Critical materials from a product design perspective

Materials and Design 65 (2015) 147–159

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Critical materials from a product design perspective David Peck ⇑, Prabhu Kandachar, Erik Tempelman Delft University of Technology, Faculty of Industrial Design Engineering, Landbergstraat 15, 2628 CE Delft, The Netherlands

a r t i c l e

i n f o

Article history: Received 27 January 2014 Accepted 17 August 2014 Available online 16 September 2014 Keywords: Critical materials Product design Scarce materials Rare earth elements Circular economy

a b s t r a c t Globally there is increasing attention towards a range of materials that have been termed critical materials. This paper will focus on a set of critical materials, mostly named as single elements, that are metals, at risk of supply constraints, have environmental implications, financially costly, price volatile, deemed economically important and are difficult to substitute as a result of their unique properties or for economic reasons. These metals are used in engineering, technology applications and product designs. A number of publications argue that product design has an important role to play in responding to critical material risks. This paper analyses and compares a selected range of 29 published definitions and descriptors of critical materials produced since the end of 1999 to June 2014. This review establishes that most definitions are developed by those outside the field of product design and the resulting definitions make it difficult for product designers, and the wider product development team, to engage in activity to address the critical materials challenge. There is a gap between the practice of product design and the current definitions. Through a structured analysis of this literature this paper develops a definition of critical materials that includes product design considerations, in order to make a first step in addressing the gap. The aim of the definition going forwards is to facilitate increased product design activity around the substitution of critical materials, including circular, closed loop, approaches, in order to contribute towards reducing critical materials supply risks. Ó 2014 Elsevier Ltd. All rights reserved.

1. Introduction The selection of materials is the starting point for any product designer [1,2]. Whilst not disagreeing with this view, Graedel has however proposed that product designers have been taught to regard materials as nothing but a means to an end, and that ‘unwise design’ choices are being made [3]. In line with this criticism some governments, most notably the UK [4] and The European Commission [5] have recently proposed that product design and innovation should play an increasingly important role in addressing concerns over critical materials. In all fields, including materials and product design, a generic definition of critical materials is important. This paper shows that the terms and definitions used for critical materials are currently variable and therefore open to misinterpretation. The paper goes on to show there is not a generic definition of critical materials for product designers and addresses this by developing a definition of critical materials that can be applied to product design. This paper uses literature review to conduct an analysis of 29 existing published definitions and descriptors of critical materials

⇑ Corresponding author. Tel.: +31 15 27 84 895. E-mail address: [email protected] (D. Peck). http://dx.doi.org/10.1016/j.matdes.2014.08.042 0261-3069/Ó 2014 Elsevier Ltd. All rights reserved.

and establishes that the majority were not written with product designers in mind, in particular regarding the practical issue of material choices for parts and sub-assemblies at the design stage. Through a structured analysis of the literature a definition of critical materials for product designers is developed.

2. Background – the emergence of critical materials The material requirements of products and technologies has become more ‘omnivorous’ [6] with a one large, global, engineering and technology company stating they use at least 70 of the first 83 elements listed in the Periodic Table of Elements [7]. This reflects a range of industries that have seen rapid technological developments over the past 30 years using an ever increasing range of materials in order to meet the performance requirements in new products. These connected activities have contributed to material supply changes that can be observed through disruptions to supply and price volatility. This picture appears to have changed in the 21st century and this can be seen in Fig. 1 [8,9]. Fig. 1 proposes a correlation between the prices of a range of commodities [9] and interest in the term critical materials shown as the numbers of hits per five-year time intervals are plotted in

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Fig. 1. IVIGI commodity price index (purple, years 1999–2001 = 100) and number of hits on ‘critical materials’ In Web of Knowledge. Vroom 2012 [10], adapted from Dobbs [9].

the graph. Thomson Reuters’ ‘Web of Knowledge’ was used to search for the following query: ‘‘TITLE = (‘‘critical material⁄’’ OR ‘‘critical metal⁄’’ OR ‘‘critical element⁄’’ OR ‘‘critical resource⁄’’)’’ The hits analysis was conducted in June 2012 [10]. Looking forwards, the material requirements of technology will increase, with the size of metals trading continuing to increase. This trend will be driven by a world of increasing population (driven by longer life expectancy), increasing wealth (in particular the rise of the ‘middle class’ in emerging economies), near term technological trends driving increased use of critical materials and the increasing complexity in the winning of new resources [3,11–13]. Fig. 2 shows the price volatility in commodity markets by looking at Metals, Fuel and food between 1980 and 2012 and highlights the ‘paradigm shift’ observed by Grantham [8]. Of note is the shift in price volatility seen since 2004/5 [14]. This trend has also occurred in relation to critical materials, however the price spike came later in 2011 and this can be seen when one looks specifically at Rare Earth Elements (REE/REO) trading as seen in Fig. 3. Fig. 3 suggests there is something different about critical materials when compared to other metals such as Iron, Aluminium and Copper. Most critical materials are metals but in terms of prices they appear to behave differently and at different times. Detailed economic analysis is beyond the scope of this paper but this example highlights the unusual economic nature of critical materials. The 2011 period of high price rises has been termed a ‘hype’ period

Fig. 3. Monthly rare earth element prices, US$ per ton rare earth oxide [15]. Note: Light REE basket is the lower line, Heavy REE basket is the upper line.

[15] but a complex range of underlying challenges, regarding supply and prices of critical materials, is on-going. It should be made clear that price changes, be they increases, decreases or volatility, are not the only metric by which a material can be determined as critical. It can be argued that a singular focus on prices could

Fig. 2. Volatility in commodity markets 1980–2012 [11].

