The basis of materials science

Engineers Week – an event first celebrated in 1951 by the National Society of Professional Engineers – was held on February 20th-26th2022 The theme of this year’s event was ‘Reimagining the Possible’, highlighting the ways engineers are making a difference in the world.

The goal was to engage children with engineering and STEM topics and activities. To mark the occasion, this article discusses the significant impact of materials science engineers and outlines some of the most recent advances in the field.

Materials science is at the heart of almost everything

The universe does not simply divide into clearly defined silos. Thus, the field of materials science comprises a wide range of applications, from crystal structures critical to semiconductors to titanium alloys, from discoveries in nanotechnology to the development of sustainable bioplastics, and from metal lenses to color-tunable LEDs. Materials science has helped shape the modern world.

This interdisciplinary field—also known as “materials science and engineering”—combines elements of both chemistry and physics and concentrates on the design and discovery of new materials (especially solids). It has been described as “using the periodic table as a grocery store and the laws of physics as its cookbook.”1

One of the earliest examples of materials science – long before the term was known – was the production of bronze around 3,500 years ago. Composed of copper and lead, this metal alloy was stronger than copper, thus allowing Bronze Age craftsmen to forge and melt it into practical tools and objects, and helped advance human civilization.

Examples of materials science from different eras: a Bronze Age ax head (left) and a revolutionary ultra-thin “mesh” achromatic metals recently developed at UC Berkeley (right, scale bar represents 5 micrometers). Image credit: Radiant Vision Systems

The basis of information technology

Modern materials science effectively helped create the computer and consumer electronics industry. It all started with the development of an ultra-pure form of silicon (now called electron-grade silicon), which is produced by eliminating impurities such as boron, phosphorus and carbon. To manufacture integrated circuits, silicon must contain <0.1 parts per trillion of these materials.

Between 1955 and 1990, improvements and innovations in semiconductors “increased the performance and reduced the cost of electronic materials and devices by a factor of one million—an achievement unparalleled in the history of human technology.”2

To put that into perspective, Applied Materials CTO Omkaram Nalamasu explains, “To create today’s smartphone in the 1980s would cost about $110 million, require nearly 200 kilowatts of energy (compared to 2 kW per year today) and the device will be 14 meters high.3

Today, telecommunications infrastructure and systems depend on “various crystalline semiconductors; metallized film conductors; dielectric films; solder joints; ceramics and polymers formed into substrates on which circuits are assembled or printed; and gold or copper wires and cables.4

The main material in a significant number of LEDs and display devices is indium gallium nitride (InGaN) – a manufactured mixture of gallium nitride and indium nitride. When grown in crystals, InGaN facilitates the band tuning required to emit light in the infrared, visible, and ultraviolet spectrum.

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

A blue LED made possible by the indium gallium nitride alloy. Image credit: Radiant Vision Systems

Materials scientists are persistent in their quest to construct new smart materials with properties not commonly 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.

Graphene is a remarkable material because “it is 200 times stronger than steel by weight. Over the last 10 years, we have been able to use graphene to make new types of electronics, very high performance transistors, new types of sensors and new types of composites based on its unique properties.5

A flexible, transparent sheet of graphene in the lab.

A flexible, transparent sheet of graphene in the lab. Image credit: Radiant Vision Systems

Recent Advances in Materials Science

We then present a number of examples of emerging applications and recent technological innovations where materials science has played a key role.

Safer than lithium batteries

Lithium-ion batteries are the primary power source for most modern electronic devices and vehicles. However, they have two major drawbacks: first, they contain a liquid electrolyte that can be extremely flammable, and second, the global lithium supply chain can lead to increased geopolitical tensions.

Recently, a group of researchers at the University of Geneva developed a solid electrolyte material that exhibits the conductive properties needed for batteries. The material (carbo-hydroborate) is produced using sodium, an element that is cheaper than lithium and abundant almost everywhere on earth.

“Frozen smoke” aka aerogels

A diverse group of porous materials, aerogels are considered the lightest solids in the world, consisting of up to 99.98% air by volume and possessing unique special properties.

For example, “Transparent superinsulating silica aerogels exhibit the lowest thermal conductivity of any known solid. Ultra-high surface area carbon aerogels power today’s fast-charging supercapacitors. And the ultra-strong, bendable x-aerogels are the lowest-density structural materials ever developed.”6

Unlike garden gels, aerogels are dry and consist of a rigid, low-density gel framework that remains after the moisture is extracted.

NASA uses silica-based aerogels to insulate the rover, and they have been used as an absorbent in cleaning up chemical spills.

Additionally, “carbon aerogels are being used in the construction of small electrochemical double-layer supercapacitors. Due to the large surface area of ​​airgel, these capacitors can be 2000 to 5000 times smaller than similarly rated electrolytic capacitors. Airgel supercapacitors can have very low impedance compared to normal supercapacitors and can absorb/produce very high peak currents.7

Block Silica Airgel

Block Silica Airgel. (Fig source).

Foldable displays

LG Chem (a subsidiary of LG Display) has created a new cover for foldable screen devices such as smartphones and laptops. Known as the “True Folding Window”, it is produced by applying special coating materials to PET film (a thin type of plastic) to produce a surface as rigid as glass but with the flexibility of plastic.

The material is designed to overcome device-related issues such as crease marks or cracks in the hinged part of the screen. It also improves the coating’s heat resistance and other mechanical properties.

To make the impossible possible

MIT-based engineers have applied a new polymerization process to produce an entirely new material that is stronger than steel but lighter than plastic. It can be easily produced in significantly large quantities and could potentially revolutionize the industrial landscape.

Applications include lightweight, durable coatings on everything from bridges and infrastructure to automotive parts and mobile phones. Effectively a new form of plastic, the polymer has the ability to self-assemble into 2D sheets – a process scientists thought was impossible, hence its nickname “Impossible Plastic”.

An

An “impossible” two-dimensional polymer film that is twice as strong as steel but as light as plastic. (Fig source)

This article lists just some of the latest materials developments that scientists and engineers are working on in laboratories and research facilities around the world. Amazing new substances are being developed every day with the potential to revolutionize medicine, technology and industry and help create a more sustainable planet.

References

  1. Diamandis, P., “3 Big Breakthroughs in Materials Science – And Why They Matter for the Future,” SingularityHub, 21 May 2020.
  2. Computing and Communications Materials, Britannica. (Accessed until February 16, 2022)
  3. There again.
  4. Diamandis, P., “3 Big Breakthroughs in Materials Science – And Why They Matter for the Future,” SingularityHub, 21 May 2020.
  5. Diamandis, P., “Convergence of Materials Science and Technology”. Blog post March 23, 2016 (Accessed February 16, 2022)
  6. Aerogel.org. (Accessed until February 16, 2022)
  7. “Aerogel”. New World Encyclopedia. (Accessed until February 16, 2022)

This information was obtained, reviewed and adapted from materials provided by Radiant Vision Systems.

For more information on this source, please visit Radiant Vision Systems.

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