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Nanotechnology and its applications
The concept “Nanotechnology” was first proposed by Richard Feynman on 29th December, 1959 in his talk entitled “There’s plenty of room at the bottom” at the California Institute of Technology. Deriving its name from the Greek word “dwarf” meaning small, nanotechnology is commonly defined as the combined art of science and technology of small things. National Nanotechnology Initiative in US has defined the scale range for nanotechnology as 1 to 100 nm.
Particles at their nanoscale behave extremely well by acquiring new properties due to increased surface area. For instance gold becomes a good catalyst for fuel cells and semiconductors at nanoscopic sizes. Nanotechnology is a positive approach for manipulating things at molecular or atomic level to create unique materials with enormous potential. It offers endless opportunities to design smaller, cheaper, and faster devices that can perform better at nanoscale [one nano-meter (one billionth of meter)] than the same materials being at large scale. Because of the wide range of potential applications it is common to use the term “nanotechnologies” or “nanoscale technologies.
Nanotechnology is highly interdisciplinary and has a wide range of applications in solid state physics, chemical engineering, electrical engineering, biophysics, materials science, biochemistry and biotechnology.
Some of the important applications of the nanotechnology are as follows:
Everyday materials and processes
Many benefits of nanotechnology depend on the fact that it is possible to tailor the structures of materials at extremely small scales to achieve specific properties, thus greatly extending the materials science toolkit. Using nanotechnology, materials can effectively be made stronger, lighter, more durable, more reactive, more sieve-like, or better electrical conductors, among many other traits. Many everyday commercial products are currently on the market and in daily use that rely on nanoscale materials and processes:
- Nanoscale additives to or surface treatments of fabrics can provide lightweight ballistic energy deflection in personal body armor, or can help them resist wrinkling, staining, and bacterial growth.
- Clear nanoscale films on eyeglasses, computer and camera displays, windows, and other surfaces can make them water- and residue-repellent, antireflective, self-cleaning, resistant to ultraviolet or infrared light, antifog, antimicrobial, scratch-resistant, or electrically conductive.
- Nanoscale materials are beginning to enable washable, durable “smart fabrics” equipped with flexible nanoscale sensors and electronics with capabilities for health monitoring, solar energy capture, and energy harvesting through movement.
- Lightweighting of cars, trucks, airplanes, boats, and space craft could lead to significant fuel savings. Nanoscale additives in polymer composite materials are being used in baseball bats, tennis rackets, bicycles, motorcycle helmets, automobile parts, luggage, and power tool housings, making them lightweight, stiff, durable, and resilient. Carbon nanotube sheets are now being produced for use in next-generation air vehicles. For example, the combination of light weight and conductivity makes them ideal for applications such as electromagnetic shielding and thermal management.
- Nano-bioengineering of enzymes is aiming to enable conversion of cellulose from wood chips, corn stalks, unfertilized perennial grasses, etc., into ethanol for fuel. Cellulosic nanomaterials have demonstrated potential applications in a wide array of industrial sectors, including electronics, construction, packaging, food, energy, health care, automotive, and defense. Cellulosic nanomaterials are projected to be less expensive than many other nanomaterials and, among other characteristics, tout an impressive strength-to-weight ratio.
- Nano-engineered materials in automotive products include high-power rechargeable battery systems; thermoelectric materials for temperature control; tires with lower rolling resistance; high-efficiency/low-cost sensors and electronics; thin-film smart solar panels; and fuel additives for cleaner exhaust and extended range.
- Nanostructured ceramic coatings exhibit much greater toughness than conventional wear-resistant coatings for machine parts. Nanotechnology-enabled lubricants and engine oils also significantly reduce wear and tear, which can significantly extend the lifetimes of moving parts in everything from power tools to industrial machinery.
- Nanoparticles are used increasingly in catalysis to boost chemical reactions. This reduces the quantity of catalytic materials necessary to produce desired results, saving money and reducing pollutants. Two big applications are in petroleum refining and in automotive catalytic converters.
- Nano-engineered materials make superior household products such as degreasers and stain removers; environmental sensors, air purifiers, and filters; antibacterial cleansers; and specialized paints and sealing products, such a self-cleaning house paints that resist dirt and marks.