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be misleading. In general, prices since 2011 have been dropping and many could conclude there is no risk attached to CRM’s. The details of which elements and materials constitute critical materials will be discussed in detail later in this paper. There is no agreed global list and there is significant variability geographically, both by country and/or region. If all listed elements from all countries and regions are cumulatively added together then most elements in industrial use are listed. It is proposed that this approach does not help product design define critical materials as all materials are then critical. The cumulative lists example however does demonstrate the complex and sometimes confusing nature of the topic. An overview of such a comparative table can be seen in Table 1. There are some elements that do appear frequently on the various lists. Of note are those elements that form the so called rare earth elements and platinum group metals. The Rare Earth Elements (REE, also referred to as rare earth oxides – REO’s and rare earth metals – REM’s, rare-earth elements and yttrium – REY, or even simply rare earths), are a set of seventeen chemical elements, comprising of the fifteen in the lanthanide series plus scandium and yttrium. The REE’s can be divided into light and heavy. In 2014 the European Union list REE’s following this distinction between the light and heavy rare earths as shown below [17]:  LREE = light rare earth elements (La, Ce, Pr, Nd, Sm).  HREE = heavy rare earth elements (Y, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu).  Scandium is listed on its own – neither HREE nor LREE. The Platinum Group Metals (PGM, also referred to as the PGM’s, platinoids, platidises, platinum group, platinum family or the platinum group elements – PGE’s) comprise of six metallic elements. The elements are Ru, Rh, Pd, Os, Ir and Pt. The list of products that use critical REE’s is long and wide ranging but an indicator of the applications that use REE’s can be seen in Fig. 4. This is not proposed as an exhaustive list but as an indicator in the context of rare earth elements [18]. In addition to current mainstream application technologies that use critical materials, there are a range of emerging technologies. These technologies are not ‘new’ per se but might become much more widespread and many are important in a transition to lower carbon futures. Examples are shown in Table 2 that highlight future areas of potential concern. The list is indicative of a far wider range of critical materials and emerging technologies. 2.1. Background – materials selection in product design The government report from the UK in 2012, Resource security action plan – making the most of valuable materials [4], proposes

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the extensive use of product design to address critical materials concerns. This has become an emerging theme and has gained ground over time. For this reason, it is logical to discuss how materials selection in product design is currently done. The question is then why product designers would select critical materials in the first place, if they could not instead select less-critical alternatives. Furthermore is it actually designers who make such choices, as opposed to others such as marketing specialists, supply chain/procurement staff, manufacturing engineers, logistics/supply chain experts and the financial/accounting team. This grouping of people who have an influence on the material choice during the entire product development process can be called the product development team. For new product development, the key engineering design steps involve choosing a suitable product lay-out, deciding which parts will be designed specifically for the product and which components will be bought in from stock (i.e. the ‘make or buy-decision’), and then detailing the specific parts and choosing the right stock components – with design iterations where needed [1,20]. For adapting existing products – that constitutes the majority of all product design – some of these steps can be skipped, and material choices are partially implicit in the system, barely if at all debated by designers. Also, note that products are rarely designed as standalone items but more commonly as members of product families, sharing lay-outs, bought-in components and even product-specific parts (ibid.). Implementing such ‘product platform design’ is a strategic choice that rarely involves designers only: more commonly the whole product development team are involved, with the product designer often playing a modest role. For product-specific parts, material choice follows from a process of gradual elimination, and for these parts, the designers can indeed be the main decision makers, explicitly choosing – for instance – between various grades of plastic for a product housing to determine the optimal compromise between requirements of functionality, quality and cost. This can be done both for objective material requirements [1] as for more subjective ones, such as perceived qualities and meanings [2]. Even so, their range of options is always constrained by factors and actors outside their direct circle of contacts. The question also arises about how do new materials make it into products. Ashby and Johnson in their 2010 publication, Materials and Design [1], p161, propose that new materials emerge through commercialisation via science driven development. In other words the materials scientist pushes the material into the awareness of the product designer who uses the material in a creative way [21]. This push of materials from materials lab to product appears logical. There is in most cases a symbiosis between the new material development activity and the application into products. The demands of product end users are translated into technical requirements at which point changes in materials can make a

Table 1 Critical materials – materials of interest for a range of countries. Adapted from U.S. Department of Energy, Critical Materials Strategy, December 2010 [16]. Country or region

Critical elements

Japan European Union

Ni, Mn, Co, W, Mo,V Sb, Be, Co, Ga, Ge, In, Mg, Nb, REEs, Ta, W, PGMs Updated 2014 [41]: Li, Be, Mg, Sc, Cr, Co, Ga, Ge, Y (as HREE), Nb, PGM’s, In, Sb, W, Light Rare Earth’s (LREE, not Pm), Heavy Rare Earth’s (HREE) Non elements (2014): Borates, Magnesite, Silicon metal, Coking coal, Fluorspar, Natural graphite and Phosphate rock Ag, As, Au, Be, Bi, Cd, Co, Ga, Ge, Hg, In, Li, Mo, Nb, Nd, Ni, Pb, Pd, PGMs, REEs, Re, Ru, Sb, Sc, Se, Sn, Sr, Ta, Te, Tl, V, W, Y, Zn, Zr Sb, Sn, W, Fe, Hg, Al, Zn, V, Mo, REEs As, Ti, Co, In, Mo, Mn, Ta, Ga, V, W, Li and REEs, PGMs, Si, Zr Ta, No, V, Li and REEs Al, Ag, Au, Fe, Ni, Cu, Pb, Mo Ag, Be, Bi, Co, Cr, Ga, Ge, In, Mg, Nb, Pd, PGMs, Re, REEs, Sb, Sn, Ta, W Au, Co, Cu, Ga, Ge, In, Li, Mg, Ni, Nb, Re, REEs, Se, Ta Ag, Co, Cr, Cu, Fe, Li, Mn, Nb, Ni, PGMs, REEs, Ti, Zn Ce, Co, Dy, Eu, Ga, In, La, Li, Nd, Pr, Sm, Tb, Te, Y

The Netherlands China South Korea Australia Canada Germany France Finland United States

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Fig. 4. Examples of application fields of rare earth elements [18].

