Materials engineering is traditionally the manipulation of metals, and research in this field is still ongoing. Materials engineers work with mining engineers to develop new metal alloys and use unusual metals for novel purposes. New techniques in ingot casting, foundries, blast furnace extraction, and electrolytic extraction are always being developed. By varying the amounts of various impurities in common metals, new alloys of steel, aluminum, titanium, and copper are being made and uses found.
Other than metals, polymers and nanotechnology are the other hot fields of research in materials engineering. New polymers are constantly being developed and uses found for them, and there is close collaboration between materials engineers and the plastics industry. There is constant development in polymers such as polyethylene, polypropylene, nylons, polyesters, and polycarbonates.
New advances in nano- and microtechnology include the creation of new and faster computer chips, medical devices, and sanitary filters. Materials engineers and nano-scientists work closely together on these projects.
Materials engineers also work with creating new biomaterials for use in the medical industry, such as breast implants, skin repair vehicles for burn victims, joint replacements, and artificial ligaments and tendons.