they conducted the literature review itself but somehow they have decided on three main categories, categories that do make sense given their theme of ‘societal impact’ and knowing what we do now about where AM is currently most used.

“Abundance of evidences were found to support the promises of additive manufacturing in the following areas: (1) customized healthcare products to improve population health and quality of life, (2) reduced environmental impact for manufacturing sustainability, and (3) simplified supply chain to increase efficiency and responsiveness in demand fulfillment.”

So sections 3, 4, 5 and 6 discuss these areas respectively. Section 3 (Impact on population health and wellbeing) sums up the studies and applications in this area, but it’s not as interesting to me as section 4, Energy consumption and environmental impact. Here the authors cite a few studies trying to conduct environmental analyses, LCA and Environmental Impact Assessments (EIA) on AM processes – studies that either examine the methods themselves or try to get meaningful results. One study found challenging trade-offs: “new manufacturing processes” could “produce products with longer useful life and/or lower energy consumption during the use phase”, but “make more use of high-exergy value materials in very inefficient ways”. I’m quoting Huang et al. here; this article further quotes the study* itself: “the seemingly extravagant use of materials and energy resources by many newer manufacturing processes is alarming and needs to be addressed….”.

*The study quoted is Gutowski TG, Branham MS, Dahmus JB, Jones AJ, Thiriez A (2009) Thermodynamic analysis of resources used in manufacturing processes. Environ Sci Technol 43:1584–1590.

The authors conclude this section by summarizing a few studies that have examined especially the energy issue, which seems to be the most problematic in comparison to traditional manufacturing, but remind us that too few studies have been conducted to be able to draw firm conclusions. Just before this, the section reviews a few other environmental comparison studies and gives us a couple of useful tables. Table 1 is based on Luo et al. (1999)* and compares traditional machining and various AM technologies, where in the latter we see e.g. less material mass, less pollution, avoidance of other bad stuff entailed in machining such as cutting fluids in waste streams. A few other studies are cited also comparing AM to machining and concluding overall much lower environmental impact from AM. (They’re refs nos. 52 to 55 in the article’s references list.) Table 2 summarizes the conclusions from the ATKINS project report**, a document (and project and research group) that deserves its own section in this write-up. The general conclusion is that, if we compare AM to conventional manufacturing processes “in terms of energy usage, water usage, landfill usage, and the use of virgin materials”, AM has clear environmental advantages in everything except energy consumption, which concurs with pretty much everything else Huang et al. examined. If you don’t check out any other reference or study, do at least have a look at the ATKINS report. (And if you want to know what studies were actually reviewed, check the article’s references list or ask me in the comments to post the references. By the way, I haven’t checked the studies myself so I’m not going to comment on their methods or system boundaries – and I don’t have the expertise to identify methodological problems.)

*Luo YC, Ji ZM, Leu, et al. (1999) Environmental performance analysis of solid freeform fabrication processes. The 1999 IEEE Int Symp on Electron and the Environ. IEEE, NY, pp 1–6

**ATKINS (2007) Manufacturing a low carbon footprint. http://www.atkins-project.com/pdf/ATKINSfeasibilitystudy.pdf. Accessed 16 February 2012.               > The link in the reference seems to be obsolete; try http://www.docstoc.com/docs/36958767/ATKINS-Manufacturing-a-Low-Carbon-Footprint .

OK. Section 5, Impact on manufacturing supply chain, is also interesting to me in terms of monitoring if we are actually moving towards a distributed production paradigm from mass production. (In this context others would prefer the term ‘distributed manufacturing’, but I’m still going to use distributed production to keep the door open to fabbing and making. If I may make yet another diversion, did anyone else notice the disappearance of the ‘Distributed production’ Wikipedia page? We now get redirected to a ‘Distributed manufacturing‘ page, which is much shorter and, I could say, more ‘practical’. Not only that, there was some editorial dispute over whether the page should be deleted altogether. The decision was to keep it, so there it still is. I haven’t yet figured out how to access the now gone Distributed production page.)

Where was I? Oh, yes, supply chains. So the general consensus is that AM processes would change the traditional supply chain, require fewer stages in it, and be thereby able to remove the environmental footprints and impacts of those stages. In this review, researchers tell us that AM technologies are not yet incorporated into especially spare parts supply chains, so two studies cited propose a few approaches or business models for better integration. Another study described four consumer product businesses where consumers order their own customized AM-made stuff. It seems the paper lays out the operations and probably describes the supply chains but doesn’t get into any environmental impact discussion. So this still seems inconclusive, and even fewer studies are being done regarding supply chains.

Section 6 examines Potential health and occupational hazards. This is the hot spot and red light for me, personally, and I regard the authors’ Table 4 (Occupational and environmental effects of different chemicals used in AM processes) to be the best contribution of this paper. They sum up what researchers have concluded in references 67 to 74 (again, ask me in the comments if you want details on these) with regard to human health hazards and biodegradability. They also cite the Drigo and Preza paper (which I mentioned earlier) and state worrying things like:

“Since the majority of the chemicals are long-chain molecules, their biodegradability is very poor and the materials remain in the environment for extended periods of time. Poisonous gases like carbon dioxide (CO2), carbon monoxide (CO), and nitrogen oxides are found to be emanated after the breakdown of these chemicals. It has also been predicted that noxious halocarbons (CFCs, HCFCs, CCl4), trichloroethane (CH3CCl3), nickel, and lead compounds might emerge from the operations of AM machines.”