- Nanoscale materials are also being incorporated into a variety of personal care products to improve performance. Nanoscale titanium dioxide and zinc oxide have been used for years in sunscreen to provide protection from the sun while appearing invisible on the skin.
Drug Delivery System
At present, 95% of all new therapeutic system have poor pharmokinetics and less developed biopharmaceutical properties. There is no such medicinal system that delivers drug and distribute therapeutically active drug molecules to the site of action or inflammation without any side effects. This problems are overcome by nanotechnology drug delivery system which possess multiple desirable attributes. Nanomedicine has a size such that it can be injected without occluding needles and capillaries which enables targeted drug delivery and medical imaging.Thus nanosized liposomes, micelles, nanoemulsions, nanogels are used for this purpose.
Nanotransmitters and nanosensors
Implantations of nanotransmitters and nanosensors within individuals have opened gates for monitoring and treating them at the microscopic level with the use of nanodevices. But this crosses traditional bounderies of care in the hospitals as persons can get the treatment done while siting in their homes . Pateients at home could have access to date transmitted from biochips which will moniter the diseases like hypercholesterolemia, alerting them when critical levels are obtained. Patients and clinicians would need to have throughout knowledge of device interfaces as all body metabolism will be regulated by these devices. The day may not be far than insurance deny us as money due to monitoring our health at cellular level in early stages. Nanotechnology will make us over dependent on devices. Inaccurate and errors with monitoring devices will be very challenging to detect. Advocates will be needed by everyone for safe and ethical use of nanomaterials. Monitoring methods would be needed to assure that devices are checked and caliberated within safety limits. Hence if these implications can be managed nanotechnology is the biggest boon to mankind.
Targeted drug therapies for treatment of cancer
If scientists can load their cancer-detecting gold nanoparticles with anticancer drugs, they could attack the cancer exactly where it lives. Such a treatment means fewer side effects and less medication used. Nanoparticles also carry the potential for targeted and time-release drugs. A potent dose of drugs could be delivered to a specific area but engineered to release over a planned period to ensure maximum effectiveness and the patient’s safety. These treatments aim to take advantage of the power of nanotechnology and the voracious tendencies of cancer cells, which feast on everything in sight, including drug-laden nanoparticles. One experiment of this type used modified bacteria cells that were 20 percent the size of normal cells. These cells were equipped with antibodies that latched onto cancer cells before releasing the anticancer drugs they contained.
From manufacturing to medicine to many types of scientific research, nanoparticles are now rather common, but some scientists have voiced concerns about their negative health effects. Nanoparticles’ small size allows them to infiltrate almost anywhere. That’s great for cancer treatment but potentially harmful to healthy cells and DNA. There are also questions about how to dispose of nanoparticles used in manufacturing or other processes. Special disposal techniques are needed to prevent harmful particles from ending up in the water supply or in the general environment, where they’d be impossible to track.
The researchers attach a protein (transferrin) that normally delivers iron to cells so that it delivers short interfering RNA (siRNA) molecules to cancer cells. The main function of RNA is protein synthesis within a cell. siRNA molecules are a class of RNA molecules that interfere with the expression of particular genes. The researchers encased the siRNA payload with sugar-containing polymers to create nanosized particles. Attaching transferrin molecules to the outer surface of a nanoparticle is one of the methods used to target nanoparticles to cancer cells. The nanoparticles will seek out cancer cells that overexpress the transferrin receptor.The gene-silencing siRNA nanoparticles are injected into the bloodstream and pass through blood vessels into the surrounding tissue. When the siRNA nanoparticles enter the tumor cells, acidic substances cause the nanoparticles to release the siRNA. The siRNA shuts down (silences) particular genes by leading to the degradation of the RNA transcripts of these genes throwing a monkey wrench into the cellular machinery and halting the multiplication of cancerous cells.To test their approach they tried it on laboratory mice with Ewing’s sarcoma tumors. They designed the siRNA to target a specific growthpromoting gene that is only active in Ewing’s sarcoma tumors, the EWS-FLI1 gene.
