Nanotechnology is an umbrella term that covers many areas of scientific research dealing with objects that are measured in nanometers. A nanometer (nm) is a billionth of a meter, or a millionth of a millimeter. Generally speaking, nanotechnology is a science concerned with the process of creating minuscule machines from individual atoms.
Two main approaches are used in nanotechnology. In the "bottom-up" approach, materials and devices are built from molecular components (which assemble themselves chemically by principles of molecular recognition). In the "top-down" approach, nano-objects are constructed from larger entities (without atomic-level control).
Examples of nanotechnology in modern use are the manufacture of polymers (plastics, DNA and proteins) based on molecular structure, and the design of computer chip layouts based on surface science. Despite the great promise of numerous nanotechnologies (such as quantum dots and nanotubes), real commercial applications have mainly used the advantages of colloidal nanoparticles in bulk form, such as suntan lotion, cosmetics, protective coatings, and stain resistant clothing.
More specifically, nanotechnology is a hybrid science combining engineering and chemistry. It works like this: Atoms and molecules stick together because they have complementary shapes that lock together, or charges that attract. Just as with magnets, a positively charged atom will stick to a negatively charged atom. As millions of these atoms are pieced together by nanomachines, a specific product will start to take shape. The goal of nanotechnology is to individually manipulate atoms and place them in a pattern to produce a desired structure. There are three steps to achieving nanotechnology-produced goods:
Scientists must be able to manipulate individual atoms. This means that they will have to develop a technique to grab single atoms and move them to desired positions. In 1990, IBM researchers showed that it is possible to manipulate single atoms. They positioned 35 xenon atoms on the surface of a nickel crystal, using an atomic force microscopy instrument. These positioned atoms spelled out the letters "IBM."
The next step will be to develop nanoscopic machines, called assemblers, that can be programmed to manipulate atoms and molecules at will. It would take thousands of years for a single assembler to produce any kind of material one atom at a time. Trillions of assemblers will be needed to develop products in a viable time frame. In order to create enough assemblers to build consumer goods, some nanomachines, called replicators, will be programmed to build more assemblers.
Historical perspective: In 2014, scientists created a new liver-like device that can remove dangerous toxins from the blood. Combining nanotechnology and 3-D printing, researchers at the University of California, San Diego, revealed a new liver-like device that can remove dangerous toxins from the blood. It's a potential boon for victims of "animal stings, bacterial infections, and other toxic horrors," said Steve Dent at Engadget. Used outside the body like a dialysis machine, the device acts as a faux liver, cleansing the blood by attracting and capturing toxins. Though still in early development, a test model successfully destroyed all toxins in multiple studies.