Since other people will surely, eventually, take care of the problems of worker exposure, there’s no clear incentive to tackle the environmental problems, related to emissions, biodegradability, etc. that may differ from the health hazards. Especially when AM materials start to enter maker spaces in institutions and people’s homes, I’m sure we’ll start to see some awareness raising. Yesterday I attended a 3D printing event in Helsinki and asked an AM expert about the toxicity issues. He said, first of all, that in biomedical applications biocompatibility is obviously considered and his team works with medical doctors and similar experts. With other materials and AM applications, he admitted that there isn’t much research on it. He did add that his team also works with the occupational health and safety authorities in their research, though, so this could be (should be) best practice for any digital manufacturing development team. Note to self: interview this guy later this year.

Ah, I can’t resist yet another diversion. The event I attended was this Audi ADDLab thing, and ADDLab has one of those mcor rapid prototypers that uses ordinary A4 paper and ordinary glue to cut out 3D forms. This does seem to create a lot of paper waste, but the waste AND results can be put into the ordinary paper recycling process (and would not seem to have other unforeseen toxic effects associated with other materials). One of the ADDLab researchers said that, of all the 3D printers they have, and they do have quite a few, they are still exploring with this one to see what it could best be used for. Since it’s subtractive, not additive, you wouldn’t be able to get the complexity of shape as was coming out of the Bits from Bytes behind me, he pointed out. But things like architectural scale models and other types of prototypes seemed obvious and possible: the researcher said that a computer mouse prototype had been done for e.g. ergonomic testing. What is even more interesting is that Staples is using this solution to offer prototyping in their stores, or at least a pilot. I hope someone does a study on their customers and what they do with this service. Ordinary people have office paper recycling in their everyday habits (at least in Finland); they do not have easy access to recycling facilities for Ultimaker, MakerBot, etc. filaments and failed 3D prints. (And this project shows how tricky re-using plastic in a RepRap can be.) (and in English)

OK, returning to Huang et al., the last thing I’ll point out is that the authors are associated jointly with two Chinese universities and the University of Cincinnati. More environmentally responsible digital manufacturing in China could mean a big shift…

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In this article, additive manufacturing has clear environmental benefits and enables much better practice for especially designers but also the consumers they design for. The authors propose that “sustainable product design” needs to focus more on ensuring product longevity in order to combat the environmental problems currently exacerbated by “the consumerist’s ‘throw away’ mentality” and “planned obsolescence”. They allow that in such an emerging field a quantifiable link between product longevity and personalization/customization has not yet been established but anecdotal data seems to indicate this direction. The paper is therefore a conceptual discussion, maybe even a ‘position paper’.

Writing as designers for designers, they offer additive manufacturing technologies and mass customization as increasingly necessary (or inevitable) ‘tools’ in a designer’s toolbox and ways to ensure longevity. They argue that in design, not only the “technical quality” of a product is important but also “the less tangible ‘desirability’ of a product, ‘pleasure of use’ of a product, as well as the ‘attachment’ of a user to a product”. These characterize “design quality”, a notion they argue is neglected in design-for-sustainability. They further argue that mass manufacturing also compromises design quality, through technical compromises that need to be made in design as well as the generic nature of mass-manufactured products.

Therefore, the authors propose, additive manufacturing holds potential to both ensure design quality and better conform to sustainability principles, by lessening the need to compromise and offering a truer realization of the “designer’s vision” (i.e. enhancing design quality from the perspective of professional design) – and by offering mass customization possibilities that can impact the desirability and hence longevity of the product (i.e. enhancing the customer’s perception and reception of design quality). Moreover they wish to support an individual designer’s need for professional development, self-fulfilment, and continued employment; they highlight how product designs must reflect how they are fabricated and that digital technologies will produce new design typologies. The authors conclude by summarizing new considerations when designing for additive manufacturing and indicating future directions for research: the potential need to adapt current design-for-sustainability tools to fit the “new paradigm of on-demand manufacturing” and even possible revision of “some of the frameworks about what constitute sustainability”.

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This is an intriguing article that approaches additive manufacturing from the perspective of materials. The authors aim to examine prosumption (note the explicit use of this term in an engineering context, not a sociological one) through a technological forecasting exercise, putting forth an analytical framework for roadmapping material technologies: their fundamental characteristics and by implication their potential to contribute to the advancement of certain socio-technical practices such as prosumption. In other words, certain materials are restricted by their nature to large processing facilities with significant capital investments and are thus less conducive to distributed production. (Think of steel processing.)