Their siRNA inhibits expression of EWS-FLI1, this shuts down part of the cellular machinery in the cancerous Ewing’s sarcoma cells so they should stop multiplying. This treatment technique should have fewer side-effects than traditionally administered chemotherapy (which affects all dividing cells in the body, both healthy and cancerous) since the nanoparticles are doubly targeted to the cells that overexpress the transferrin receptor and have the EWS-FLI1 gene—i.e., the tumor cells. The ingested siRNA nanoparticles only exert their effect in cells that contain the EWSFLI1 gene i.e., they have no effect when taken in by normal cells. After three consecutive days of treating 50 mice, they observed, “strong, but transient, inhibition of tumor growth. However, when used over longer durations (twice-weekly injections up to four weeks), the results were striking. Long-term treatments with this delivery system markedly inhibited tumor growth, with little or no tumor growth in many animals.
Electronics and IT applications
Nanotechnology has greatly contributed to major advances in computing and electronics, leading to faster, smaller, and more portable systems that can manage and store larger and larger amounts of information. These continuously evolving applications include:
- Transistors, the basic switches that enable all modern computing, have gotten smaller and smaller through nanotechnology. At the turn of the century, a typical transistor was 130 to 250 nanometers in size. In 2014, Intel created a 14 nanometer transistor, then IBM created the first seven nanometer transistor in 2015, and then Lawrence Berkeley National Lab demonstrated a one nanometer transistor in 2016! Smaller, faster, and better transistors may mean that soon your computer’s entire memory may be stored on a single tiny chip.
- Using magnetic random access memory (MRAM), computers will be able to “boot” almost instantly. MRAM is enabled by nanometer‐scale magnetic tunnel junctions and can quickly and effectively save data during a system shutdown or enable resume‐play features.
- Ultra-high definition displays and televisions are now being sold that use quantum dots to produce more vibrant colors while being more energy efficient.
- Flexible, bendable, foldable, rollable, and stretchable electronics are reaching into various sectors and are being integrated into a variety of products, including wearables, medical applications, aerospace applications, and the Internet of Things. Flexible electronics have been developed using, for example, semiconductor nanomembranes for applications in smartphone and e-reader displays. Other nanomaterials like graphene and cellulosic nanomaterials are being used for various types of flexible electronics to enable wearable and “tattoo” sensors, photovoltaics that can be sewn onto clothing, and electronic paper that can be rolled up. Making flat, flexible, lightweight, non-brittle, highly efficient electronics opens the door to countless smart products.
- Other computing and electronic products include Flash memory chips for smart phones and thumb drives; ultra-responsive hearing aids; antimicrobial/antibacterial coatings on keyboards and cell phone casings; conductive inks for printed electronics for RFID/smart cards/smart packaging; and flexible displays for e-book readers.
- Nanoparticle copper suspensions have been developed as a safer, cheaper, and more reliable alternative to lead-based solder and other hazardous materials commonly used to fuse electronics in the assembly process.
- Nanoparticle copper suspensions have been developed as a safer, cheaper, and more reliable alternative to lead-based solder and other hazardous materials commonly used to fuse electronics in the assembly process.
Nanotechnology is finding application in traditional energy sources and is greatly enhancing alternative energy approaches to help meet the world’s increasing energy demands. Many scientists are looking into ways to develop clean, affordable, and renewable energy sources, along with means to reduce energy consumption and lessen toxicity burdens on the environment:
- Nanotechnology is improving the efficiency of fuel production from raw petroleum materials through better catalysis. It is also enabling reduced fuel consumption in vehicles and power plants through higher-efficiency combustion and decreased friction.
- Nanotechnology is also being applied to oil and gas extraction through, for example, the use of nanotechnology-enabled gas lift valves in offshore operations or the use of nanoparticles to detect microscopic down-well oil pipeline fractures.
- Researchers are investigating carbon nanotube “scrubbers” and membranes to separate carbon dioxide from power plant exhaust.
- Researchers are developing wires containing carbon nanotubes that will have much lower resistance than the high-tension wires currently used in the electric grid, thus reducing transmission power loss.
- Nanotechnology can be incorporated into solar panels to convert sunlight to electricity more efficiently, promising inexpensive solar power in the future. Nanostructured solar cells could be 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.”
- Nanotechnology is already being used to develop many new kinds of batteries that are quicker-charging, more efficient, lighter weight, have a higher power density, and hold electrical charge longer.
- An epoxy containing carbon nanotubes is being used to make windmill blades that are longer, stronger, and lighter-weight than other blades to increase the amount of electricity that windmills can generate.
