THOUSAND CDs
IN A WRIST WATCH
V.K.Subramanian*
Miniaturisation
is the buzz word today. Nanotechnology is not simply miniaturisation.
It is much more in frontier science, with its scope and application
limitless and mind boggling. "1000 compact discs in a wrist
watch",that is how Prof. CNR Rao, a noted scientist, terms
it.
Nanotechnology
is a term used for describing the creation and exploitation of
materials with structural features in between those of atoms and
bulk materials, with at least one dimension in the nanometer range
(1nm - 10-9 m). Properties of materials of nanometric dimensions
are significantly different from those of atoms or bulk materials.
A suitable control of the properties of nanometer-scalestructures
can lead to new science as well as new products, devices and technologies.
There has been
a tremendous growth of nanoscience and technology in the last
decade, primarily due to the availability of new methods of synthesis
of nanomaterials as well as tools of characterisation and manipualtion.
Several innovative methods of synthesizing nanoparticles and nanotubes
and their assemblies are now available. There is a better understanding
of size-dependent electrical, optical and magnetic properties
of individual nanostructures of semi-conductors, metals and other
materials. Besides the established techniques of electron microscopy,
crystallography and spectroscopy, scanning probe microscopes have
provided powerful tools for the study of nanostructures.
Novel methods
of fabrication concepts are being constantly discovered. Nanostructures
have also been ideal for computer simulation and modelling with
their size being sufficiently small to accommodate considerable
rigour in treatment. Ordered arrays or superlattices of nanocrystals
of metals and semiconductors have been prepared by several researchers.
Nanostructured polymers formed by the ordered self-assembly of
triblock copolymers and nanostructured high-strength materials
are other examples. Prototype circuits involving nanoparticles
and nanotubes for nanoelectronic devices have also been fabricated.
Quantum computing has made a good start and appropriate quantum
algorithms have been developed. Theory and computer simulation
are highly useful in understanding nanosystems.
Everything in
nanoscience is not new. Many existing technologies employ nanoscale
processes, catalysis and photography being well known examples.
Our capability to synthesize, organise and tailormake materials
at the nanoscale is, however, of very recent origin. The immediate
goal of science and technology of nanomaterials among other things
should be to fully master the synthesis of isolated nanostructures
(building blocks) and their ensembles and assemblies and desired
properties; explore and establish nanodevice concepts and systems
architecture; generate new classes of high performance materials,
including biology-inspired systems; connect nanoscience to molecular
electronics and biology and improve known tools while discovering
better tools of investigation of nanostructures.
Some of the potential
applications of nanotechnology of great societal and economic
impact lie in the production of novel materials and devices, nanoelectronics
and computer technology as well as in medicine and health care.
These wide-ranging applications may indeed usher in a new trend
in electronics, space, chemical energy and manufacturing industries.
Synthesis
Synthesis of
nanomaterials and assembling the nanostructures into ordered arrays
for rendering them functional and operational are crucial aspects
of nanoscience. The materials or structures include nanoparticles,
nanowires, nanotubes, nanostructured alloys and polymer, nanoporous
solids and DNA chips. Besides conventional tools of characterisation
such as X-ray, specialised instrumentation will be required. These
include sophisticated scanning probe microscopes, high resolution
electron microscopy and magnetic force microscopy.
Applications
Some of the important
applications and technologies include production of nanopowders
of ceramics and other materials, nanocomposites and other nanostructured
high strength materials, application of nanotubes for hydrogen
storage and other purposes, DNA chips and chips for chemical /
biochemical assays, gene targeting or drug targeting, nanoelctronics
and nanodevices.
The last one
is probably the most important difficult area. Applications of
this area include; new lasers, nanocomputers (based on nanotubes
and other materials) defect-free electronics for future molecular
computers, resonant tunneling devices, spintronics, combination
of biological motors with inorganic nanodevices and nanosensors.
The subject is
of great value and offers immense opportunities. It is a truly
interdisciplinary area encompassing physics, chemistry, biology,
materials and engineering. Interaction amongst technocrats with
different backgrounds will undoubtedly create new science and
in particular new materials with unforeseen technological possibilities.
While there is some effort in nanotechnology in a few academic
laboratories, there is a need to establish dedicated centres with
required infrastructure and experimental facilities. The subject
has caused excitement in the advanced as well as the developing
nations and is one area where international cooperation would
be highly fruitful. What is also noteworthy is that nanotechnology
will benefit not only the electronics industry, but also the chemical
and space industries, as well as the medicine and health care
sectors.
India is one
of the few leading countries of the world where work on nanotechnology
is progressing at a faster pace in a number of premier scientific
institutions. The Minister for Science and Technology, Dr. Murli
Manohar Joshi, a physicist by his own right, sums up, ‘Nanotechnology
could one day unravel the mystery of interconnectivity of the
whole universe’. (PIB Features)
*Information
Officer (S&T,Atomic Energy and Space), PIB, New Delhi
