Designers need to be materialistic. Not in the sense of being superficially obsessed with material things, but in the literal sense of being focused on materials themselves, the very substance and content of the products they design.

In the course of new product development, the selection of materials is one of the most daunting and intimidating aspects of the project. In some cases, it may turn out to be the single most important decision made. Using the right stuff can make a product. Using the wrong stuff can break it.

Function, aesthetics, and costs have traditionally been the factors used to determine which material to use, but new factors have emerged that must be taken into account. Environmental issues are front and center when it comes to new product development with local and international regulations as well as marketplace expectations playing a role in choosing a material. Materials must be chosen with an eye toward the product’s overall appeal to today’s market, and the other eye focused on the product’s lifecycle.

Aerogel by Airglass AB of Sweden consists of 99.8 percent air, making it the lightest solid material ever produced. Source: ASM

The paradigm has changed, says Andrew Dent, vice president, Library and Materials Research, for Material ConneXion, a New York-based materials consulting firm. In the past, the assumption was that design of the form was everything and after that, materials would be found that satisfy the design. Today, Dent says that attitude has changed. Now, designers are using information about materials up front in the development process to actually influence the design.

And, there is a vast amount of information to be found. Literally, thousands of materials are available to the designer and new materials are continuously being unveiled. Material ConneXion operates a material library that is constantly adding new products to its database (www.materialconnexion.com). The library, which is divided into seven material categories and a process category, adds 500 to 600 new materials a year. In August 2008 alone, 49 new materials were added including an injection-moldable, high-performance resin made from corn and milk resin products; a clear, thermoplastic urethane formed into a lace-like web of single filament polymer; and ready-to-laminate printed LED films that are designed for lamination between glass, PMMA, acrylics, and polycarbonates.

And, that is just one materials database. Several others are available for designers to use. The newest is a website from Cleveland-based ASM International. Since 1913, ASM has been a resource for materials information, primarily metals, geared for engineers and scientists. It is now branching out to provide information on a whole range of materials. ASM has started a new web site called /Mtrl – presenting Material about Materials (www.mtrl.com). To build the community, ASM held interviews and focus groups with designers to understand their needs. “We found that the design field truly represents a blending of art and engineering, as many designers have mechanical or electrical engineering backgrounds, while others have backgrounds in art or industrial design,” says Laura Marshall, director, business initiatives for ASM International. The site details materials with technical data for the engineers, but also presents information in a language that industrial designers can understand, she says.

This material from UK based d3o is soft and flexible, but the molecular structure has been engineered to stiffen on impact and absorb energy. Source: ASM

For instance, the site includes a material called Air glass and describes it as “an aerogel that consists of 99.8 percent air, making it the lightest solid material ever produced. It is also one of the best heat-resistant materials and a good insulator.” Designers have the option to drill deeper into the site, looking at many materials both from a narrative point of view as well as looking at technical specifications.

But, sometimes knowledge of a material’s properties is not enough. For instance, will a material chosen violate an environmental regulation? Will the material’s use cause unforeseen problems and ethical dilemmas? Companies including Sony and Sony Ericsson faced such issues when one of the components they use in their products was linked to a brutal conflict and slave labor in the Republic of Congo. The material in question is the unrefined metallic ore, coltan, which is processed into a powder called tantalum. Tantalum is used in electric capacitors that are extensively used in cell phones, computers, game consoles, and other compact, high-reliability electronics. Sony has had to change how they get the material, making sure that they obtain the material from a variety of sources and locations. And, Sony Ericsson, a 50/50 joint venture of Sony and Ericsson, now dictate that its suppliers cannot use illegally mined tantalum from the Democratic Republic of the Congo and the surrounding area.

Keeping track of all the possible factors that designers might need to consider is not an easy chore. Granta Design, Cambridge, U.K., offers software that helps guide the choice of appropriate materials, based on the functional requirements of the design, the overall design objective – such as minimizing cost or weight – and any additional specific constraints. The software ensures all candidate materials and manufacturing processes are considered in a systematic and un-biased way, and provides tools to assist in assessing the trade-offs between design requirements that are often in conflict. Granta has established a number of customer consortia to guide the development of its software. Their first such venture, the Material Data Management Consortium (see www.mdmc.net) was launched over 6 years ago, and has had a key role in the definition of best practice management and use of materials information. Now, the company is working with U.K.’s National Physical Laboratory to establish the Environmental Materials Information Technology (EMIT) consortium to provide solutions for selection of materials in the context of their environmental impact, and associated national and international legislation.

