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NanoTechnology

Written By: 

Ritu Dangi

 

From the gigantic universe to the little atom, Mother Nature with her amazing organization, has bestowed unique worth to everything, to the biggest and to the smallest too.

 
The big world of small, where an ant is a behemoth and thousands of atoms can fit on width of single human hair, You are in the startling world of Nanotechnology; ‘Nano’ it is tinier than the tiniest you can see and think!!
 
It is said that, ‘Small is Beautiful’, and today in the context of nanotechnology, Small is not only beautiful but stronger, incredible, inexpensive and mightier enough to change the pace of technology and way of living on earth.
 
Nanoscience and Nanotechnology are closely related terms. Nanoscience is the study and understanding of matter at ‘Nano-scale’, where unique properties allow never imagined applications and Nanotechnology is the way for manifestation of such novel applications. In other words, Nanotechnology is precise manipulation, control and use of matter at nano scale for design, characterization, and production for different applications, phenomenon or for specific technology. It is the engineering and technology conducted at ‘Nano’ scale.
 
So what actually this ‘Nano’ refers to?  In the International System of Units, the prefix "nano" (from Greek word nanos, meaning ‘dwarf’) means one-billionth, or 10-9; therefore one nanometer is one-billionth of a meter. For clear perspective of how small nano is, imagine if metre was earth then nanometre would be a marble!! Also a sheet of paper is about 100,000 nm thick and human hair is 75,000- 100,000 nm wide!!! An inch comprises of 25,400,000 nm and 1nm is about as long as your finger nail grows in one second!
 
An Image Showing Difference Among Micro, Nano, and Macro Inches
Fig. 1: An Image Showing Difference Among Micro, Nano, and Macro Inches

 

History:
The whole idea of Nanotechnology developed over a long period of time and finally geared up with the invention of Scanning Tunnelling microscope in 1981 which allowed to ‘see’ individual atoms! In 1959, the potential of nanotechnology was appropriately predicted by Sir Richard Feynman of CaliforniaInstitute of Technology in his lecture which is considered to be the first lecture on technology and engineering at the atomic scale, "There's Plenty of Room at the Bottom" at an American Physical Society meeting at Caltech. Feynman described a process by which the ability to manipulate individual atoms and molecules might be developed, using one set of precise tools to build and operate another proportionally smaller set, and so on down to the needed scale.
 

 

However, the term "nanotechnology" was coined by Professor Norio Taniguchi of Tokyo University of Science in a 1974 paper as follows: 'Nanotechnology' mainly consists of the processing of, separation, consolidation, and deformation of materials by one atom or by one molecule." The basic idea of this definition was popularized and explored in much more depth in the 1980's, when K. Eric Drexler promoted the technological significance of nano-scale phenomena and devices through speeches and the book “Engines of Creation: The Coming Era of Nanotechnology” (1986).

 

The discovery of quantum dots in 1981 followed by the discovery of Bucky balls in 1985 and Drexler’s Engines of Creation in 1986 marked the beginning of intense research in Nanotechnology leading to awe inspiring advancements.
 
In early 2000’s consumer products like lightweight nanotech automobile bumpers, golf ball, stiffer tennis rackets, nano-silver antibacterial socks, cosmetics etc appeared in market place. ‘National Nanotechnology Initiative’ (NNI), was launched at the same time by US govt to promote research and competitiveness of US in nanotechnology. 21st century is witnessing fast track research with all new inventions like nano cars, nano based lithium ion batteries and many more.
 

NanoTech. : Secret Power With-in

Nanotech. : Secret Power With-in

 

What is so special at nano scale that is allowing the nanotech magic to happen?

 

Matter such as gases, liquids, and solids can exhibit unusual physical, chemical, and biological properties at the nanoscale, differing in important ways from the properties of bulk materials and single atoms or molecules. Some nanostructure materials are stronger or have different magnetic properties compared to other forms or sizes or the same material. Others are better at conducting heat or electricity. They may become more chemically reactive or reflect light better or change colour as their size or structure is altered.
 
The causes of these drastic changes stem from the world of ‘Quantum Physics’. The bulk properties of any material are merely the average of all the quantum forces affecting all the atoms. As you make things smaller and smaller, you eventually reach a point where the averaging no longer works.
The properties of materials can be different at the nanoscale for two main reasons:
·         First, nanomaterials have a relatively larger surface area when compared to the same mass of material produced in a larger form. This can make materials more chemically reactive (in some cases materials that are inert in their larger form are reactive when produced in their nanoscale form), and affect their strength or electrical properties.
A Figure Showing Surface Area of a Nanomaterial
Fig. 2: A Figure Showing Surface Area of a Nanomaterial
 
·         Second, quantum effects can begin to dominate the behaviour of matter at the nanoscale - particularly at the lower end - affecting the optical, electrical and magnetic behaviour of materials. Materials can be produced that are nanoscale in one dimension (for example, very thin surface coatings), in two dimensions (for example, nanowires and nanotubes) or in all three dimensions (for example, nanoparticles)
 
The U.S. National Nanotechnology Initiative has large plans for nanotech. Mihail Roco, working with the organization, explains the group’s future plans by dividing their goals into four generations.
 
