Girish N. Chaple Tushar P.Upalanchiwar 6th Semister B.E 6thSemisterB.E Department Of Electronics Engineering Department Of Electronics Engineering B.D.C.O.E Sevagram,Wardha B.D.C.O.E Sevagram,Wardha [email protected] [email protected]

Abstract – Nanotechnology is technic to design, characterization, production, and application of structures, devices, and systems by controlled manipulation of size and shape at the nanometer scale (nearly100nm) that produces structures, devices, and systems with at least one superior characteristic or property. with two different approaches, bottom-up and top- down. Atomic force microscopes (AFM) and scanning tunneling microscopes (STM) are basic tools use to look at surfaces and to move atoms around. nanotechnology use to improve existing products by creating smaller components and better performance materials with vast a range of areas of physics (such as , and ),chemistry (nanofiltration, nanocomposites), biology (bionanoscience, nanobiosensors ) etc.Nanotechnology has wide range of applications in medicines, energy, communication,cosmatics, aerospace,environment.

Keywords – Nanomaterials, Nanoparticles, Nanorobotics, Nanoelectronics, Nanomedicines.

I. Basic concept of Nanotechnology

Nanotechnology Is study of the controlling of matter on an atomic and molecular scale. Generally nanotechnology deals with structures of the size 100 nanometers or smaller in at least one dimension.[1]

1meter=100cm 1cm=10milimeter 1milimeter=1000micrometer 1micrometer=1000nanometer & 1meter=10-9 By comparison, typical carbon-carbon bond lengths, or the spacing between these atoms in a molecule, are in the range 0.12–0.15 nm, and a DNA double-helix has a diameter around 2 nm. Nanotechnology is exciting emerging & technological field. It is all about building things atom by atom & molecule by molecule. Manufacturing products made from an atom, the property of those products depends on how those atoms are arranged. Goal of this technology is to make tiny devices called ‘Nanomachines’.

II. Approaches & tools use in Nanotechnology

Two main approaches are used in nanotechnology are the "bottom-up" approach & “top-down”. Bottom-up - approach, materials and devices are built from molecular components which assemble themselves chemically by principles of molecular recognition. Top-down - approach, nano-objects are constructed from larger entities without atomic-level control.[2] Top-down refers to making nanoscale structures by machining and etching techniques, whereas bottom-up, or "molecular nanotechnology," applies to building organic and inorganic structures atom-by-atom, or molecule-by-molecule. The atomic force microscope (AFM) and the Scanning Tunneling Microscope (STM) are two early versions of scanning probes that launched nanotechnology. There are other types of scanning probe microscopy, all flowing from the ideas of the scanning confocal microscope developed by Marvin Minsky in 1961 and the Scanning Acoustic Microscope (SAM) developed by Calvin Quate and coworkers Typical AFM setup in the 1970s, that made it possible to see structures at the nanoscale.[3]

III. Nanomaterials [A] Fullerene – A fullerene is any molecule composed entirely of carbon, in the form of a hollow sphere, ellipsoid, or tube. Spherical fullerenes are also called buckyballs, and cylindrical ones are called carbon nanotubes or buckytubes.[4] fig. Bucky Ball consists of 60 carbon atoms [B] – Carbon Nanotubes are Single-Walled, Double Walled and Multi-Walled black nano scale cylindrical tubes of graphitic carbon with numerous application. single-walled nanotubes (SWNT) have a diameter of close to 1 nanometer. fig.Carbon nanotube Carbon Nanotubes are the stiffest and strongest known fibers and have unique electrical properties. .Carbon nanotubes can behave like a conductive metallic or depending on their structure, which is useful for nanoscale electronic devices and in electrically conductive films in coatings, plastics, , nanofiber and in certain bioscience applications. Recently, carbon nanotubes have been demonstrated to create the "darkest" known material absorbing all wavelengths or "colors" of light which will prove useful in solar and electronic applications.[4]

IV. Nanoparticles

In nanotechnology, a particle is defined as a small object that behaves as a whole unit in terms of its transport and properties. It is further classified according to size: in terms of diameter, fine particles cover a range between 100 and 2500 fig. Colloidal crystal composed of nanometers, while ultrafine particles in amorphous hydrated colloidal silica range of 1 and 100 nanometers. (particle diameter 600 nm) Iron Nanoparticles, Iron Oxide Nanopowder, Cobalt Nanoparticles, and several other elemental nanoparticles and alloys form a group of "Magnetic Nanoparticles" with promising application in medical treatment of cancer, magnetic storage and magnetic resonance imaging (MRI). deposition of Nanoparticle quantum dots on the polycrystalline silicon substrate of a photovoltaic (solar) cell increases voltage output as much as 60% by fluorescing the incoming light prior to capture. Zinc Oxide nanoparticles , zinc nanoparticles and silver nanoparticles , are used for many applications, including as an anti-microbial, anti- bacterial, anti-biotic and anti-fungal agents when incorporated in coatings, fibers, polymers, first aid bandages, plastics, soap and textiles.[4]