Table 2 Critical materials and example emerging technologies. Adapted from [19]. Critical material

Example emerging technologies

Gallium Germanium Platinum Palladium Neodymium Indium Cobalt

Thin layer photovoltaics, WLED Fibre optic cable, IR optical technologies Fuel cells, catalysts Catalysts, seawater desalination Permanent magnets, laser technology Displays, thin layer photovoltaics Lithium-ion batteries, synthetic fuels

significant impact. In those cases there is a clear pull of new materials out of the materials lab. In any case there has to be a commercial case for the development of new materials. There is also a complexity when consideration is given to who the ‘designer’ is. There is a spectrum of product designers with at one end an engineer who designs a highly technical component and at the other end an industrial designer who is concerned more with the style and human interaction of a product. Ashby and Johnson explore this spectrum of design people by discussing technical design and industrial design [1, p. 33]. The focus for product designers, be they technical or industrial, is the performance of a material. Any consideration for the elements within a material would only typically arise if the trade name of the material gave any clues. The ‘conscious’ selection of critical materials falls to materials scientists working either in scientific research or in the R and D labs of a materials company. The technical designers (engineers) working in component companies that use critical materials will also be aware as they design such components to meet the performance requirements of upstream customers. The ‘unaware’ choice of critical materials is usually made by the sub-assembly and final product designer (technical and/or industrial) together with the rest of the product development team.

For components, the material choice is generally made implicitly. For example, the requirement for a screw to be low cost will usually lead to the selection of one made of low-carbon steel; the additional requirements for it to be corrosion-resistant and compatible with existing tightening technology could lead to a coating based on hexavalent chromium. Similarly, the requirement for an electromotor to be both powerful and small may lead to a choice for one incorporating permanent magnets made of ironneodymium (Neodymium Iron Boron – ‘‘Neo’’, NdFeB or Neodymium – Magnets). In such instances, few sub-assembly and final product designers will be aware of their choice for a critical material, i.e. neodymium. Exceptions may only arise when the element in question directly lends its name to a component, as in the case of ‘lithium-ion batteries’. Designers will only be aware if a material is critical if they are aware of what critical materials are and if the components they have selected contains them. The complexity of the situation is well demonstrated when one looks at the electronics sector. The selection of a screw is at one level of complexity but the selection of components in electronics is quite another. This is done by the electronics design engineer who has been, over recent years, driven by market demand to make designs smaller, lighter, faster, higher performance, more power efficient and robust. This has driven the selection of components that use critical materials. The electronics final product design engineer also often relies on the component designer, such as the capacitor design engineer. In the 2014 publication: Report on Critical Raw Materials for the EU [17], there is a proposal that there should be facilitated an open discussion among experts to create a network of excellence and cross-disciplinary exchange (including product designers) in order to enhance the knowledge of the most efficient use of critical materials, including their substitution. The topic of substitutability is used as part of the consideration as to which materials can be judged to be critical. The report states that the overall supply risks are considered to arise from a combination of three factors, namely:

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1. Substitutability. 2. End-of-life recycling rates. 3. High concentration of producing countries with poor governance. Note: The term ‘substitutability’ has a focus on substance for substance activity [22]. The report conducts an analysis on a range of materials and the list of candidate materials and those selected as critical (see Table 1) score poorly on the three factors. The report does acknowledge that substitution is a difficult to ‘define and measure’ concept and is subjective. This concern of poor progress on substitution is also highlighted by Graedel et al. [23]. This paper asks that given uncertainty over CRM’s in the future what is the potential for substitution of materials. They analyse the potential substitutes of 62 metals and conclude that none of the potential substitutes provide exemplary performance. This paper also indicates that the substitution activity means substance for substance replacement. The results of the two publications on substitution would suggest that it offers little for the product designer to explore, not least because there is little product user demand for materials that address CRM challenges. The results however of work by an EU funded project, CRM_Innonet, (Critical Raw Materials Innovation Network – Towards an integrated community driving innovation in the field of critical raw material substitution for the benefit of EU industry), would suggest otherwise. It depends on the scope of the word substitution. Fig. 5 shows how if the concept of substitution is broadened to include changes to processes, new technology (engineering) approaches and the introduction of a service to replace new products are all ‘substitution’ approaches. Service can include reuse, remanufacturing and recycling activities. This aligns with circular/closed loop thinking and this was highlighted in the EU Raw Materials Manifesto [24] with a call for the development of products and services that have lower impacts across their life-cycles, and that are durable, repairable and recyclable. To summarise: currently product designers are certainly not the only ones who make material choices, and when it comes to components, they usually choose the constituent materials only implicitly. They select at the level of materials, not at the level of elements. There is however a range of substitution strategies, that, if the product designer were aware of, could be used to address CRM challenges. This overview of the process of material selection by product designers, when contrasted with the critical material terms and definitions highlights a gap. The first step in filling this gap is to propose a definition of critical materials for product design.

