Making Nanomaterials
With the development of the Scanning Tunneling Microscope (STM) and other scanning probe instruments came the ability to not only study materials at the nanoscale but also to construct nanomaterials and manipulate them to enhance their unique properties. Scientists working in the laboratory now have the ability to build nanostructures by moving around molecules. And such activities can be scaled up so that nanomaterials can be manufactured in factories and put into products.
There are generally two approaches to nanomaterial construction, top-down and bottom-up. Top-down construction involves working like a sculptor and chiseling nanomaterials out of a bulk material. Microchip manufacturing is the most common example of this top-down approach to producing nanomaterials. While this is an effective approach for some industries, there are limits to the amount of chiseling that can be done and the process is generally labor and cost intensive.
The bottom-up approach to nanomanufacturing uses self-assembly to arrange nanoparticles into various arrangements spontaneously. Self-assembly is accomplished by coaxing the molecules to their lowest energy state and making molecules reorient naturally. Carbon nanotubes are examples of nanomaterials that are manufactured using the bottom-up approach. The trick with bottom-up manufacturing is understanding the chemical and physical properties of nanoparticles and manipulating them to self-assemble. Neither the top-down nor bottom-up approach is superior at the moment each has its advantages and disadvantages. However, the bottom-up approach is said by some to have the potential to be more cost-effective in the future.
Manufacturing products with nanotechnology remains one of the largest hurdles to widespread production. Creating the products in the laboratory is difficult enough and requires highly advanced tools and meticulously clean environments. Scaling these processes up so that factories can mass produce nanoproducts is an even greater challenge and one that continues to confound many developers. The most successful mass production of nanotechnology to date has occurred in computer microprocessors where companies have been able to etch circuitboards at 65 nm or smaller.
Further Reading:
- Ratner, Mark, and Daniel Ratner. 2003. Nanotechnology: A Gentle Introduction to the Next Big Idea. Upper Saddle River, NJ: Prentice Hall