V. Nanorobotics

Nanorobotics is the technology of creating machines or robots at or close to the . microscopic scale of a nanometer (10−9 meters). More specifically, nanorobotics refers to the still largely hypothetical discipline of designing and building nanorobots, devices ranging in size from 0.1-10 micrometers and constructed of nanoscale or molecular components. The names nanobots, nanoids, nanites or nanomites have also been used to describe Fig.Imagenary-Nanorobot these hypothetical devices. An example is a sensor having a switch approximately 1.5 nanometers across, capable of counting specific molecules in a chemical sample. where they might be used to identify cancer cells and destroy them. Another potential application is the detection of toxic chemicals, and the measurement of their concentrations, in the environment.[4]

VI. Nanoelectronics

[A] Moleculer Electronics –

Molecular electronics is that branch of nanotechology, which deals with the study and application of molecular building blocks for the fabrication of electronic components,both passive and active. area is the use of molecular building blocks for the fabrication of electronic components, both passive (e.g. resistive wires) and active (e.g. ). molecular scale electronics focuses on single-molecule applications

[B] –

Nanolithography is that branch of nanotechnology,which deals with the study and application of fabrication of nanoscale structures like semiconductor circuits. Nanolithography refers to the fabrication of nanometer-scale structures, meaning patterns with at least one lateral dimension between the size of an individual atom and approximately 100 nm. Nanolithography is used during the fabrication of leading-edge semiconductor integrated circuits (nanocircuitry) or nanoelectromechanical systems (NEMS). The most common nanolithographic technique is Electron-Beam Direct-Write Lithography (EBDW), the use of a beam of electrons to produce a pattern — typically in a polymeric resist such as PMMA.[4]

VII. Nanomedicines

[A] Nanotoxicology –

Nanotoxicology is a branch of bionanoscience which deals with the study and application of toxicity of nanomaterials. Nanomaterials, even when made of inert elements like , become highly active at nanometer dimensions. Nanotoxicological studies are intended to determine whether and to what extent these properties may pose a threat to the environment and to human beings. For instance, Diesel nanoparticles have been found to damage the cardiovascular system in a mouse model. Nanotoxicology is the study of the toxicity of nanomaterials. Because of quantum size effects and large surface area, nanomaterials have unique properties compared with their larger counterparts.

[B] –

Nanosensors are any biological, chemical, or sugery sensory points used to convey information about nanoparticles to the macroscopic world. Medicinal uses of mainly revolve around the potential of nanosensors to accurately identify particular cells or places in the body in need. By measuring changes in volume, concentration, displacement and velocity, gravitational, electrical, and magnetic forces, pressure, or temperature of cells in a body, nanosensors may be able to distinguish between and recognize certain cells, most notably those of cancer, at the molecular level in order to deliver medicine or monitor development to specific places in the body. In addition, they may be able to detect macroscopic variations from outside the body and communicate these changes to other nanoproducts working within the body. One example of nanosensors involves using the fluorescence properties of cadmium selenide quantum dots as sensors to uncover tumors within the body.[4]

VIII. Future Of Nanotechnology –

IX. Applications of Nanotechnology –

1.Increasing the efficiency of energy production – Thin film deposition of Silicon Nanoparticle quantum dots on the polycrystalline silicon substrate of a photovoltaic cell increases voltage output as much as 60% by fluorescing the incoming light prior to capture. 2.cosmatics – One field of application is in sunscreens. The traditional chemical UV protection approach suffers from its poor long-term stability. A sunscreen based on mineral nanoparticles such as titanium dioxide offer several advantages. Titanium oxide nanoparticles have a comparable UV protection property as the bulk material.

3.Textiles – The use of engineered nanofibers already makes clothes water- and stain- repellent or wrinkle-free. Textiles with a nanotechnological finish can be washed less frequently and at lower temperature..

4.Novel optoeletronic devices – Two promising examples are photonic crystals and quantum dots. They offer a selectable band gap for the propagation of a certain wavelength, thus they resemble a semiconductor, but for light or photons instead of electrons. Quantum dot lasers are cheaper and offer a higher beam quality than conventional laser diodes.

5.Memory storage – Electronic memory designs in the past have largely relied on the formation of transistors. However, research into crossbar switch based electronics have offered an alternative using reconfigurable interconnections between vertical and horizontal wiring arrays to create ultra high density memories.

6.Tissue engineering – Nanotechnology can help to reproduce or to repair damaged tissue. “Tissue engineering” makes use of artificially stimulated cell proliferation by using suitable nanomaterial-based scaffolds and growth factors. Tissue engineering might replace today’s conventional treatments like organ transplants or artificial implants. Advanced forms of tissue engineering may lead to life extension.[5]

X. Conclusion

Developments in nanotechnology are some of the most important scientifc developments in recent years. despite views that nanotechnology is a far-fetched idea with no near-term applications, nanoparticles, nanopowders and nanotubes already play a significant role in industry, environmental remediation, medicine, science and even in the house “The best way to predict the future is to invent it "

XI. References

[1] "Nanotechnology Basics: For Students [4] "Nanotechnology Basics: For Students and Other Learners." Center for and Other Learners." Center for Responsible Nanotechnology. World Care. Responsible Nanotechnology. World Care. 11 Nov. 2008. 11 Nov. 2008. [2] Rodgers, P. (2006). "Nanoelectronics: [5] "Applications/Products". National Single file". Nature Nanotechnology. Nanotechnology Initiative. doi:10.1038/nnano.2006. http://www.nano.gov/html/facts/appsprod. [3] "Nanotechnology Introduction Pages". html. Nanotech-now.com