Dartmouth Engineer - The Magazine of Thayer School of EngineeringDartmouth Engineer - The Magazine of Thayer School of Engineering

50 Materials That Make the World

From concrete to celluloid, Professor Ian Baker unearths the history of materials essential to human development.

By Kristen Senz
Photograph by John Sherman

For his new book, 50 Materials That Make the World, materials scientist Ian Baker traded his electron microscope for the tools of a historian, providing readers with a view of the world through the stories of the “stuff” crucial to centuries of human development.

The Thayer School engineering professor and senior associate dean for academic affairs has spent more than three decades studying the microstructures and mechanical properties of metals and ice in research efforts that have ranged from developing high-temperature metal alloys to studying the process by which snow turns to permanent ice on the Greenland ice sheet, to deepen our understanding of past climates. Baker has also studied intermetallic compounds, high-strength magnetic materials, and iron nanoparticles. His far-reaching work has led to the development of new structural materials as well as treatments for hyperthermia and cancer. 

Born and educated in the United Kingdom, Baker said a BBC podcast originally sparked the idea for the book, which was published in September 2018 by Springer. Scientific but accessible to the nonscientist, 50 Materials That Make the World offers an introduction to the broad field of materials science, with each chapter tracing the path of a particular material from discovery to prominence and discussing potential future uses. 

Baker recently spoke with Dartmouth Engineer about his new book and the materials that have fascinated him throughout his career. The conversation has been lightly edited for length and clarity.

What was it that originally attracted you to materials science?

When I was in grammar school in the [United Kingdom]—and grammar school is from age 14 to 18—so when I was about 17 or 18, we did a new physics curriculum that had 10 modules, and one of the modules was on materials science. So I encountered it early and it really interested me. During grammar school, I was studying physics, chemistry, and math—in the United Kingdom, you tend to study only a limited number of subjects in high school—and I couldn’t really decide which of those to do at university. Materials science actually was a combination of all three of those, so that’s why I ended up doing materials science. 

How did the idea for this book come about?

It came about in a strange way. I think the initial genesis was probably about 2010. I listened to a BBC podcast by Neil McGregor, who’s the director of the British Museum, called A History of the World in 100 Objects, in which he talks about objects from the museum. It’s a really great series, because he doesn’t just talk about the object; he talks about the history all around it. So that gave me the idea to start thinking about materials and the history around them. Then there was a book by a professor at Cornell named Steven Sass, who’s now retired, called The Substance of Civilization, which was about how materials had evolved throughout history. That was interesting and got me thinking about doing a book. There were a couple of other books that also helped inspire the content and tone and got me thinking about this kind of project. 

Then, in December 2014, I was one of the organizers of a symposium at the Materials Research Society meeting in Boston. Springer, the publisher, contacted me and asked me if I’d like to write a book on intermetallic compounds, because that was the symposium I was organizing. I thought about that for about 3 milliseconds and said, ‘No, not really.’ I figured it would be a lot of work and maybe about three people would read the book. So I said, how about I write you a book proposal on something else? I wrote the proposal and the working title was, 50 Materials That Make the World

Was it challenging as a scientist to write a book aimed primarily at nonscientists? 

The only other time I’ve ever written anything like this was back in 1991. I wrote an article for New Scientist, a British publication. I sent off my copy to the publisher and it came back with red all over it; probably every other word they put a pen through. I realized how difficult it was to write something like this, because whenever you define something, as a scientist, you use other scientific terms to define scientific terms. Here, I tried to avoid doing that and put things in more straightforward terms—not dumbing it down, but making it accessible. It’s exact, but it doesn’t get hung up on too many details. 

How did you choose the materials to include in the book? 

My initial process was to send a note to all of my colleagues at the engineering school here, asking them to name what they thought were the 10 most important materials. I didn’t tell them why I was asking. Some of them gave me materials such as steel and aluminum and some of them reframed the question and gave me 10 classes of materials. They gave me about 15 or 20 materials total and then I chose others. 

I included some materials that aren’t used very much now but were important at one time. One example of that is gutta percha, which comes from a tree and is sort of like latex, except it’s harder and it’s a thermoplastic—you can heat it up and reform it. When it was first used in the 1850s, it had a huge impact: It was used to coat undersea cables and make golf balls and had a whole bunch of other applications. Now, the only real use is to fill in your root canal, if you have to have one. 

Another example is celluloid, which was invented because someone wanted to replace ivory in billiard table balls, and someone came up with celluloid, which didn’t actually fulfill that purpose at all. But it did spawn the movie industry. They use celluloid to make film and photographs. Celluloid stopped being used for that purpose around 1949, because it’s actually quite flammable, almost explosive in some situations, and it degrades, so other stuff was used after that. Now, celluloid is used only for a few things, such as ping pong balls.

How many of the materials in the book are naturally occurring vs. manmade? 