The first generation of nanotech is defined by passive structures that are created to carry out one specific task. Researchers are currently in this generation of the technology. The second generation is be defined by structures capable of multitasking. Researchers are currently entering this generation and hoping to further their abilities in the near future. The third generation will introduce systems composed of thousands of nanostructures. The fourth generation will be defined by nanosystems designed on the molecular level. These systems will work like living human or animal cells.
 
A Figure Defining Different Generations of a Nanotech
Fig. 3: A Figure Defining Different Generations of a Nanotech
Nanomaterial Fabrication:
What if reaching down the nano scale would be as easy as zooming out?? Unfortunately this is not practically possible yet. Fabrication of nanomaterial requires different approach.
 
 Top down approach works by miniaturizing strategy and involves lithographic patterning techniques. This is used for production of structures with long range orders. As component size is decreasing, physical limits of photolithography is becoming a problem for top down approach. Also, cost, heat dissipation problem in small geometries are adding on to the problems of top down approach. The solution to the limitations of top-down approach is its opposite Bottom-up approach. Bottom-up approach, inspired by nature, use chemical or physical forces operating at nanoscale to assemble basic units into a larger structure. Just like the nature’s way, Bottom-up approach uses concept of “Self-assembly”. Instead of taking away material to make structures, as done in Top-down approach, Bottom-up approach selectively adds atoms to create structures.
 
DNA Nanotechnology, classical chemical synthesis, dip pen nanolithography, Molecular self assembly are some of the techniques using Bottom-up approach.
 

Research & Applications

Nanotechnology: Research & Applications
Nanotechnology is not just a technology but a whole world within itself. Be it any field, nanotechnology has something to offer, for everything!!
Bio Medical & Health applications:
Nanotechnology is not less than a boon for Biomedical and health sector. It promises treatment to cancer, HIV like deadly diseases. Let’s see how nanotechnology can revolutionise this sector.
·         Effective Drug delivery: Nanotechnology has developed all-new methods of drug delivery that are far more efficient, safer and easier to An Image Representing Effectiveness of Nanotechnology in Drug Delivery
Fig. 4: An Image Representing Effectiveness of Nanotechnology in Drug Delivery
administer.                  
Most of the drugs developed are water insoluble and thus difficult to deliver at desired location. However, nanotech drugs consisting of nano sized particles can be easily delivered at precise locations, proper amount of dose and without affecting the nearby cells. For this drug delivery mechanism nano-sized drug carriers are needed. One approach is to use ‘Organic Dendrimers’. These are special type of polymeric molecules. They can be administered to deliver the drug to only some particular type of cell and at a triggered time. This approach is of great help in case of treatment of cancerous tumours.
The idea of “nano-robots” that can even be inhaled to fight harmful viruses and bacteria is based on the general approach of nanoparticle directed drug delivery.
·         Gold coated nanoparticles can carry antibodies on their surface so as to bind to specific tumour cells and reduce damage to other cells. They can also help in early stage detection of Alzheimer’s disease.
·         Molecular imaging for the early detection where sensitive biosensors constructed of nanoscale components can recognize genetic and molecular events and have reporting capabilities, thereby offering the potential to detect rare molecular signals associated with malignancy.
 
Electronics & Information technology applications:
Nanotechnology is well established in electronics & IT field of application. It has been used for many computing and electronics application and developed faster, An Image Representing Use of Nanotechnology in Electronic and IT Applications
Fig. 5: An Image Representing use of Nanotechnology in Electronic and IT Applications
 
smarter and portable systems. Certain components of chip transistors are gradually being reduced to a size of less than 20 nanometres, thus reaching to the quantum realm. With Moore’s law reaching its limits due to quantum effects such as ‘tunnelling’, scientists have started research in a radical new approach for data storage and information processing and developing a completely new type of electronics, which could produce a Quantum computer that could open up a totally new mathematical universe. 
     
Nanoscale transistors that are faster, more powerful, and increasingly energy-efficient; soon your computer’s entire memory may be stored on a single tiny chip. Magnetic random access memory (MRAM) enabled by nanometer scale magnetic tunnel junctions that can quickly and effectively save even encrypted data during a system shutdown or crash, enable resume play features, and gather vehicle accident data. Also, displays for many new TVs, laptop computers, cell phones, digital cameras, and other devices incorporate nanostructure polymer films known as organic light-emitting diodes, OLED screens offer brighter images in a flat format, as well as wider viewing angles, lighter weight, better picture density, lower power consumption, and longer lifetimes.
 
