Nanotechnology: Understanding the Science of the Small
With so many emerging technologies in the world, what exactly makes nanotechnology stand out as one of the most prominent and promising new technologies? The answer, as you’ll soon find out, is its practically endless applications, from solar panels and electronics, to healthcare and foods. Nanotechnology is present in our everyday lives, often without most of us even knowing it, and it is in a position where it will only become increasingly integrated into our lives as a revolutionary technology that will affect major industries around the world.
What is Nanotechnology?
Nanotechnology is known as the science of the small. The word “nano” is derived from the Greek word which means “dwarf” (nanotechnology effectively meaning “small technology”). It is the control of matter on an atomic and molecular level in the scale of less than 100 nanometers, and the fabrication of devices within that particular size range. Nanotechnology involves the imaging, measuring, modeling, and manipulating of matter at this nanoscale range.
One nanometer is equivalent to 1 billionth of a meter and there are 25,400,000 nanometers in an inch. Look at a single strand of your hair; a nanometer is 100 000 times smaller than that one strand of hair!
When you break down an object into the scale of nanometers, the entire physical and chemical properties of that matter change. Materials that are broken down to the nanoscale can have enhanced properties such as lighter weight, greater strength, increased control of light spectrum, and greater chemical reactivity compared to their larger scale counterparts.
History of Nanotechnology
Despite the fact that nanotechnology is a relatively recent development in scientific research, the development of its central concepts occurred over a longer period of time.
While nanoparticles are often associated with modern science, they were utilized as far back as the ninth century in Mesopotamia by artisans to create a glittering effect on surfaces of pots.
Pottery from the Middle Ages and Renaissance often retains a distinct gold- or copper-colored metallic glitter. Artisans added a metallic film to the transparent surface of a glazing. This film contained silver and copper nanoparticles dispersed homogeneously throughout the glass-like matrix of the ceramic glaze to achieve high luster.
Michael Faraday was interested in investigating the interaction of light and matter. In 1875, he was the first to discover “ruby” colloidal gold, which demonstrated that nanostructured gold under certain lighting conditions produced different colored solutions.
By 1959, Richard Feynman from the California Institute of Technology gave what is considered to be the first lecture on nanotechnology and engineering at the atomic scale titled, “There’s Plenty of Room at the Bottom”. Feynman’s famous talk on top-down nanotechnology considered a number of interesting ramifications of the general ability to manipulate matter on an atomic scale and the possible future applications of this, such as the fact that we could make nanoscale machines to “arrange the atoms the way we want” and do chemical synthesis by mechanical manipulation.
The term “nano-technology” was later coined by a Tokyo Science University Professor named Norio Taniguchi in 1974. His definition of this technology was, “Nano-technology’ mainly consists of the processing of, separation, consolidation, and deformation of materials by one atom or one molecule.”
The great emergence of nanotechnology occurred in the 1980s, caused by the convergence and advancements of inventions such as the scanning tunneling microscope in 1981 that allowed scientists to view the atomic and molecular details of surfaces. As other technologies such as the STM were created and developed, it became easier to view and work with nanotechnology, which eventually led to the formation of companies and entire industries centered around nanotechnology.
Early nanotechnology companies began to operate in the 1990s and by the early 2000s, the field of nanotechnology was subject to growing public awareness and controversy. There were many debates about its potential implications and the feasibility of its applications, however, the early 2000s also gave rise to the beginnings of commercial applications of nanotechnology.
Recent years have given rise to many amazing breakthroughs in nanotechnology and new applications are being discovered every day that affect every industry around the world.
Current Applications of Nanotechnology
There are many different applications of nanotechnology, as it is known for its potential to increase the efficiency of energy consumption, help clean the environment, solve major health problems, and massively increase manufacturing production at significantly reduced costs. Nanotechnology products are smaller, cheaper, and lighter, yet more functional then conventional products and technologies. These products will also require less energy and fewer raw materials to manufacture.