Chart shows tensile strength v. density for 3,000 engineering materials. Each small bubble represents a materials and the larger envelopes enclose families of materials. Source: Granta Design

Granta also offers software to help companies develop and implement material strategies across their enterprise. This is particularly relevant for companies that must manage many different locations and local procurement practices, says Arthur Fairfull, director of Granta’s Materials Strategy initiative. In this case, the software can help them take a centralized strategic approach to materials selection and acquisition. The resulting strategies, distributed to designers throughout the company and accessed through a Web browser, can enable significant rationalization of the number of different materials and materials suppliers used by the company.

The approach is based on a methodology created by Mike Ashby, a world-renowned professor of materials engineering at Cambridge University, and founder of Granta Design. It enables material decisions to be made based on broad ranges of information, and includes intuitive graphical tools to illustrate the options. Ashby charts, as they are sometimes called, can quickly highlight the subset of candidate materials on which to focus. If, for example a designer needed to explore the trade-off between strength and insulation properties, the software can create a graphic displaying tensile strength vs. thermal conductivity for the 3,500 engineering materials in its “materials universe” database. At a more sophisticated level, prices for a given functionality – such as for a plate in bending, or a tube in torsion – can be generated for each material, displaying what the company calls the “cost per unit of function.” Similarly, if environmental impact is paramount, the software can generate indices combining the functional capabilities of the candidate materials with, for example, the carbon dioxide emissions resulting from their primary manufacturing processes. Designers can therefore explore the trade-offs between cost, emissions, and the required engineering properties in a systematic and consistent way.

This can help designers resolve the great ongoing debate between choosing metal or plastic for a given part. Costs run the gamut in both, from low-cost polyolefins to high-priced engineering resins in plastics, and in metals from low-cost carbon steel to higher priced magnesium. Plastic parts incur high upfront tooling costs, but can then be cheaply cranked out in high volume. The ability to mold in multiple functional features on plastic parts can often result in parts count reduction.

Materials prices for a panel of specified stiffness illustrates how price and materials property data can be combined to study “cost per unit of function.” Source: Granta Design

Metals are typically stronger than plastics, which allow thinner dimensions and reduction of material usage. In the case of housings, they also offer inherent shielding properties and thermal dissipation characteristics. On the other hand, depending on the metal and the application, the metal parts often require secondary operations such as machining and/or finishing.

The ground beneath the argument is ever shifting as new materials and processes constantly alter the calculations. New additives and custom compounds take plastics to previously unobtainable heights. New alloys, coatings, and overmolding processes also cast a new sheen on metals.

Certain metals can be processed as easily as plastics such as Liquidmetal from Liquidmetal Technologies, Lake Forest, Calif. The material is considered to be twice as strong as titanium, won’t rust, and can be cast as easily as plastic. Other technologies allow less expensive metals to be used in places where higher-cost materials once were needed. For instance, a surface treatment called Keronite Plasma Electrolytic Oxidation can make aluminum harder and more wear resistant than the more expensive, and heavier, steel. Keronite used on AZ91D magnesium alloy can make the material harder and more corrosion resistant. Within the past few years, molders have learned how to overmold elastomers onto zinc and magnesium die-cast parts, providing yet another option for designers of portable electronics.

Samsung's new bioplastic phone, model F268, is made from material extracted from corn.

Beyond properties and processes, perception also plays a role, as materials become a way for companies to brand their product. Apple’s new iMac computer features an all-aluminum housing, which helps the product stand out from its competitors using plastic.

Aluminum may even help from a functional standpoint, providing inherent shielding and improved thermal dynamics. But, Chris Lefteri a design consultant and author based in the U.K., says that today the specifying materials are not just about its physical properties, but also how the materials can help strengthen the brand. He says Apple’s use of aluminum ties in with the softer side of material selection, which he says is not about mechanical properties, drop tests, or other hard data sets, but about how a product makes the consumer feel.

This increased awareness of both the “hard” and “soft” side of design has changed and blurred the lines between industrial designers and design engineers. In the past, design engineers focused on the internal function of a device, and then handed it off to the industrial designers to create an attractive form to envelop it. (With both leaving it to a manufacturing engineer to figure out how to make it.) But today, such roles are less constrained and more overlapping. Chris Cavello, president, Mixer Group, Austin, Texas, says that an ordinary engineer just worries about making the thing work, and an ordinary designer just worries about making it pretty, but a good engineer is sensitive to aesthetics and a good designer understands how things work.

