Materials science explores why materials behave the way they do and how their structure can be changed to improve their properties.
Materials science connects physics, chemistry, engineering, and biology to study the substances used to build tools, machines, electronics, buildings, medical devices, clothing, and countless other products. Scientists examine how atoms are arranged, how materials respond to heat and force, how they conduct electricity, and how they change over time. By understanding these relationships, researchers can design materials that are lighter, stronger, safer, more efficient, or better suited to a particular job.
Metals are often strong, workable, and good conductors of heat and electricity.
Learn MoreCeramics can withstand high temperatures and wear but are often more brittle than metals.
Learn MorePolymers include plastics, rubbers, fibers, and many natural materials made from long molecular chains.
Learn MoreComposites combine different materials so their useful properties can work together.
Learn MoreSemiconductors can control electrical current and form the foundation of modern electronics.
Learn MoreMaterials engineered at extremely small scales can show properties unlike those of larger pieces of the same substance.
Learn MoreMetals such as iron, aluminum, copper, and titanium are important because many can be shaped without breaking and can carry heat or electricity efficiently. Their properties depend on how their atoms are arranged and on the presence of other elements. Mixing elements to form alloys can change strength, hardness, corrosion resistance, or weight. Steel, for example, is based mainly on iron and carbon, while many aluminum alloys include small amounts of other elements to improve performance.
Ceramics are inorganic, nonmetallic materials that include products such as glass, porcelain, bricks, and advanced technical ceramics. Many ceramics resist heat, corrosion, and wear very well, which makes them useful in furnaces, electronics, engines, and protective coatings. Their strong atomic bonds can also make them brittle, meaning they may crack rather than bend under certain kinds of stress. Modern ceramics can be engineered for specialized electrical, optical, and medical uses.
Polymers are materials made from long chains of repeating molecular units. Some occur naturally, including cellulose in plants and proteins in living things, while many familiar plastics are synthetic polymers. By changing the chemical structure, chain length, branching, and additives, scientists can create polymers that are flexible, rigid, transparent, heat-resistant, or lightweight. Recycling polymers can be challenging because different plastics have different compositions and may degrade when repeatedly heated and processed.
A composite combines two or more materials that remain distinct but work together. Reinforced concrete combines concrete with steel, while fiberglass combines glass fibers with a polymer resin. Carbon-fiber composites use strong carbon fibers embedded in a surrounding material, producing structures that can be both light and stiff. Engineers choose composites when a single material cannot provide the desired balance of strength, weight, durability, and cost.
Semiconductors conduct electricity better than insulators but not as freely as ordinary conductors such as copper. Their electrical behavior can be carefully controlled by temperature, light, electric fields, and tiny amounts of added elements. Silicon is the most widely used semiconductor in computer chips and many electronic devices. By arranging semiconductor regions into transistors and other components, engineers can switch and process electrical signals at extremely small scales.
Nanomaterials contain structures measured on the scale of billionths of a meter. At that size, surface effects and quantum behavior can become especially important, causing a material to interact with light, electricity, heat, or other substances differently than it does at larger scales. Graphene, a one-atom-thick sheet of carbon atoms arranged in a honeycomb pattern, is one well-known example studied for its unusual electrical and mechanical properties. Nanomaterials are researched for electronics, medicine, energy storage, sensors, coatings, and many other applications.