Some of the main applications currently being focused on in the field of nanotechnology are:
- solar cells
- carbon capture
- nanotech and food
Nanomaterials are materials or chemical substances that have been manufactured and used at a microscopic scale. They are materials that possess at least one external dimension that measures from 1–100nm. There are four different main types of nanomaterials:
- Carbon-Based Materials: composed mainly of carbon and usually takes the form of hollow spheres or tube shapes. Carbon-based nanomaterials can have the potential to improve films and coatings, they can create stronger and lighter materials, and can be used in electronics (known as nanoelectronics).
- Metal-Based Materials: can act as a good semiconductor and includes quantum dots, nanogold, nanosilver, and metal oxides (such as titanium dioxide).
- Dendrimers: nanosized polymers that are usually used for specific chemical functions and can also be important in catalysis.
- Composites: made by combining certain nanoparticles with other nanoparticles/nanomaterials. This nanomaterial can be used to enhance the mechanical, thermal, barrier, and flame-retardant properties in products such as auto parts and packaging materials.
The top-down approach is a method of constructing nanotechnology that uses microfabrication techniques like photolithography to downscale the material. The top-down approach would create a tiny computer chip by carving away at the larger material like a sculptor to create the nano-sized features of the chip. This approach never deals with the atomic level of matter. The top-down method is currently being used to manufacture not only computer chips, but other products that you use in your every day life.
The bottom-up approach is more of a theoretical method of engineering nanomaterials that involves assembling atoms and molecules into the desired nanostructure. Constructing something such as an extremely tiny computer chip would use nanotechnology in a bottom-up approach to assemble the chip atom by atom and place each type of atom in a specific location to build the circuit.
One form of the bottom-up approach is known as self-assembly, which involves creating conditions so that the desired atoms and molecules arrange themselves in a specific way to create a material without any external manipulation.
Nanosensors are devices that operate at the nanoscale to measure physical quantities, and then convert these to signals that can be detected and analyzed. They essentially work the same way as conventional sensors, however nanosensors use nanomaterials as their active sensing element. There are two main types of nanosensors:
- chemical nanosensors: these nanosensors detect chemicals by measuring the change in electrical conductivity of the nanomaterial once the substance has been identified.
- mechanical nanosensors: this type of nanosensor also works by detecting changes in electrical conductivity, however, the mechanism is different and the nanomaterials that are used as mechanical nanosensors change their electrical conductivity when the material is physically manipulated.
Nanomedicine is the application of nanotechnologies in the field of healthcare. Nanomedicine typically involves the use of nanoparticles to improve the behavior of drug substances and delivery. It can also include a wide range of applications such as biosensors, tissue engineering, diagnostic devices, and more.
Most research into nanomedicine has focused on the development of biosensors to aid in diagnostics and ways to administer vaccines, medications, and gene therapy. This includes the development of nanocapsules to aid in cancer treatment.
Nanotechnology can effectively diagnose, treat, and prevent various diseases. Medications can therefore be more efficiently delivered to the site of action using nanotechnology, which results in improved healthy outcomes with less medication.
A nanofilter uses a membrane filtration process with nanometer sized through-pores (a pore size of around 0.001 micron) to purify and desalinate water. It is often used on water such as surface water and fresh groundwater to soften the water with polyvalent cation removal and remove most organic molecules, viruses, natural organic matter and a wide variety of salts/salt ions that are present within the water. The membranes used are usually created by polymer thin films and are typically made from polyethylene terephthalate and other similar materials.
In more recent years, the use of nanofilters has extended into other industries aside from just water purification, such as in milk and juice production. The application for nanofiltration membranes have also extended into new areas that include pharmaceuticals, fine chemicals, and flavor and fragrance industries due to the development of solvent-stable membranes.
Nanophotonics, also known as nano-optics, is the study of the behavior of light on the nanometer scale, and the interaction of light with nanometer-sized objects. Nanophotonics can often include certain metallic components that focus and transport light through surface plasmon polaritons.
The field of nanophotonics is associated with specific breakthroughs using light in new technologies such as silicon-based semiconductors, by improving the speed and performance.