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3. The research method This research uses literature review. In order to generate the required sample of critical materials publications for the literature review a set of literature requirements and search terms were generated and deployed. The concept of critical materials uses a wide variety of terms. For the literature review the following search keywords were used: Critical materials, materials scarcity, critical raw materials, materials scarcity, material security, rare metals supply, rare earth elements, rare earths, platinum group metals, essential substances security, criticality of materials, resource security, scarcity of minerals, priority materials, shortages of precious metals and commodities, key resources, supply security, energy-critical elements, key materials. The selected literature was published after 1999 and up to and including June 2014. The reason for this date selection was because the shift in availability and prices of critical materials started in the 21st century. The searches for the literature were conducted between 2010 and May 2014 and used Scopus and Google Scholar search engines. Peer reviewed Journal papers, academic textbooks and committee based governmental government reports were included. Only publications in English were selected. Not included in the selected literature were theses/dissertations, media articles and company reports. Such publications have however been widely read as part of the research activity. The literature was analysed using the approach of feature maps as outlined by Hart [25]. Table 2 was copied into an excel spreadsheet and columns were inserted that allowed for headings and scoring the number of times a feature was noted. No particular weighting was given to any heading. In the assessment only the following factors from the publication were assessed: 1. 2. 3. 4.

Date of publication. Main country/region where the publication originated. Words in the term used. Words in the definition given.

3.1. Results: published definitions of critical materials Table 3 shows the feature map that gives an overview of the publications selected for review. The columns ‘Term’ and ‘Definition’ were derived from the publication. It should be noted that some of the publications discuss product design but this research

Fig. 5. Substitution from CRM_Innonet [22].

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only looks for the ‘Term’ and ‘Definition’. The publications are shown in chronological order. 3.2. Results of literature analysis The graph in Fig. 6 shows the results of the literature review on the 29 publications shown in Table 2. The first 5 bars, coloured blue,1 show the country or region of main origin of the publication. The next three bars, coloured red, show the word used in the term. The final seven bars, coloured green, show the main words used in the definitions. 3.2.1. The country or region of publication The USA has the highest number of publications in the selected literature, with half of the total coming out before 2009. The EU is a union of sovereign countries and no journal papers are published from EU. The publications do not cover every year with a number of years missing. An example of this 2004–2008. There was publication in these years but where the same authors published again with no change in term or definition, the publication has not been used. There were publications in every year from 2009 onwards. The number of publications peaked in 2011. 3.2.2. The term used Out of the 29 reports and papers reviewed, 20 used the term critical (metal, mineral or material). The second most used term being scarce/scarcity (metal, mineral or material), that was observed 10 times. In 2 cases both terms were used in the same definition. The security/strategic term was used only by the UK. It should be noted that the elements, materials, metals and/or minerals being defined as either critical or scarce (or other terms) were wide and varied. So not only were the terms and definitions varied but the nature of the substance (elements, materials, metals and/or minerals) varied as well. 3.2.3. Definition The highest common factor in the definitions given is supply risk. This aspect was given in 14 of the publications. Following this is the use of high economic importance and environmental impact in the definition that was given in both cases, in 12 of the publications. Issues around demand were used 7 times. The only other issue in the definitions more widely used was around availability which came up 6 times. Issues around cost, prices, substitution and alternatives were raised in two of the publications. None of the publications used the term product or end use either in the term or definition. All of the publications do discuss the importance of product and end use to a greater or lesser degree in the body of text – but not in the term or definition. 4. Analysis 4.1. Characteristics of critical materials from a product design perspective 4.1.1. Who writes when and where The terms and definitions selected literature has mainly appeared over the past 4 years and has been dominated by 4 countries. The dates of the publications reflect the 21st century development of the critical materials story. For the first eight years of the century the publications came out of the USA. These were pio1 For interpretation of color in Fig. 6, the reader is referred to the web version of this article.

neer publications with only four of the 29 coming out up to 2009. Thereafter the number steadily rose to 2011 when nine were published. This rise corresponds to the data shown in Fig. 3 where the ‘hype’ of 2011 led to a lot of interest and publication. During this growth in publications European publications began to appear – dominated by the UK, Germany and The Netherlands. These three countries have also been highly influential on the European Commission in the writing of their various reports on CRM. 4.1.2. Critical, scarce or security – terms used The term critical materials is used twice as much as scarce materials. There is a noticeable time shift in terms, shown by the rise of the term critical materials after 2010. General and specialist English language dictionaries do not have an entry for either scarce materials or critical materials. 4.1.3. Definitions – industrial ecology It can be seen in the literature that the work of Thomas Graedel from Yale University has been very influential on the terms and definitions used for critical materials. In their work on setting out the goals and boundaries of Industrial ecology, Lifset and Graedel [45] point out that the answer to the goals of Industrial ecology is in the title of the field. Industrial – In that it has a focus on product design and manufacturing processes and ecology – in that it views firms as agents of environmental improvement. The field has a set of core elements or foci. These core elements include; a biological analogy, using a systems perspective, the role of technological change, the role of companies, dematerialization and eco-efficiency. This having been said such issues are never so straightforward and Lifset and Graedel point out that in the key theme of technological change, many look upon technological innovation as a central means of solving environmental problems. They go on to discuss the role of eco-design (or design for the environment) and the role of companies where aspects relating to critical materials can be found. They clearly define that technological innovation alone will not provide all the answers. Graedel sets a challenge to product designers in his paper ‘Defining critical materials; constraints or cornucopia?’ [3]. Here Graedel states that product designers have ‘never been taught to regard materials as anything but commodities to be employed as necessary or convenient’. He goes on to outline a number of products and associated critical materials and then asks if they are examples of ‘unwise approaches’ to design. He then outlines that there are two views on the subject of critical materials – those who feel there are limits to the availability of resources and those who feel there are not. In terms of a critical materials definition Graedel [3] refers to the US National Research Council [27] report entitled Minerals, Critical minerals and the US Economy, and uses the ‘two variable’ concept of criticality; importance in use and availability. He represents this in a graphical representation using supply risk on the x axis and impact of supply restriction on the y axis. Any elements that fall into the top right hand quadrant are deemed to be highly critical. See Fig. 7. This is a well-used approach to defining criticality over recent years. Graedel then goes on to explore Tilton’s work [11] and looks at prices and rates of use (demand/ price curves) and extends the discussion into the effect of new technology. At this point Graedel states that there is no simple answer as to whether a mineral resource is critical or not or whether its use is unsustainable. The factors in play are simply too dynamic and unpredictable to be made sense of. This brings in the time factor. The idea of a list can be nothing more than a proposed guide to what is critical and what is not at any given point in time. Add to this the differing geographical variances around the world then as Graedel puts it, ‘..these considerations have the

