Engineering Week: Spotlight on Materials Science

I have a confession: I am not an engineer. I was a humanities major, and even though I’ve taken physics and chemistry courses, and worked in high tech, engineering, and scientific arenas most of my career, I had never heard of materials science—not until my first week at Radiant. Since then, I’ve come to know and appreciate how incredibly fundamental the field of materials science and engineering is—not only in the technology industry but in almost every aspect of the modern physical world.

Engineers Week

February 20-26, 2022, is Engineers Week, an event first celebrated in 1951 by the National Society of Professional Engineers. This year’s theme of “Reimagining the Possible” spotlights the ways engineers are making a difference in the world and seeks to engage kids with engineering and STEM topics and activities. To mark the event, this blog post discusses the vital impact of materials science engineers and spotlights some of the most recent advancements in the field. 

Materials Science Underlies Pretty Much Everything

The universe doesn’t divide itself up into neatly defined silos. Accordingly, the field of materials science encompasses a wide range of applications from the crystal structures essential to semiconductors, to titanium alloys; from nanotech breakthroughs to the development of sustainable bioplastics; from metalenses to color-tunable LEDs. Materials science has helped create the modern world. 

This interdisciplinary field—also called “materials science and engineering”—combines aspects of both chemistry and physics and focuses on the design and discovery of new materials (especially solids). It’s been described as “using the periodic table as its grocery store and the laws of physics as its cookbook.”¹

One of the earliest examples of materials science—although long before the term existed—was the fabrication of bronze about 3,500 years ago. Composed of copper and lead, the new metal alloy was stronger than copper, enabling Bronze Age craftsmen to hammer and smelt it into useful tools and objects and helping to propel the development of human society. 

Examples of materials science from different eras: Bronze-age axe head (left), and a breakthrough ultra-thin “fishnet” achromatic metalens recently developed at UC Berkeley (right, scale bar represents 5 micrometers).

The Foundation of Information Technology

Modern materials science essentially created the computer and consumer electronics industry, starting by developing an ultra-pure form of silicon (now called electronic-grade silicon) by removing impurities such as boron, phosphorous, and carbon. To make integrated circuits, silicon must contain <0.1 part per trillion of these materials. 

Between 1955 and 1990, improvements and innovations in semiconductors “increased the performance and decreased the cost of electronic materials and devices by a factor of one million—an achievement unparalleled in the history of human technology.”² For a sense of perspective, Applied Materials CTO Omkaram Nalamasu has said, “To build today’s smartphone in the 1980s, it would cost about $110 million, require nearly 200 kilowatts of energy (compared to 2kW per year today), and the device would be 14 meters tall.³  

Today’s telecommunications infrastructure and systems depend on “various crystalline semiconductors; metalized film conductors; dielectric films; solders; ceramics, and polymers formed into substrates on which circuits are assembled or printed; and gold or copper wiring and cabling.”⁴ At the core of many LEDs and display devices is indium gallium nitride (InGaN)—a fabricated mixture of gallium nitride and indium nitride. When grown into crystals, InGaN enables the kind of bandgap tuning needed to emit light across the infrared, visible, and ultraviolet spectra. 

A blue LED, made possible by the alloy indium gallium nitride.

Materials scientists continue to engineer smart, novel materials with properties not found in nature. For example, graphene is a two-dimensional version of diamond or graphite, a one-atom-thick layer of carbon in a hexagonal lattice structure. Remarkably, “it is 200x stronger than steel by weight. Over the last 10 years, we've been able to use graphene to make new kinds of electronics, very high-performance transistors, new kinds of sensors, and new kinds of composites based on its unique properties.”⁵

A flexible, transparent sheet of graphene in the lab.

Recent Materials Science Advancements

The following are few examples of emerging applications and recent technology advancements where materials science has played a defining role.

Safer than Lithium Batteries

Lithium-ion batteries power most of our electronic devices and vehicles. They have two major shortcomings, however. One, they contain a liquid electrolyte that can be highly flammable. And two, the global lithium supply chain can pose geopolitical tensions.

Now, researchers at the University of Geneva have developed a solid electrolyte material that exhibits the conductive properties necessary for batteries. The material (carbo-hydridoborate) is made from sodium, an element that is less expensive than lithium and found in abundance anywhere on earth. Learn more…

“Frozen Smoke” aka Aerogels

A diverse class of porous materials, aerogels are the world’s lightest solids, composed of up to 99.98% air by volume and possessing special properties. For example, “Transparent super-insulating silica aerogels exhibit the lowest thermal conductivity of any solid known. Ultrahigh surface area carbon aerogels power today's fast-charging supercapacitors. And ultra-strong, bendable x-aerogels are the lowest-density structural materials ever developed.”⁶ Aerogels are dry (unlike garden-variety gels) and consist of the low-density solid framework of a gel that remains after the moisture is extracted.

A block of silica aerogel (Image source).

NASA used silica-based aerogels for insulation on the Mars rover, they have been used as an absorbent to clean up chemical spills, and “carbon aerogels are used in the construction of small electrochemical double layer supercapacitors. Due to the high surface area of the aerogel, these capacitors can be 2,000 to 5,000 times smaller than similarly rated electrolytic capacitors. Aerogel supercapacitors can have a very low impedance compared to normal supercapacitors and can absorb/produce very high peak currents.”⁷

Folding Displays

LG Chem  (sister company of LG Display) has developed a new cover window for foldable-screen devices such as smartphones and laptops. Called “Real Folding Window,” it’s made by applying special coating materials to PET film (a thin type of plastic) to make the surface as hard as glass yet as flexible as plastic. The material is intended to improve device issues such as fold impressions or cracks at the hinged part of a screen. It also enhances heat resistance and other mechanical properties of the cover. Learn more…

Making the Impossible Possible

Engineers at MIT have used a novel polymerization process to create an entirely new material that is stronger than steel and lighter than plastic. It can be easily manufactured in large quantities and has the potential to revolutionize the landscape around us. It could be used as a lightweight, durable coating on everything from car parts and cell phones to bridges and infrastructure. Essentially a form of plastic, the polymer can self-assemble into 2D sheets—a process scientists had previously believed to be impossible, thus its nickname “Impossible Plastic.” Learn more…

“Impossible” two-dimensional polymeric film that is twice as strong as steel but as light as plastic. (Image source)

These are just a few of the latest developments materials scientists and engineers are working on in laboratories and research facilities around the globe. Expect to hear about more amazing new substances with the potential to transform medicine, technology, and industry, and help create a more sustainable planet. 

 

CITATIONS

1. Diamandis, P., “3 Major Materials Science Breakthroughs—and Why They Matter for the Future,” SingularityHub, May 21, 2020.
2. Materials for computers and communications, Britannica. (Accessed February 16, 2022) 
3. Ibid.
4. Diamandis, P., “3 Major Materials Science Breakthroughs—and Why They Matter for the Future,” SingularityHub, May 21, 2020.
5. Diamandis, P., “Materials Science and Technology Convergence.” Blog post, March 23, 2016. (Accessed February 16, 2022)
6. Aerogel.org. (Accessed February 16, 2022)
7. “Aerogel,” New World Encyclopedia. (Accessed February 16, 2022)