When you hear the word nanotechnology, do you think of hoards of invisible microscopic robots collectively acting out some Hollywood scheme? At the present time in our technology, there are some machines which have been constructed in the nanometer size scale. That said, there are none which are capable of any collective or even constructive work resulting in them being only in the novelty category for the current state of the art. For example, even though the university of California in Berkeley did build an electric motor approximately 500 nm on a side, there really isn’t any commercial use for such a device at the moment. Other nanotechnology includes a cylinder which can be rolled one direction and back on demand or sets of gears which can be turned this way and that. These devices sound pretty cool but they are limited to the surface of a computer chip. Having an engine, device or machine which cannot leave the surface of a computer chip does not quite live up to the hopes from science fiction placed on this technology (at least not yet). If there was useful work a little mobile device could do while it remained on the surface of a computer chip, then some commercial application could be pursued, the real goal is to get the devices to operate off of the surface of the computer chips.
Let’s put these units into some appropriate scales to get some perspective on the level of achievement being discussed here for nanotechnology. A human hair is 0.1 mm (a tenth of a millimeter), most nanotechnology refers to things designed at the levels of much less than one thousandths of this size (or less than 100 nanometers). Going from the other direction, individual atoms have a diameter of around one tenth of a nanometer. Most molecules which are gaseous at room temperature have an average diameter less than one full nanometer. An antibody in your blood stream is about 10 nm, a virus is around 100 nm, bacteria are around 1,000 nm and a red blood cell is around 10,000 nm (or approximately one tenth of the diameter of a human hair). So developing technology on the scale of 100′s of nanometers or less (much much smaller than a human cell) is in all respects, entirely impressive (even if currently constrained to the surface of a computer chip).
The smallest a light microscope can see is many hundreds of nanometers so they cannot really resolve true nanotechnology. To see things the size of a virus or smaller (down to individual atoms), special electron microscopes have been developed which use quantum tunneling to measure locations of surfaces on those scales. These kinds of devices use the wave nature of electrons to cause them to move to the detector enabling to not only be seeing the surface of atoms but even the ability with an atomic force microscope to individually pick up and move single atoms one at a time.
Most nanotechnology today which has shown practical use comes in manufactured materials. Constructing nanoparticles with unique properties has shown great promise for commercial use. Some examples of these are microscopic tabs which have gold whiskers which when two are pressed together, the stick like Velcro at the microscopic level and create an electronic connection as better than a traditional soldered joint (which is what we currently have in all our common electronics). Another promising approach is the use of polymers with nanostructured membranes or carbon nanotubes which enable drug delivery inside the body to be more controlled and dragged out over time when need be. Graphene has the promise of being a nanomaterial which can revolutionize transistor technology and enable manufacturing flexible solar cells in a cost competitive manner. Nanoparticles have also been shown to have electrical resistive properties which could substantially improve insulator properties for high voltage transmission lines. Graphene has even been reported to have the capacity to be stronger than steel under certain conditions.
Graphene, bucky balls and nanotubes are all made of pure carbon atoms. The future use of these is really not certain but does appear more promising than nanobots but it is not unreasonable to assume practical uses will be found as the technology continues to develop.