Carbon Nanotubes:
‘Fullerene’ (molecule consisting of carbon atoms only) when in the shape of sphere is known as ‘buck ball’, and when in form of cylindrical tube, is termed as An Image Representing the Structure of a Carbon Nanotube
Fig. 6: An Image Representing the Structure of a Carbon Nanotube
 
Carbon nanotube. Bucky balls have recently been detected in space and thus offering hopeful prospects in the search for exotic material. Carbon nanotube is nano sized tube (cylinder) of carbon atoms. They have noteworthy electronic, mechanical and chemical properties. They can exhibit both metallic and semiconductor behaviour, depending on the arrangement of their bonding. Research is going on to use carbon nanotubes for transistors and other electronics applications. They are even much stronger but lighter than steel. Constructing materials for space crafts, airplanes and other vehicles by carbon nanotubes can bring a drastic change in performance with better fuel efficiency and increased strength.
 
To assess the worth of this material it is enough to know that NASA has proposed to use carbon nanotubes for the highly ambitious project, “Space Elevator”, i.e. a lift between earth and space!!!
 

Nanotechnology Applications Contd..

Energy & Environment Applications:
With energy demands on an upward slope and at the same time the growing concern for a green environment, need of the hour is to have a clean, A Representational Image of Silicon Nanocrystals
Fig. 7: A Representational Image of Silicon Nanocrystals
 
affordable and renewable source of energy and without exception nanotechnology has an answer for this problem too!!
Development of silicon nanocrystals have made it possible to engineer solar cells capable of absorbing more energy. Moreover, nanostructure solar cells are cheaper to manufacture and easier to install, since they can use print-like manufacturing processes and can be made in flexible rolls rather than discrete panels. Newer research suggests that future solar converters might even be paintable. Not only this, researchers are developing wires containing carbon nanotubes to have much lower resistance than the high-tension wires currently used in the electric grid and thus reduce transmission power loss. Various nanoscience-based options are being pursued to convert waste heat in computers, automobiles, homes, power plants, etc., to usable electrical power.
 
Nanotechnology is helping to make environment cleaner too. Nanocrystals, nanofilters, nano sensors are being widely used for applications such as cleaning drinking water, removing materials that may cause harm to environment from crude oil etc. Moreover, nanotechnology based vehicles and machines consuming less fuel are helping too.
 
Applications in everyday life:
Nanotechnology has entered into your kitchen to keep the food fresher and safer for a long time. Nano-engineered materials in the food industry include nanocomposites in food containers to minimize carbon dioxide leakage out of carbonated beverages, or reduce oxygen inflow, moisture outflow, or the growth of bacteria. Nanosensors built into plastic packaging can warn against spoiled food. Nanosensors are being developed to detect salmonella, pesticides, and other contaminates on food before packaging and distribution.
 
Nanomaterial based cosmetics are not only provides greater clarity, absorption but take care of the skin too. In future, make-up, tattoos will be replaced with nanotreatments that alter skin and eye colour for a day, a week or even a month!!
 
Other than these, Molecular nanotechnology, Quantum dots and wells, Microelectromechanical systems (MEMS), Spintronics, Nanoengineering, Nanophotonics etc., the scope of nanotechnology seems endless.
 

Nanotechnology Future

Nanotechnology: An astounding Future!!!
The promising nanotechnology hides a novel future in the box. From the everyday products like clothes to the most sophisticated technical gadgets, everything will get high-tech with the bang of nanotechnology.
A Diagram Showcasing use of Nanotechnology in Every Aspect of Life in the Future
Fig. 8: A Diagram Showcasing Use of Nanotechnology in Every Aspect of Life in the Future
 
This picture is just a clip of the forthcoming big world of nanotechnology.
 
The ambitious vision of “Nano-bots”, i.e.  Robots of a size of only a few millionths of a millimetre, program-controlled and capable of creating something new and bigger from the provided raw materials conceals extraordinary possibilities.
 
But along with unlimited immense potential, some risk is present as well. Some nanoparticles may prove harmful too, in certain conditions e.g. if inhaled. Research is going on to find out such odd possibilities and to find the remedies too.
 
Dealing with the study at atomic level in physics, biology, chemistry, electronics, engineering and many more, Nanotechnology is offering plenty of applications in these myriad fields. It is replacing Quantity with Quality’. Truly it has the potential to bring revolution to every aspect of life.
The big leap of ‘nano’ is proving that Small is indeed beautiful!! Get ready to welcome an astonishing nano future.
Think future, Think small.