The authors introduce the term “authority” over design and production to describe the agency individuals have to provide design and/or production inputs; they contrast the ability of individuals to acquire original, one-off goods with many mass customization processes that merely offer the ability to “configure from a range of pre-designed components”. Prosumption is referred to as an “important social change” influenced by both technology push and market pull; the underlying, unspoken premise seems to accept prosumption as a positive development worth fostering. The authors use their framework to elucidate the bottlenecks and channels of potential for prosumption development, as linked to current and emerging production and material technologies, cost (i.e. ‘economy‘), and production times, and to subsequently identify areas of promise for material research. Because prosumption patterns just might correlate with a localization of production and/or materials, the authors do mention the environmental benefit of lower transport emissions.

The authors see both entrepreneurs and regional development authorities as targets for their framework, a tool to support local economies in “developing countries” as well as post-industrial contexts. The point of the framework is to enable analysis/comparison of manufacturing methods that would hit an optimal combination of ‘authority’ and ‘economy’: people would get personalized stuff at a non-prohibitive cost. In the analysis examples the authors provide, additive manufacturing technologies play a prominent role in this authority/economy trade-off.

“In particular, DMLS [Direct Metal Laser-Sintering, to produce one-off, personalized watch casings in this example] makes contributions to meeting key criteria for expanding the scope of prosumption, because it better enables safe and simple production of person-specific/location-specific geometries.”

Their choice of language is difficult to understand without reading the whole article, but person-specific/location-specific geometries is what distributed production is all about. In sum, prosumption is great! We want it. The people want it too. If you want to succeed at it, get the right material technology going, this very well could be AM, and we might just see some environmental benefits too, associated with localizing production. Craft and artisan skills in production will decline because they’re too expensive, but that’s another story.

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This paper is an interesting comparison and contrast to the previous one on advanced material technologies. It’s a conceptual exploration of additive manufacturing as an “appropriate technology” (AT) for economies in the global South. Environmental sustainability benefits are not explicitly described but are embedded in descriptions of socio-economic opportunities enabled through additive manufacturing technologies – especially when offered in local, small lab and peer-to-peer operations. Moreover open source as a philosophy for design and development can allow access to and evolvement of appropriate technologies. The authors therefore focus on two open source additive technologies (two small-size 3D printers), describing their attributes and potential applications. In particular, 3D printing is appropriate for components that are

“i) small,

ii) highly customizable,

iii) expensive to manufacture/ship,

iv) difficult to transport,

v) have a large lead time,

vi) do not require precise machining and can handle small imperfections, and

vii) can be made from available, cheap, and technically viable feed stocks.”

The authors then list the functional requirements needed and barriers to overcome to truly fulfil 3D printers’ potential to be an open source appropriate technology. This paper is unique in being one of only few I’ve found to take truly peer-to-peer relationships into account as an option to design and produce solutions. Like the Diegel et al. paper above, it’s not an empirical study per se but more of a conceptual exploration.

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The following papers discuss – not necessarily additive manufacturing but – other digital manufacturing technologies common in making and fabbing.

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These authors write from the point of view of championing small furniture businesses that come from a crafts trade tradition. The (conference) paper reports on a research project that sought to strengthen the position of these skilled trade businesses. These companies have the opportunity to combine their traditional skills and offerings with digital tools and production processes, differentiating themselves from industrial players that are beginning to also offer customization services through their existing high quality craft and trade competence. The authors present a vision they call “neo-craft” and post-industrial, where they list the economic and environmental benefits of their model: locally available and customized products and services, high quality materials and processes, and designs incorporating possibilities for repair and adaptation, all of which encourage product durability. The project involved actual company partners and was therefore the first steps in realizing what would be needed for such a neo-craft vision of “technofacture”, from the perspective of regional development. If their audience is the field of mass customization, this is one of few papers in that realm that recognizes and boosts the concept of virtual products, where immaterial product designs become as important as material artefacts. Like Diegel et al. (2010) above, they also mention how the technology dictates the design and designers and/or artisans should learn how to design and craft for digital fabrication. But also like Diegel et al. (2010) the professional designer is still in control: they explicitly adopt the term “co-designer” to “express the increasing influence of the customer on the design”, meaning the measurements, materials, colours and surface design elements, but this seems to denote a limited range of design input predetermined by a design team and post-realized by a producer.

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These two (conference) papers seek to link environmental responsibility with local business development, augmented by digital technologies and personalization strategies, in their Considerate Design Project. This project emphasizes design more than regional development, by developing and testing tools for fashion designers. It, like the furniture project above, justifies its target and scope as supporting an economically and culturally significant industry – and it involved company partners – but sets its rationale more strongly in combating the negative environmental impacts of the fashion industry. The authors therefore maintain the representation of sustainability as an interlinking among the economic (jobs, company revenue, product pricing, etc.), the social (personal identity, product meanings, the designer’s ability to perform, etc.) and the environmental (pollution, emissions, waste, etc.). Personalization of products is seen as holding potential for more sustainable behaviour and production/consumption patterns, enacted through consumer input (personal preferences and/or body measurements), and enabled by body scanning and rapid prototyping technologies that are taken as the default operating environment in which designers will work.

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That’s all for this post; more and more studies seem to be coming out and I’ll summarize what I find in a future post.