In this blog post, we’ll examine the importance of material selection in determining an invention’s performance, durability, and price. Using graphene and flexible displays as examples, we’ll take a closer look at the specific role materials engineering plays in transforming new technologies into actual products.
It is no exaggeration to call the 20th century the golden age of science, as it was a time of dazzling scientific progress. Driven by these advancements, countless inventions—from automobiles to computers and cell phones—appeared one after another, making human life far more convenient. However, the creation of these numerous inventions that have enriched our lives required a great deal of effort and research that we often take for granted. If asked to name a few processes necessary for creating innovative inventions, people often think of establishing theories or mechanical and structural design. However, an invention is not completed by theory and design alone. To actualize a product, materials capable of withstanding the required performance are essential. The selection of materials is one of the key factors that determine a device’s price, durability, weight, electrical properties, thermal properties, and manufacturability. Materials engineering is the discipline that develops new materials and studies the relationships between a material’s structure, properties, manufacturing methods, and performance in order to make these material selections more effective.
When people are asked how much they know about materials engineering, many immediately think of semiconductors. Given the significant role semiconductors play in modern industry, it is only natural that they have become one of the defining images of materials engineering. It is also true that South Korea has long built competitiveness in the semiconductor industry and related research fields, achieving considerable industrial and economic success as a result. However, semiconductors are just one of the many research areas covered by materials engineering. In fact, a look at the applications of materials engineering reveals that it is widely utilized across the entire spectrum of engineering—not only in semiconductors but also in metals, polymers, ceramics, electronic materials, energy materials, and biomaterials. Even products as diverse as automobiles, aircraft, batteries, displays, medical devices, and buildings ultimately require the selection of materials suited to their purpose and the control of those materials’ properties to achieve the desired performance. So, what exactly does materials engineering—which plays such a crucial role across the entire field of engineering—study, and how does it turn the potential for new inventions into reality?
Back when Samsung Electronics’ Anycall AMOLED cell phones first appeared, advertisements and videos showcasing futuristic cell phones often featured people rolling up their phones to wear them on their wrists like watches, or unrolling them from their wrists when needed to unfold the screen and use it in a larger, expanded format. Scenes of folding and unfolding screens—or sometimes rolling them up or stretching them out—seemed like technology from a distant future at the time. Watching such scenes, it was natural to wonder, “Can a cell phone like that really be made?” However, as time passed, some of the technologies that were once mere fantasies have become a reality. Today, foldable smartphones—which allow users to fold and unfold the screen—have already established themselves as commercial products, and technologies that enable the display itself to bend or transform into various shapes continue to advance. However, we have not yet reached the stage where products that allow users to freely wrap a phone around their wrist or expand the screen size at will—as depicted in those commercials—have become widely available as mainstream smartphones. At the core of today’s foldable smartphones lie various material technologies, including flexible OLEDs, flexible polyimide-based substrates, ultra-thin glass that has been thinned and reinforced, and adhesives and support structures capable of withstanding repeated bending. Looking at the process by which products that once seemed like mere fantasies have become reality, it becomes clear that materials engineering is the foundational technology enabling new forms of devices.
Anyone interested in science has likely heard the name “graphene” at least once. Graphene has long been studied as a material with great potential for use in next-generation electronic devices, energy materials, composite materials, sensors, and flexible electronics. However, even if you know the name “graphene,” it is not easy to explain exactly what kind of material it is. The name “graphene” is derived from “graphite,” which refers to graphite, and the suffix “-ene,” used to name compounds containing carbon double bonds. Graphite is a material consisting of multiple layers of thin sheets in which carbon atoms form a hexagonal honeycomb structure; graphene can be understood as a material corresponding to a single layer of these carbon atoms that make up graphite. It is a representative two-dimensional material in which carbon atoms are arranged in a hexagonal lattice on a plane, and the effective thickness of a single layer is generally described as approximately 0.34 nanometers. Considering that 1 nanometer is one-billionth of a meter, it is an extremely thin material. Graphene began to attract significant attention when research into isolating graphene—at the single-atom-layer level—from graphite and experimentally verifying its properties gained momentum. Since then, research on manufacturing technologies to synthesize graphene over larger areas and control its quality and defects has continued to advance. Now that we have a general understanding of what graphene is, we need to examine why it has become such an important subject of research in materials engineering.
The primary reason graphene has garnered so much attention is that it exhibits several outstanding physical properties simultaneously within its extremely thin structure. Graphene has very high electrical conductivity—comparable to copper or, under certain conditions, even superior—and in high-quality graphene, the mobility of charge carriers can be significantly higher than that of silicon. In fact, its electronic transport properties are so exceptional that research has shown electrons can move more than 100 times faster in graphene than in silicon. Its mechanical strength is also very high; based on the tensile strength of ideal single-layer graphene, it is often described as a material approximately 200 times stronger than steel. It also has excellent thermal conductivity and, thanks to its flexibility and elasticity, offers the advantage of being bendable and deformable. However, since these figures can vary depending on factors such as graphene quality, defects, measurement methods, substrates, and temperature, one should not simply assume that all graphene products exhibit the same performance. Furthermore, today’s commercial foldable smartphones are not made possible by graphene alone. Current foldable devices are the result of the combined advancement of various material technologies, including flexible OLEDs, flexible substrates, ultra-thin glass, metal and polymer materials, adhesive layers, and hinge structures. Nevertheless, graphene’s high electrical, thermal, and mechanical performance, along with its flexibility, is still considered a key area of research in various fields, such as next-generation flexible electronic devices, sensors, and composite materials. Materials engineering plays a crucial role not only in creating new materials but also in precisely characterizing their properties and designing manufacturing processes and structures to ensure their practical application in industry.
The rapid scientific advancements of the 20th century brought humanity a convenient lifestyle that was previously hard to imagine, and today people enjoy the fruits of these achievements in every aspect of their daily lives. However, the progress of science and engineering never stops. People want devices that are lighter, stronger, faster, and more durable, while at the same time demanding products that deliver high performance while consuming less energy and fewer resources. To meet these demands, new designs alone are not enough. We must either develop new materials that transcend the limitations of existing ones or modify the structure and composition of existing materials to achieve the required performance.
Sometimes, rather than creating an entirely new substance, the key solution lies in appropriately combining different materials, adjusting thickness and microstructure, and improving manufacturing processes. Ultimately, materials engineering plays a pivotal role in opening the door to new inventions and in transforming theory and design into actual products. If a new idea is the starting point of an invention, the process of ensuring that idea works in the real world and can be used for a long time always requires the right materials and the engineering expertise to understand them. This is precisely why materials engineering will inevitably continue to serve as the foundation for new inventions and technological innovation.