That’s a good question. I cannot give you a simple answer. It’s an interesting question because you could have something that is naturally occurring but you make it yourself most of the time. For example, graphite is naturally occurring material. You can go mine graphite to put lead in your pencil, but when you make graphite fibers, which are used in tennis rackets or squash rackets and a whole bunch of other things, you make them from a polymer using various heat treatments. It’s similar to natural graphite, but it’s made in a completely different way and has different properties because of the way it’s made. Similarly, rubber is a natural material, but when you use rubber, you normally do cross-linking of the polymer chains, which changes its properties quite a bit. 

Silver, gold, and platinum are naturally occurring materials, which you can just dig out of the ground and they’re used that way. And clay, of course, is a natural material, but you don’t just use it as clay; you normally bake it or do something to it. Steel is iron, but you’ve done a lot to it to get steel, and it’s not like iron at all. 

In doing the research for the book, what did you discover that you didn’t know before?

I think most materials scientists know about the properties of the materials, but they often don’t know a great deal about the history or how they were discovered and came into use.

Some of the most interesting things to me had to do with materials that I don’t really work with, such as wood and concrete. When I started researching wood, I found that there’s this stuff now called engineered wood. It’s sort of like plywood, but it’s bigger slices and the wood is deliberately put in different orientations so that the grain is at 90 degrees in each consecutive layer. They are now building quite a few buildings out of this engineered wood, such as small skyscrapers. They can make fairly tall buildings without a lot of the heavy equipment that is used for steel buildings, because the wood is not as heavy. You can make the wood more fireproof by putting layers of concrete on it as well. 

In concrete, I learned that people are now trying to incorporate bacteria into concrete. So, if you get a crack in the concrete, the bacteria there would interact with the carbon and oxygen in the atmosphere to create a compound that can actually glue the concrete back to together and heal the cracks. 

Can you describe the connection between the properties of a material on the micro level and the way it behaves on the macro level? 

What happens on the microscopic level completely controls what happens on the macroscopic level, for the most part. My main area of expertise is microstructural characterization, and a key part of that is electron microscopy. Nearly all of my projects use electron microscopy and some of them use X-ray techniques as well. Understanding what the microstructure looks like is really key to understanding the behavior on the larger scale. 

A lot of what material scientists do is try to understand the microstructure and come up with models of how that microstructure affects the properties of the material, be they magnetic or mechanical or electronic properties. Once we can understand the microstructure and how it influences the properties of the material, then we can actually do things to change it to make it even better.

What is a material that you think is going to become more prominent in our daily lives? 

Graphite composites are sure to become more prominent. Up until recently, all jetliners—the bodies and the wings and everything—were made out of aluminum alloys. With the latest planes, they’re making them out of composites instead. They can be lighter and they can be less costly to construct, because you can make them all in one big piece. The Boeing 787 Dreamliner was really the first one of those. It might be that cars start to be made out of graphite composites as well. They are expensive materials, but if you can get the manufacturing costs down, maybe that can offset some of the price of the materials. 

How should people approach the materials in the book?

I put the materials in alphabetical order purely for organization, but you should just delve into a particular material you find to be of interest. Maybe you’ll find out a little bit about the history that you didn’t know.


Material Facts


A shopping bag. A jet engine. A billiard ball. 

Have you ever wondered what materials are used to make the things you encounter every day? Here are 10 quick facts from 50 Materials That Make the World.

Camera

ACRYLONITRILE BUTADIENE STYRENE plastic is the most popular engineering polymer, used in camera bodies, keyboards, and many other products.

 

BAKELITE (phenolformaldehyde), the world’s first thermosetting polymer, replaced ivory in billiard balls and is now used in bowling balls. Bakelite kitchenware and jewelry have become collectors’ items.

 

Concrete

Found in roads, bridges, buildings, and more, CONCRETE is the most ubiquitous material on Earth. It is used in larger quantities than the combined weight of all metals used in a year.

 

The metallic compound GALLIUM ARSENIDE is used to make laser pointers, CD and DVD players, and barcode readers.

 

Single crystals of NICKEL-BASED SUPERALLOY are used to make the turbine blades in most jet engines due to their resistance to chemical degradation and high temperatures. 

 

PLATINUM can withstand even higher temperatures—its melting point 1,772 degrees Celsius. Uses include spark plugs, optical fibers, pacemakers, and jewelry. 

 

First synthesized in 1898, POLYETHYLENE is used in plastic shopping bags, milk jugs, tubing, furniture, and other products. Caterpillars that eat polyethylene could help mitigate pollution from these plastics.

 

Ping pong balls

Unsuccessful as a replacement for ivory in billiard balls, CELLULOID instead gave rise to the film industry and is now used in guitar picks and ping pong balls. 

 

Magnets

Nine-tenths of the world’s RARE EARTH MAGNETS, which are used in wind turbines, electric car engines, computer hard drives, microphones, headphones, generators, sensors, MRI machines, and other applications, are mined and produced in China.

 

NITINOL, a common “shape memory” alloy, is used in arterial stents and eyeglass frames, among other applications. The market for nitinol was expected to top $8 billion by 2018.

Kristen Senz is a freelance writer and editor.

Categories: Features

Tags: innovation, material science, Research

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