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D. Peck et al. / Materials and Design 65 (2015) 147–159 Table 3 Feature map showing a comparison of terms and definitions given in the literature. Title

Author

Term

Definition

Depletion and the long-run Availability of Mineral Commodities [11] 2001

Tilton JE, Report published by IIED for WBCSD, Washington, DC, USA

Mineral commodities depletion

Mineral resource availability

Mineral depletion Shortages and scarcity = opposite of availability Excess of demand over supply Declining availability On Borrowed Time? Assessing the Threat of Mineral Depletion [26] 2003

Tilton JE, RFF Press, Washington, DC, USA

Mineral depletion

Mineral resource availability Mineral depletion Shortages and scarcity = opposite of availability Excess of demand over supply Declining availability

Scarcity and Growth in the New Millennium: Summary [12] 2004

R. David Simpson, Michael A. Toman, Robert U. Ayres Discussion Paper 04-01 Resources for the Future, USA

Minerals, Critical Minerals, and the U.S. Economy [27] 2008

Eggert, R.G., et al., Minerals, Critical Minerals, and the U.S. Economy, National Research Council, USA

Scarcity

Resource limits to growth

New scarcity Critical minerals

The two dimensions of criticality are:

Critical materials

1. Importance in use 2. Availability

Methodology of Metal Criticality Determination [3] 2009

Thomas E. Graedel, et al., Yale University, USA

Metal criticality

A critical metal involves three dimensions: 1. Supply risk 2. Environmental implications 3. Vulnerability to supply restriction

Material Scarcity [28] 2009

Critical Metals for Future Sustainable Technologies and Their Recycling Potential [29] 2009

Wouters H and Bol D, Materials innovation institute (M2i); The Netherlands

Buchert M et al., UNEP, UNU, Öko-Institut e.V., Germany

Material scarcity; Critical elements Critical materials

Supply of the material versus its demand

Critical metals

A metal with:

Balance is affected by socio-economic factors Critical = quantities used & change in supply, has an impact on current lives, and that resources will expire in the next two to five decades

1. High demand growth 2. High supply risks 3. Recycling restrictions Critical raw materials for the EU [19] 2010

Ad hoc working group under the authority of the European Commission, EU

Critical raw materials

1. High access risks, i.e. high supply risks or high environmental risks 2. High economic importance

The German Government – raw materials strategy [30] 2010

Federal Ministry of Economics and Technology (BMWI), Germany

Distorted raw materials supply, security materials

Uses EU def:

1. High access risks, i.e. high supply risks or high environmental risks 2. High economic importance Critical Materials Strategy 2010 [16]

Bauer D, et al., Department of Energy, USA Revised and updated 2011

Key materials

A material with:

Critical materials

1. High importance to clean energy technologies 2. High supply risk

Global Resource Depletion – Managed Austerity and The Elements of Hope [31] 2010

Diederen A, Eurborn Academic Publishers, Delft, The Netherlands

Scarcity of metals

Energy scarcity = materials scarcity, peak metals curve

Critical materials in the Dutch Economy – Preliminary Results [32] 2010

Statistics Netherlands, The Hague, The Netherlands

Critical materials

1. High access risks, i.e. high supply risks or high environmental risks 2. High economic importance, EU Definition graph shown

Material Efficiency: A white paper [13] 2011

Allwood J et al., Journal of Resources, Conservation and Recycling, United Kingdom

Scarce materials

1. High demand materials 2. Scarce selected materials 3. Materials that affect security 4. Climate change impact materials (continued on next page)

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Table 3 (continued) Title

Author

Term

Definition

Strategically important metals [33] 2011

Science and Technology Committee – House of Commons, United Kingdom

Strategic metals

A metal that may be of importance to any user within the United Kingdom – used chemical innovation KTN and EU lists

Scarcity in a sea of plenty? Global resource scarcities and policies in the European Union and the Netherlands [34] 2011.

