Nanotechnology in Manufacturing

Nanomanufacturing refers to the production of nanoscale materials and engineered components that display unusual properties at the quantum scale by a variety of means. In the lexicography of nanotechnology, it is one of the less well-defined terms. For example, the Society of Manufacturing Engineers refers to nanomanufacturing as the tools, instruments, metrological devices, and modeling applications that can build complex structures with atomic precision. As such, nanomanufacturing is virtually synonymous with the U.S. National Nanotechnology Initiative's (NNI's) definition of nanotechnology. Although there were no firm conventions governing its usage as of 2010, nanomanufacturing can broadly refer to material practices involving the fabrication of nanoscale materials and structures in small quantities for experimental purposes, and in larger quantities for a variety of commercial applications.

Nanomanufacturing is often subdivided into top-down and bottom-up manufacturing. Top-down processes refer to the creation of nanoscale particles and structures through the reduction of larger pieces of matter and/or the rearrangement of the constituent parts. Nanoscale particles are produced from bulk material by processes such as precipitation, condensation, arc discharge, and laser ablation. Various forms of lithography reduce materials into electronic structures. Bottom-up methods refer to the atom-by-atom construction of nanocomponents without any wasted materials through self-assembly. Currently this is largely a speculative area of research. Technologies such as molecular beam epitaxy, sputtering or physical vapor deposition, and chemical vapor deposition decompose substances and deposit them in layered thin films and, in a broad sense, can be classified as both top down and bottom up.

Nanomanufacturing may be further divided into categories of complexity. One form involves the production [Page 549]of relatively simple nanomaterials in the form of ultrafine powders and coatings that display a variety of properties depending on the materials. High surface area imparts stain, scratch, and corrosion resistance. Small particle size blocks ultraviolet light. Other nanoparticles have micro-bial properties. Many nanomaterials like metal oxides and polymers are simply variants of substances that have been used in bulk for years but are produced as nanoscale particles. As applied in gels, creams, and lacquers, nanoparticles are not precisely engineered nanostructures. As a result, many can be produced and applied by existing chemical and fabrication manufacturing infrastructure. Nanoparticle coatings are one of the largest single sectors of nanomanufacturing, worth perhaps several billion dollars in the global market by 2010. Nanoparticles of clay, silica, metal oxides, and carbon nanotubes used in composite materials to increase strength, reduce brittleness, improve conductivity, and resist combustion represent another relatively large sector of nanomanufacturing.

Another branch of nanomanufacturing focuses on producing novel materials that engineers hope to be able to exploit in macroscale technologies for purposes of energy conversion, power production and conduction, and data storage and processing. This may be termed “disruptive” nanomanufacturing. It involves scaling up the production of novel nanomaterials and integrating them into macroscale technologies, activities that face considerable physical and economic barriers. If fully developed, such systems may compete with existing manufacturing systems. As of 2010, much disruptive nanomanufacturing remained experimental and in various stages of engineering research.