INTRODUCTION

The concepts behind nanotechnology were first laid out by the Nobel Prize–winning physicist Richard Feynman in 1959, when he proposed that it was theoretically possible to engineer matter at the atomic scale. However, scientists were unable to explore the realm of the super-small until the 1980s, when new instruments allowed humans to view and manipulate atoms. It was around that time that scientists also discovered the first nanoparticles, molecules within the nanoscale range that are used for a variety of nanotech applications.

At the nanoscale level, matter begins to exhibit properties, or characteristics, different from those found at larger scales. A gold nanoparticle, for instance, has a different color and melting point than a gold nugget. These novel properties can be exploited by incorporating nanoparticles into larger structures.

Researchers use either the “top-down” or the “bottom-up” method of fabricating structures at the nanoscale. In the top-down approach, a larger structure is precisely whittled away, leaving the desired product. In the bottom-up approach, individual atoms and molecules are put together piece by piece. This method often requires “self-assembly,” where the components naturally assume the desired arrangement due to their size and shape, in addition to the laws of physics and chemistry. Both methods have advantages, although the top-down approach is easier to control.