Nanomaterials are materials with a structure in the nanometer scale. The term “nano” originates from the Greek word "νᾶνος" for "dwarf". Nanomaterials exhibit mechanical, optical and electrical properties that differ distinctively from those of the corresponding bulk materials.
Although nanomaterials also occur naturally (e.g. the light-sensitive pigments inside plants enabling photosynthesis), the research area of nanomaterials focuses mainly on engineered nanomaterials.
Nanomaterials can be manufactured either via a top-down fabrication approach or a bottom-up approach.
While the top-down approach is using microfabrication techniques like photolithography to downscale the material, the bottom-up approach involves assembling atoms and molecules into the desired nanostructure.
Usually, nanomaterials are categorized according to their dimensions. This is based on the number of dimensions that are not confined in the nanometer scale (<100nm).
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