Nanotechnology develops both from the bottom up and from the top down. The bottom up approach entails developing nanomaterials using molecules and atoms and an understanding of nanomaterials therefore requires studies in molecular science. A top down approach involves using existing technology to develop means to miniaturize this technology down to the nanometer scale (10-100 nm). Bottom up designed nanoscale materials have unique properties that become apparent only when the material is very small.
A quantum dot’s colour can be changed based solely on changing the size of the nanoparticle (5-10 nm in radius). Nanoscale catalysts are more efficient because of their enormous surface area to volume ratio. These tiny materials will have widespread impact in the energy sector, both in upgrading heavy petroleum and in alternative energy applications. Nanoparticle delivery of anti-cancer agents is an area of rapid development because these particles are naturally attracted to growing tumours, simply because the particles have a 10-100 nm size.