Netherlands Environmental Assessment Agency (PBL), NL Government The Netherlands

Resource scarcity

Minerals that have:

1. Physical scarcity; demand and applications 2. Political scarcity; concentration leading to abuse Critical Metals in Strategic Energy Technologies, Assessing Rare Metals as Supply-Chain Bottlenecks in Low-Carbon Energy Technologies [35] 2011

Raw Materials Critical to the Scottish Economy [36] 2011

Criticality of Non-Fuel Minerals: A Review of Major Approaches and Analyses [37] 2011

Moss et al., Joint Research Centre, European Commission Petten, The Netherlands, Oakdene Hollins Ltd, United Kingdom, and The Hague Centre for Strategic Studies, The Netherlands

Scotland & Northern Ireland Forum for Environmental Research, Scotland, United Kingdom

Erdmann L & Graedel T E, Institute for Futures Studies and Technology Assessment IZT, Germany & Yale University, USA

Significant metals

A material with:

Supply-chain bottlenecks Critical metals

1. A relatively large share of the total future supply that will be consumed by a strategic energy technology 2. High risk of supply-chain bottlenecks

Resource risks

Scores high on the following criteria:

Critical resources Key resources

1. Combined consumption/production and scarcity/availability 2. Availability of alternatives 3. Supply distribution 4. Supply domination 5. Extent of geopolitical influences 6. Press coverage 7. Price fluctuation

Material criticality

Material criticality captures two aspects:

1. Supply risks 2. Vulnerability of a system to a potential supply disruption Critical Materials for Sustainable Energy Applications [38] 2011

Fromer N et al., Resnick Institute, USA

Critical materials

A material with: 1. High importance to clean energy economy, i.e. it has one or more properties that appear to be physically essential for the performance of the system 2. Some uncertainty or risk in the supply

Energy Critical Elements: Securing Materials for Emerging Technologies [39] 2011

Jaffe R et al., American Physical Society & Materials Research Society, USA

Energy critical elements

The term ‘energy-critical element’ is used to describe a class of chemical elements that currently appears critical to one or more new energy-related technologies. More specifically: 1. Elements that have not been widely extracted, traded, or utilised in the past 2. Elements that could significantly inhibit large-scale deployment of the new energyrelated technologies

Study on Rare Earths and Their Recycling, Final Report for The Greens/EFA Group in the European Parliament [18] 2011

Schüler D et al., Öko-Institut e.V., Darmstadt, Germany

Critical metals

A metal with:

1. High demand growth 2. High supply risks 3. Recycling restrictions Methodology of Metal Criticality Determination [40] 2011

Thomas E. Graedel, et al., Yale University, USA

Metal criticality

The degree of criticality of the metals of the periodic table: 1. Supply risk 2. Environmental implications 3. Vulnerability to supply restriction

Material Efficiency: An economic perspective [41] 2012

Söderholm P and Tilton JE, Journal of Resources, Conservation and Recycling, USA

Material scarcity

1. Material availability 2. Short-term scarcity 3. Long term resource depletion

Resource Security Action Plan: Making the most of valuable materials [4] 2012

Department for Environment, Food and Rural Affairs, United Kingdom

Resource security Critical resources Resource risks

Risk to business – multiple and varied factors

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D. Peck et al. / Materials and Design 65 (2015) 147–159 Table 3 (continued) Title

Author

Term

Definition

Critical materials Materials and the Environment – ecoinformed materials choice, 2nd ed [42] 2012

Michael F. Ashby Butterworth-Heinemann, United Kingdom

Resource criticality

Material sustainability – flows of energy, biomass and materials

Scarcity Strategic materials Materialsenergy-carbon triangle Critical materials and The Netherlands – a view from the industrial – technological sector [43] 2012

Bol and Bastein, M2i and TNO. Translated from Dutch by: Moerland-Masic I and Peck D, The Netherlands

Critical materials

The omnivorous diet of modern technology [6] 2013

Greenfield A and Graedel TE, Resources, Conservation and Recycling 74 2013 1–7 [4] USA

Elemental scarcity, metal criticality, material constraint

Material efficiency: Rare and critical metals [44] 2013

Ayres RU, Talens Peiró L. Phil Trans R Soc A 371: 20110563. USA

Critical materials

Metals and industrial minerals, crucial to modern society, decreasing as a result of increasing demand combined with a range of geopolitical complications Materials and elements: Biophysical, political, increasing population, increasing wealth, declining ore deposits, minerals widely dispersed Metals that are:

1. 2. 3. 4. 5. Report on Critical Raw Materials for the EU [17] 2014

Report of the Ad hoc Working Group on defining critical raw materials, Mattia Pellegrini (WG chair), European Commission, DG Enterprise and Industry, May 2014

Critical materials

Geologically scarce Subject to potential supply constraints Costly Economically important Difficult to substitute

Critical when risks of supply shortage and their impacts on the economy are higher compared with most of the other raw materials Assessment components:  Economic importance  Supply risk and environmental country risk Features:  Pragmatic approach  Indicators-based  Dynamic concept  Primary and secondary raw materials

25 20 15 10 5 0

Fig. 6. Graph showing the results of the literature review.

potential to limit the supplies of certain materials, though at different temporal and spatial scales’. Graedel adopts a precautionary stance and proposes an approach of more thoughtful and careful use is the best way forwards. Graedel et al. have developed a further cross cutting analysis in defining metals criticality shown on Fig. 8. The supply risk axis remains but is complimented by two vectors showing vulnerability to supply restriction and environmental implications [23]. This development does indeed compliment the findings in Fig. 6 in this paper.

As well as the peer reviewed journal papers, committee based governmental reports are included and they all appear to develop the Graedel approach. The UK issued a materials scarcity report in 2007 [46] that used the ‘two variable’ concept of criticality and generated ‘lists’ of materials and likely applications. The US National Research Council [27] report entitled Minerals, Critical minerals and the US Economy, followed and again uses the ‘two variable’ concept of criticality; importance in use and availability. Again risks rating and lists were deployed. This was followed in 2010 by the EU report on critical materials [19] that used the same

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Fig. 7. The criticality matrix allows an evaluation of the ‘‘criticality’’ of a given mineral. Material A is more critical than material B [3,27].

approach. Numerous reports from the UK, Netherlands, Germany, Japan, China and many other countries have arrived at similar results. This approach allows for a list of most critical materials to be generated as already shown in Table 1. They are usually listed as elements and most are metals of one type or another. This suggests that materials criticality is both geographic and product dependent. The detailed explanations for the wide variation in the materials in these lists is beyond the scope of this paper. Table 1 does however highlight the geographical problem with lists. There are other problems with the lists approach. The lists sometimes mix up elements and materials – a distinction that has the potential to confuse some product designers. The lists are also snap-shots in time and are out of date very quickly.

