All technologies utilize materials, whether they are linked to information, energy, transportation, consumer products, or medicine. In the second half of the 20th century, the field of materials science and engineering emerged as a discipline. This field seeks to understand how the structure of materials is connected to their properties and thereby enable “materials by design,” with special properties required for particular applications. Important connections have been established between microscale properties such as the structure of metals or the molecular weight of polymers and their respective properties. As a result, materials available today are stronger, lighter, more durable, or have other unique properties that enable applications such as high-speed integrated circuits.
The world of designed materials should be significantly impacted by nanotechnology, leading to materials and devices with significantly advanced properties. Imagine organic, inorganic, and hybrid materials made up of nanostructures that can have prescribed shapes, as proteins do in biology. There have already been some previews in the scientific literature of what these new capabilities may bring. Inorganic nanostructures measuring only a few nanometers (quantum dots) (Figure 4.2.1) have unique optical properties. Recently discovered organic nanofibers mimic collagen fibrils found in our tissues (Figure 4.2.2). These structures may help us create materials that resemble bone for medical applications, but they could also produce bone-inspired hybrid materials in which organic nanofibers guide the organization of quantum dots or other inorganic nanocrystals (Figure 4.2.3). Such hybrid materials, and others such as carbon nanotubes, may someday be part of computers with memories and speeds that are thousands or millions of times greater than the ones we know today or be part of materials that help us improve the energy efficiency of the systems we use everyday.
Figure 4.2.1 Quantum dots.
Figure 4.2.2 Organic nanofibers that mimic collagen fibers.
Figure 4.2.3 Organic nanofibers used to guide the organization of inorganic nanocrystals. SOURCE: All three figures in this box are from Annual Review of Materials Science, Volume 30, 2000. Used by the permission of Annual Reviews, <www.AnnualReviews.org>.