- In the area of energy harvesting, researchers are developing thin-film solar electric panels that can be fitted onto computer cases and flexible piezoelectric nanowires woven into clothing to generate usable energy on the go from light, friction, and/or body heat to power mobile electronic devices. Similarly, various nanoscience-based options are being pursued to convert waste heat in computers, automobiles, homes, power plants, etc., to usable electrical power.
- Energy efficiency and energy saving products are increasing in number and types of application. In addition to those noted above, nanotechnology is enabling more efficient lighting systems; lighter and stronger vehicle chassis materials for the transportation sector; lower energy consumption in advanced electronics; and light-responsive smart coatings for glass.
In addition to the ways that nanotechnology can help improve energy efficiency, there are also many ways that it can help detect and clean up environmental contaminants:
- Nanotechnology could help meet the need for affordable, clean drinking water through rapid, low-cost detection and treatment of impurities in water.
- Engineers have developed a thin film membrane with nanopores for energy-efficient desalination. This molybdenum disulphide (MoS2) membrane filtered two to five times more water than current conventional filters.
- Nanoparticles are being developed to clean industrial water pollutants in ground water through chemical reactions that render the pollutants harmless. This process would cost less than methods that require pumping the water out of the ground for treatment.
- Researchers have developed a nanofabric “paper towel” woven from tiny wires of potassium manganese oxide that can absorb 20 times its weight in oil for cleanup applications. Researchers have also placed magnetic water-repellent nanoparticles in oil spills and used magnets to mechanically remove the oil from the water.
- Many airplane cabin and other types of air filters are nanotechnology-based filters that allow “mechanical filtration,” in which the fiber material creates nanoscale pores that trap particles larger than the size of the pores. The filters also may contain charcoal layers that remove odors.
- Nanotechnology-enabled sensors and solutions are now able to detect and identify chemical or biological agents in the air and soil with much higher sensitivity than ever before. Researchers are investigating particles such as self-assembled monolayers on mesoporous supports (SAMMS™), dendrimers, and carbon nanotubes to determine how to apply their unique chemical and physical properties for various kinds of toxic site remediation. Another sensor has been developed by NASA as a smartphone extension that firefighters can use to monitor air quality around fires.
Future transportation benefits
Nanotechnology offers the promise of developing multifunctional materials that will contribute to building and maintaining lighter, safer, smarter, and more efficient vehicles, aircraft, spacecraft, and ships. In addition, nanotechnology offers various means to improve the transportation infrastructure:
- As discussed above, nano-engineered materials in automotive products include polymer nanocomposites structural parts; high-power rechargeable battery systems; thermoelectric materials for temperature control; lower rolling-resistance tires; high-efficiency/low-cost sensors and electronics; thin-film smart solar panels; and fuel additives and improved catalytic converters for cleaner exhaust and extended range. Nano-engineering of aluminum, steel, asphalt, concrete and other cementitious materials, and their recycled forms offers great promise in terms of improving the performance, resiliency, and longevity of highway and transportation infrastructure components while reducing their life cycle cost. New systems may incorporate innovative capabilities into traditional infrastructure materials, such as self-repairing structures or the ability to generate or transmit energy.
- Nanoscale sensors and devices may provide cost-effective continuous monitoring of the structural integrity and performance of bridges, tunnels, rails, parking structures, and pavements over time. Nanoscale sensors, communications devices, and other innovations enabled by nanoelectronics can also support an enhanced transportation infrastructure that can communicate with vehicle-based systems to help drivers maintain lane position, avoid collisions, adjust travel routes to avoid congestion, and improve drivers’ interfaces to onboard electronics.
- “Game changing” benefits from the use of nanotechnology-enabled lightweight, high-strength materials would apply to almost any transportation vehicle. For example, it has been estimated that reducing the weight of a commercial jet aircraft by 20 percent could reduce its fuel consumption by as much as 15 percent. A preliminary analysis performed for NASA has indicated that the development and use of advanced nanomaterials with twice the strength of conventional composites would reduce the gross weight of a launch vehicle by as much as 63 percent. Not only could this save a significant amount of energy needed to launch spacecraft into orbit, but it would also enable the development of single stage to orbit launch vehicles, further reducing launch costs, increasing mission reliability, and opening the door to alternative propulsion concepts.
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