4.1.4. Product design The subject of critical materials and material efficiency (sometimes referred to as resource efficiency) is addressed by Allwood et al. [13] a paper entitled material efficiency: A white paper. Allwood et al. outline material efficiency as providing the service users want from a material with less material and less processing. This in turn means less energy. Their paper goes on to discuss critical materials more widely by referring to running out of materials or future ore shortages. Allwood et al. do look at aspects of material criticality from the perspective of product designers by proposing the design of products for longer life, more intense use, repair and re-sale. This position does not clearly appear as a critical materials definition (and therefore is not included in the selected literature), but their work was not aimed at defining critical materials. The paper discusses at length the decisions points to be made for each of the product design strategies. The Allwood et al. work compliments the detailed discussion on materials efficiency, critical materials and product design in the Ashby book Materials and the Environment [43]. In that text Ashby uses the term Strategic (critical) materials. He defines strategic or critical ‘..if their supply is concentrated In one country or could be restricted by a few corporate interests, and because they are important economically or for national security’. If any of the selected literature does define critical materials for the product designer then it is the Ashby–Allwood school where critical materials – product design thinking has been carefully developed in Cambridge, UK. This approach has also been developed by Köhler et al. [47]. As stated in the types of literature sought company reports and documents were excluded from the literature review. Such company reports and other open access documents have not however been ignored. One document of note has been published by Granta Design in Cambridge, UK. Entitled ‘Background to Critical Materials’ [48]. This report is worthy of note because it contains a critical material definition with product design in mind. It should be noted that Ashby is a co-founder of the company. The structure of this definition has been used in the formulation of the definition given later in this paper. There is consistently a theme that appears on a regular basis – especially in the wider media, that of ‘how long until we run out?’. This question is a good exemplar of the complexity of the topic

Fig. 8. The Yale analytical framework for determining metal criticality at the global level [23], with the metrics described in detail in [41].

D. Peck et al. / Materials and Design 65 (2015) 147–159

of critical materials that possibly leads product designers to misunderstandings, uncertainty and then dismissal of the topic. Clearly with a finite material there does exist a point in time (if the material were to be constantly consumed and dispersed beyond recovery) when it would ‘run out’. With critical materials the ‘running out’ figures widely given are based on a ‘fixed stock’ paradigm. If the known reserve is x tonnes and the consumption is y tonnes per year then we have z years left. The problem is the reserve and consumption figures change all the time. Themes such as price volatility, stockpiling, hedging, substitute materials, new products that use new materials/technologies (and old products in being withdrawn), changing mining and processing technologies, new discoveries, old mines becoming uneconomic, recycling, reusing, remanufacturing, conflict, geo-politics, trade disputes, human rights, emerging economies growth, global economic growth, demographic shifts, etc. all add to make the analysis extremely complex and uncertain. This situation could reinforce the Graedel–Ashby–Allwood position of a precautionary stance, proposing an approach of more thoughtful and careful use being the best way forwards. This precautionary position is, however, not one solely based on ‘pessimism’. There is a lot of ‘optimism’ in all parts of the value chain, not least in the product design opportunity arena. Whilst there is little mention of product design in the definitions there are a considerable number of instances of product design contributing to a solution. This work has not had a focus on critical materials but points the way to useful strategies [49,50]. The literature presents a range of product design solution opportunities, for example a move to a circular economy – but these fall outside the scope of this paper. Table 4 demonstrates gaps regarding applicability of the critical materials definitions to product design. There is a further gap that revolves around the discussion of elements when the product designer uses materials. It is around the function of a technology and not the elements within it. The critical materials literature has mainly been developed by industrial ecologists, economists, material scientists, mining engineers, international relations experts, etc. and has seen far less contribution by product designers. 4.2. A new definition of critical materials for product design The review of the literature establishes that critical materials are not well defined for product designers, in particular to develop

a range of substitution strategies. In addition there is no global consensus on a definition and accompanying list of what are critical materials. This becomes even more complex once one looks forwards in time. From the analysis of the literature and the gaps identified in Table 4 a new definition for critical materials for product design has been developed. To do this the following key points were derived (please note references for these points can be found in the literature list and the analysis in Section 4 above): Critical materials: – Are usually ‘invisible’ and are alloyed into other materials. They are normally named as elements and lists of which elements are affected are variable and regularly change. Lists of critical materials can change in different geographical contexts and different organisational contexts. The elements (critical and non-critical) are usually combined together to form alloys that deliver the required performance. – Allow unique performance to be attained from materials that in turn affect both form and function of a product. Critical materials play an important role in parts and components making them, for example, lighter, stronger, smaller, higher performance and have delivered radical new technology innovations that the product user values. – Are subject to supply challenges. This can include price volatility, price rise (and drops), quality changes, supply delays (and floods) and potentially – supply stops. Demand for critical materials can be high. The supply and prices of critical materials are subject to a complex and dynamic range of forces including both political and geopolitical. – Cannot easily be substituted (substance for substance) with a less critical alternative, to achieve the physical or chemical properties that are needed, because of the cost and time required. A narrow definition of substitution (substance for substance) is normally used. The substitution of critical materials, reduction and recycling of critical material content, is technically, scientifically and economically challenging. – There are a range of substitution options to compliment substance for substance substitution. These are: changes to processes (process for process), new technology (engineering) approaches (new technology for substance) and the introduction of a service to replace new products