Liquidmetal alloys from Liquidmetal Technologies are twice as strong as titanium, won’t rust and can be processed as easily as plastic.a

More and more often, firms are employing designers and engineers that are familiar with each other’s disciplines, says Hayes Urban, senior designer for Design Edge, also of Austin. There is a definite trend toward professionals with multiple skills, he says. This expanded knowledge set is important in the evolving dynamic between designers and engineers, whether they be in-house designers and engineers or as part of a custom/design firm relationship. In every case, industrial designers and engineers must hash out the form and the function, what works best, what looks best, and how this can be done at cost.

This balancing act between aesthetics, costs, and function requires constant adjustment, as new options enter the field of play. The designer might want a particular color or special effect in a polymer, for instance, but not be able to get that look because the pigments needed to achieve the look may alter the polymer’s mechanical properties. Or, the designer might want a particular functionality, but they may not be able to obtain those goals within the cost structure. Design is about managing the varying compromises or the interactions of these decisions with other goals, says Cavello, that is the core of the design process.

Lefteri says that it is critical that in addition to material properties, designers should learn about the manufacturing processes that turn raw materials into finished products. Like the materials themselves, new ways to produce products faster and cheaper are constantly under development. Examples can be found in new injection molding methods that use gas and/or water to more quickly produce parts. “You can’t separate materials from the method of converting them into product,” he says.

Enlarge this picture At each stage of a product’s lifecycle, resources and energy are used and unwanted emissions and waste are created. Much of this impact is due to materials and their processing. The EMIT Consortium will focus on reducing this impact. Source: Granta Design

Volume of production is also critical, Lefteri says. Glass, as an example, is relatively inexpensive, but when a glass product is hand-blown costs can skyrocket, he says. A small part with low profit margins can only be economically justified if it can be made quickly and in volume. In this scenario, faster cycle times are needed and the manufacturing process would be more akin to an injection molded plastic resin. In another scenario, if durability was pivotal, a metal casting or stamping might be the best answer.

While some applications, such as in the medical device industry, are less concerned about cost considerations – functionality being paramount – for many applications, cost is the major factor. Most consumer product manufacturers have a good, better, and best product line that hits the low, middle and high price points. Product designers must balance design objectives with cost targets.

Shifting material costs can force a rethinking of design. Manufacturers that use stainless steel, for instance, have been hurt by a dramatic increase in the price of nickel, which is a prime ingredient in stainless steel. So, designers are exploring cheaper alternatives to achieve a stainless steel look such as using films and coatings to achieve a faux stainless steel look. Manufacturers desiring the traditional chrome look are also looking at new alternatives as the cost of electroplated chrome has escalated and environmental regulations have made the use of electroplated chrome unwelcome in European Union countries as a result of the EU Restriction of Hazardous Substances regulations.

Since July, 2006, the ROHS directive has restricted the amount of lead, mercury, cadmium, polybrominated biphynyls, polybrominated-diphenyl ether, and hexavalent chromium. Designers whose products are to be sold in Europe had to rework the materials that they used to comply with RoHS. Restrictions are being discussed in other areas as well. Published reports say that the EU is reviewing another 46 substances to see if they need to be limited in products. In addition, China is reportedly working on similar restrictions. In the U.S., individual states including Maine and Massachusetts have considered similar substance restrictions that would even surpass that of RoHS.

Designers also must take into account the various technical regulations that force them to use alternate materials or use different processes. For instance, the European Union’s EMC Directive puts limits on EMI emissions. Products might have to be shielded, or if the offending source of EMI is on a circuit board, the board can be shielded without having to shield the overall housing.

Here, too, tradeoffs may need to be made. A simple solution is to use a metal barrier as it provides inherent shielding, but this can add weight and cost. Plastics, unless augmented, have little in the way of inherent shielding. Embedding raw polymer with conductive particles such as carbon, metallic fibers or other conductive fibers, can turn a molded plastic part into a shield.

Lefteri says that satisfying regulatory issues or alleviating environmental concerns may require more than just specifying low-energy materials or a biodegradable plastic, he says. At a more sophisticated level, a level he says we are entering now, the choice might be choosing a material with different mechanical properties. For example, the bottled water industry produces billions of plastic bottles every year with recyclable plastics, but perhaps a better choice might be to use a more expensive, ultra stiff plastic that uses less material.

A product’s impact on the environment should be considered throughout its life cycle, or from “Cradle to cradle,” according to Steven Bolton, manager of business development with MBDC (McDonough Braungart Design Chemistry), a Charlottesville, Va., design firm. The company recently entered into an agreement with Material ConneXion and the Environmental Protection Enforcement Agency, an environmental group, to promote the cradle-to-cradle idea. The concept considers the complete lifecycle of the material in a product, and the product’s impact on human and environmental health. Bolton adds that the concept of sustainable design recasts typical measures of material and product quality — cost, performance and aesthetics — to include and apply new objectives, such as ecological intelligence and social responsibility. The cradle-to-cradle framework moves beyond the traditional goal of reducing the negative impacts of commerce, he says, to increasing a product’s positive impacts.

