Nanotechnology, an Outstanding Role of Atom
Soure: Science Article by Kumar Pushkar, P.Darpan
Nanotechnology imitates the term umbrella which covers various areas of research dealing with object that are measured in nanometers. Nanometer (nm) is a billionth of a meter (10-9 metre) of a millimeter. Nanotechnology, simply, is the creation of functional materials, devices and systems through the control of matter on the nanometer scale.
To create things on nanometer scale, one has to be able to manipulate atoms individually. Atom is the smaller portion of an element that can take part in chemical reaction. So atoms are, undoubtedly, the building blocks of all matters in our universe. Nature has molecularly perfected the science of manufacturing matter. For instance, human bodies are assembled in a specific manner from millions of livingcells. Thus, cells become the nature’s nanomachines. Consumer goods that we by/use are made by pushing piles of together in an imprecise manner.
The challenge of nanotechnology is to place atoms precisely where we wish on a structure. Atoms and molecules stick together as they have complementary shapes that lock together, or changes that attract, i.e., a positively charged atom will stick to a negatively charged atom. As millions of these atoms are placed together by nanomachines, a specific product will begin to take shape. Some important steps to achieve nanotechnologically produced goods are as follows-
The goal of nanotechnology is to manipulate atoms individually and place them it in a pattern to a desired structure. Scientists must be able to manipulate individual atoms. This means that they will have to develop a technique to occupy single atom and move it on desired position. This process is repeated again and again. Similarly, 1990, IBM researchers showed that it is possible to manipulate single atom. They arranged 35 xenon atoms on the surface of nickel crystal with the help of instrument atomic force microscopy. These arranged atoms spelled out the letters ‘IBM’.
Nanoscopic machine are called assembles which can be programmed to manipulate atoms and molecules at will. In order to build enough assemblers to manufacture consumer goods, some nanomachines, called replicators, will be programmed to build more assemblers.
Assemblers and replicators will work together automatically to construct different products and will eventually replace all traditional labour methods. With the help of synthetic chemical methods we can create synthetic molecular motors, as in a so-called nenocar. This will vastly decrease manufacturing costs, thereby making consumer goods
plentiful, stronger and cheaper.
Modern Research
The following avenues of research could be considered subfields of nanotechnology-
(1) Colloid science has eastablished various materials having unique properties which are useful in nanotechnology, e.g., carbon nanotubes and nanorods.
(2) Nanomedicines are being developed.
(3) The bottom-up approaches of nanotechnology seek to arrange smaller components into more complex assemblies. For example, DNA nanotechnology utilizes the specificity of Watson-Crick base-pairing to from well-defined structures out of DNA and other nucleic acids.
(4) Top-down approaches seek to establish smaller devices by using larger one to direct their assembly. For example: (i) technologies descended from conventional solid-state silicon method for fabricating microprocessors are now capable of forming features smaller than 10 2 nm. (ii) Solid-state techniques can also be used to build devices known as nanoelectromechanical systems (NEMS), which are related to microelectromechanical systems (MEMS)
(5) The functional approaches of nanotechnology seek to develop components of a desired functionality without regard to how they might be assembled. For example, molecular electronics seek to created molecules with useful electronic properties, which could than be used as singlemolecule component in a nanoelectrical devices like rotaxane.
(6) With the help of synthetic chemical methods we can create synthetic molecular motors, as in a so-called nanocar.
Tools and Techniques
The atomic force microscope(AFT) and the scanning tunneling microscope(STM) are the two early versions of scanning probes that launched nanotechnology. Marvin Minsky in 1961and Calvin Quate in 1970 discovered scanning confocal microscope(SCM) and scanning acoustic microscope(SAM) respectively. These two microscopes made possible to see structures at the nanoscale. This led to the development of various techniques of nanolithography such as dip pen nanolithography, electron beam lithography and nanoimprint lithography. John R. Arthur, Alfred Y. Cho and A.C. Gossard developed and implemented molecular beam epitaxy (BME) as a research tool. Samples made by MBE were the key to the discovery of the fractional ‘quantum fluid’ for which the 1998 Nobel Prize in physics was awarded. The winners of this Nobel Prize were (are) Robert B. Larghlin, Horst L. Stoemer and Daniel C. Tusi.