Table 4 Comparison of critical materials literature with product design practice. Critical material terms and definitions in literature

Activity in product design

Critical material Scarce material Supply risk

Term not widely used Term not widely used Not widely used in conjunction with critical materials. Risk assessed for the ‘make or buydecision’ Not widely used in conjunction with critical materials. Focus on strategic choice ‘economics’ concerning the company Not widely used in conjunction with critical materials Not widely used in conjunction with critical materials. Focus on strategic choice involving, market demand, procurement risks, manufacturing capacity and logistics lead times Not widely used in conjunction with critical materials. Focus on procurement risks – lack of availability, and logistics lead times

High economic importance Environmental impact Demand Availability

Issues raised in product design not widely addressed in critical materials literature Performance and function Costly – raised in one definition Substitution is a widely used critical material solution in the literature but not in the definition, except for one publication

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Not widely used in conjunction with critical materials. This is an important topic in product design. Product designers not aware of the role of critical materials in product Not widely used in conjunction with critical materials. Costs of materials – widely used – important consideration in product design. Costs of critical materials not widely known Not widely used in conjunction with critical materials. Substance for substance material substitution leading to a product change more generally used

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(service for product). Service for product includes reuse, remanufacturing and recycling activities. This aligns with circular/closed loop thinking. – As with all metals, extraction, processing and recycling of critical materials carry a risk of environmental impact, but they can also provide opportunities to significantly reduce environmental impacts during product use and critical material use should not be avoided. From these points the following term and generic definition has been developed:  Term: critical Material (noun).  Definition for product design, 2014. A critical material concerns a range of metal material resources that are selected in the product design process for a wide range of products. They are usually ‘invisible’ to the product designer, normally named as elements and provide a unique performance that the product user highly values. Critical materials can be subject to supply challenges, often cannot be easily replaced with less critical substitutes and can be challenging to recycle. Critical materials can be substituted using a range of approaches including using circular/closed loop thinking. Critical Materials can provide opportunities to significantly reduce environmental impacts during product use and critical material use should not be avoided. To complement the definition an example list from Europe of what are critical materials is [41]:  Elements: Li, Be, Mg, Sc, Cr, Co, Ga, Ge, Nb, Platinum Group Metals (RU, Rh, Pd, Os, Ir, Pt), In, Sb, W, Light Rare Earth’s (LREE, – La, Ce, Pr, Nd, Sm), and Heavy Rare Earth’s (HREE – Y, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu).  Non elements: Borates, Magnesite, Silicon metal, Coking coal, Fluorspar, Natural graphite and Phosphate rock. 5. Conclusions This paper has highlighted that published definitions around critical materials are complex and for many when taken together confusing. Concerns over price volatility and supply are relatively recent and given the complexity of the subject it is not surprising that knowledge and understanding of product designers needs further development. The subject demands multi-disciplinary action across the entire value chain and this approach is also not yet widespread. Critical materials is a subject that has generated some to take adversarial positions around ‘pessimists’ versus ‘optimists’. It can be argued that this has distracted people and lost valuable time. These positions are now however now beginning to merge as the limits and opportunities of both views are becoming better understood. Given the importance of the topic it is perhaps surprising the limited number of key publications on the topic from the product design community. Evidence of this can be seen in the limited number of European governments who have a clear critical materials policy linked to product design and development. This is despite the European Commission taking a lead on the subject for a number of years now. The definitions show a lack of coherence with some publications demonstrating a lack of co-ordinated building on the topic. It is clear that the majority of the definitions were not written to facilitate product designers to take action. Product designers are, however, being increasingly ‘tasked’ to help to ‘fix’ the challenge, particularly through substitution and design for recycling activity. The best work seeking to engage with product design comes from

the Ashby–Allwood ‘school’ in Cambridge, UK. Like all partner engagements, however, it takes both sides to want to come together and as can be seen from the literature, there is little engagement from product designers on the subject of critical materials and product design. There are a range of accepted approaches towards materials in product design that excludes critical materials thinking. This paper has put forward a definition that includes the key points raised in the literature. The proposal of an expanded thinking around substitution, including circular/closed loop thinking is welcome. It is hoped that others will challenge the definition given in this paper and work to develop it further as the challenges and opportunities, that critical materials presents to product design, unfolds.

5.1. Recommendations for further work a. Alignment of critical material definitions around a shortened ‘most critical’ list to help focus product design activity. b. Defining more clearly for product designers the wide range of factors that drive criticality. c. Enhancing transparency about material use across the whole value chain to develop data for the product design activity. d. Development of the substitution framework shown in this paper to support the product design activity. In particular circular/closed loop approaches. e. Revisit past product design responses to material constraints and derive useful knowledge for use today. f. Develop the interaction between product design and policy makers to find optimal solutions across the whole value chain.

Acknowledgments This research has been supported with funding by a European Union Seventh Framework Programme project entitled CRM_Innonet, Critical Raw Materials Innovation Network – Towards an integrated community driving innovation in the field of critical raw material substitution for the benefit of EU industry. The Grant agreement number is 319024. Further support was provided by United Nations University – Solving the E-Waste Problem (StEP), The Circle Economy, Netherlands and The Ellen MacArthur Foundation for a Circular Economy.

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