End of life issues may impact one of the most talked about materials on the market – bioplastics. While not formally defined, the term bioplastics is typically used to describe plastics not made from petroleum. Instead they are often made from plants or even waste products. (One company even makes bioplastics out of pig urine and feces.) While bioplastics are growing in popularity, especially in Asia, their uses might be limited because of recycling issues. They cannot be placed into traditional recycling streams because they can’t be mixed with petroleum-based plastics in recycling. Mixing the two can contaminate the recycling stream and make the whole unusable for future use.

Even considering that, many designers feel that bioplastics will play an increasing role in future material choices, as will more capable materials. Smart materials, such as shape memory effect metals and polymers that change properties as a result of external forces and stimuli, are expected to grow in use, Lefteri says. Nanotechnology, too, is expected to play a major force in the development of new materials. One product that recently entered the market is a material called NanoTitanium, which uses nano materials to create super strong metals. The material has been developed by scientists at Los Alamos National Laboratory and is being marketed by New York-based Manhattan Scientifics.

Of course, not all of the “new” materials are really new. Bamboo has found a home in some consumer electronic applications (See sidebar on page 38.), but it has been used as a building material throughout history. While most experts feel that bamboo is a niche material, it is an example of how even old materials can be used in new ways. Since bio-based materials are renewable, they can provide an option when traditional non-renewable materials become scarce or high-priced.

The onslaught of new materials, shifting consumer attitudes, rising costs, and a more restrictive regulatory environment all ensure that the world of materials will remain a volatile one and designers will have to follow new developments as attentively as they follow the news.

For more information, email:
ASM International, rego.giovanetti@asminternational.org
Chris Lefteri Design, info@chrislefteri.com
Design Edge, info@designedge.com
Granta Design, Stephen.Warde@grantadesign.com
MBDC (McDonough Braungart Design Chemistry), steve.bolton@MBDC.com
Material ConneXion, access@materialconnexion.com
Mixer Group, Chris@mixergroup.com
SKD (Stuart Karten Design), anne@kartendesign.com

Sidebar: Electronics Seeing Green

The SimpleTech [re]drive from Fabrik was designed by SKD Designs. It features a bamboo top and aluminum sides that act as a heat sink.

The marketplace is beginning to overflow with computers and computer accessories that have been built with environmentally friendly materials and processes.

For example, Dell recently introduced a computer called the Studio Hybrid. The Energy Star 4.0 compliant computer comes with a bamboo case, is about 80 percent smaller than a typical desktop minitower, and uses 70 percent less energy. In addition, some of the materials used in the computer were made with recycled plastics.

Dell’s Studio Hybrid comes with a bamboo case, is about 80 percent smaller than a typical desktop minitower, and uses 70 percent less energy.

ASUS, a Taiwan-based computer maker, recently introduced the Eco Book, a computer laminated in bamboo strips. Jellen Sun, a senior director for the company, told the London-based Guardian newspaper that the computer was built to address the growing concern about the use of plastics. Bamboo is the most sustainable raw material there is, he told the paper, and therefore they decided to combine bamboo with metal and leave out the plastic. The Eco Book’s use of bamboo evolved from the use of polycarbonate, aluminum-magnesium alloy, carbon fiber, and leather that were used in earlier notebook models. Because bamboo is a natural material, he adds, each computer is unique.
Fabrik, a San Mateo, Calif., manufacturer of digital media storage products, hired Los Angeles-based SKD Designs to design hard drives that used more sustainable materials and had less of an environmental impact during processing. The industrial design firm explored new materials and manufacturing process from injection-molded starch-based biopolymers to vegetable-dyed soft goods. What they came up with was the 500 GB SimpleTech [re]drive, which features naturally finished bamboo for the top and bottom of the unit and aluminum side panels. The cast aluminum side panels serve as a heat sink, allowing the drive to operate without a fan. The extruded central chassis provides a frame onto which the pieces attach – some using a pressure fit to minimize fasteners required in assembly. The use of interchangeable parts, including mirrored panels and identical fasteners, minimizes energy and resources spent in production. Waste aluminum was recycled during manufacturing and mixed up to 30 percent with raw aluminum. Designed so that the materials are separate from one another, it is easy to disassemble and recycle at the end of its life.