Nanotechnology

An Overview

          Nanotechnology is the manipulation of matter on the nanoscale. A nanometer is a very small measure of length-it is one billionth of a meter, a length so small that only three or four atoms lined up in a row would be a nanometer. So, nanotechnology involves designing and building materials and devices where the basic structure of the material or device is specified on the scale of one or a few nanometers. Ultimately, nanotechnology will mean materials and devices in which every atom is assigned a place, and having every atom in the right place will be essential for the functioning of the device. Nanotechnology cannot be defined as a definite branch of science but different from the conventional ones that we have as of now. It is set to encompass all the technological aspects that we have today and is nothing but the extension of scientific applications to a microscopic scale and thereby reaching closer to perfection if not right there.

Nanomachines: An Insight

          Nanomachines are machines of dimensions in the range of nanometers. They include micro scale replicas of present day machines like the nanogears,nanoarms or the nanorobots as well as futuristic machines which have no present day analogs, like the assembler which can assemble atoms to produce further machines or assembler themselves.

Carbon Nanotubes

          In 1991, a Japanese scientist Sumio Iijima used a high-resolution transmission electron microscope to study the soot created in an electrical discharge between two carbon electrodes at the NEC Fundamental Research Laboratory in Tsukuba, Japan. He found that the soot contained structures that consisted of several concentric tubes of carbon, nested inside each like Russian dolls. These were termed as ‘Carbon Nanotubes’.

          Later efficient ways of making large quantities of these multiwall nanotubes were developed. Subsequently, 1993, single-wall nanotubes were tens of nanometers across, the typical diameter of a single-wall nanotube was just one or two nanometers. The past decade has seen an explosion of research into both types of nanotube.

Hurdles And Challenges

          An important challenge to overcome is one of engineering. How can we physically build machines out of atoms? Rearranging atoms into new shapes is essentially building new molecules and this is no easy task. Using contemporary technology to rearrange atoms has been said to be analogous to assembling LEGO blocks while wearing boxing gloves. It is virtually impossible to snap individual atoms together. All we can do is crudely push large piles of them together and hope for the best. Scientists hope that once this initial challenge is overcome, nanomachines will usher in a new age of molecular engineering and previous problems will be a thing of the past. The new machine will allow scientists to take off the boxing gloves and accurately snap together individual atoms to build virtually any molecule.

In order to make new molecules, a nanomachine has to somehow ‘grab individual atoms with its pincers and move them into new positions or attach them to other molecules.  There are serious problems that need to be overcome. Consider, for example, the fact that a nanomachine’s pincers will be made out of several atoms and will therefore be larger than the individual atoms that it needs to move around. This means that the intricacy and accuracy of the nanomachines movement will be severely limited. It will be clumsy. Assembling atoms would be like trying to piece together a mechanical wristwatch with your fingers rather than small tweezers.

Synthesis Of Nanomachines

The present generation micromachines which fall in the category of nanomachnes in the sense that they are made by molecular technology are currently synthesized by means of chemical reactions. As of now, chemical synthesis is conducted almost exclusively in solution, where reagent molecules move by diffusion and encounter one another in random positions and orientations.

Conclusion

          All the applications mentioned in this paper exhibit a wealth of properties and phenomena. While many of these are understood, others remain controversial, and all these fields are sure to remain an exciting area of science for years to come. The amazing predictions discussed are not in doubt. Like any new technology, however many of these have to outperform current technologies to gain a foothold. All these challenges will keep researchers busy for a long time to come.