Even within just the field of nanophotonics, nanotech can enable different technologies with the potential to impact numerous application domains such as the environment, healthcare, military, transport, manufacturing, and energy.
Nanotechnology can also be implemented by using nanoparticles in the manufacturing of solar cells. The use of nanotechnology in solar cells:
- reduces manufacturing costs due to the low temperature process it uses instead of the high temperature vacuum deposition that is used to manufacture conventional solar cells.
- reduces the installation costs by producing flexible rolls instead of the rigid crystalline panels of conventional cells. While some nano solar cells are not as efficient as traditional cells, their lower cost more than makes up for it.
- newer versions using quantum dots in solar cells should be able to both lower the cost and reach higher efficiency levels compared to conventional solar cells.
Technology can be employed at the nanoscale in batteries by either having the batteries nano in size or using nanotechnology in a macro scale battery. “Nano batteries” can increase the available power from a battery and decrease the amount time it requires to recharge a battery. These benefits can be achieved by coating the surface of a battery’s electrode with nanoparticles, which increases the surface area of the electrode to allow more current to flow between the electrode and more current to flow between the electrode and chemicals inside the battery. By using this technique:
- the efficiency of hybrid vehicles could increase by significantly reducing the weight of batteries needed to provide the adequate power to run the vehicle.
- there would be an increase the shelf life of a battery through using nanomaterials to separate liquids in the battery from the solid electrodes when there is no current draw on the battery, which prevents the low level discharge that occurs in a typical battery.
Nanotechnology can help capture carbon dioxide created during industrial processes to keep it out of the air supply, store it and even reuse the CO2 as fuel. The first step of this process is capturing the carbon dioxide that is produced by power plants, utilizing these different methods:
- nanoporous membranes to remove carbon dioxide from power plant smokestacks.
- development of nanomaterials to trap and store or transport carbon dioxide.
After the carbon dioxide is captured, it can be pumped underground and stored in layers of permeable rock so that it can’t contaminate the air. It can also be pumped into oil fields to boost the recovery of oil. This can happen because the increasing pressure in the field and the slowing viscosity of the oil makes it flow more easily.
Nanotech + Food
Nanotechnology can be implemented in packaging materials, farming practices, food processing and also in foods themselves. Nanotech has been used to:
- enhance delivery of food ingredients to target sites
- increase flavor
- inhibit bacterial growth
- extend product shelf life
- improve food safety
Nanotech can be used in food packaging to allow for greater food protection by creating stronger mechanical and thermal capabilities, as well as by increasing antibacterial properties. Food packaging that has been nano-engineered provides biodegradable protection against gas penetration, leakage, and pathogen entrance into foods. For example, silver is a well known anti-microbial agent that has been utilized for these properties in nano-engineered food packaging.
“Nanofoods” is also another application, in which nanotech can be used to enhance the colour, flavor, and size of different foods. Food and water are naturally made up of particles on the nanometer scale, which makes it easier for engineered nanoparticles to penetrate these products based on their similar properties.
Nanoparticles can be used to make a difference through their different sizes and unique shapes- the smaller the particle, the faster it will reach our taste buds to satisfy what we are looking for. It can also increase the amount of organic nutrients added within the meal at a smaller size.
Security and Defense
Military research for nanotechnology looks into how to improve medical and casualty care for soldiers, as well as how to produce lightweight, strong and multi-functional materials to use in clothing, which would allow for better protection and enhanced connectivity; improved body armor is a major focus for military in nanotechnology.
Another interesting application that is still being researched is nanotechnology in cloaking. This is done through using metamaterials. This material would control the portion of the electromagnetic spectrum that we can see so that when light streams past an object, it goes around instead of through the object. The observer would never even know that the object was there and thus create an invisibility affect on the object.
Hydrophobic nanotechnology has the ability to repel water and all liquids. Any liquid poured on a material with a hydrophobic coating just beads and rolls off the surface instead of soaking into the material like it normally would. Hydrophobic coatings can be used to enhance fabrics by providing benefits such as:
- improving flame-resistance
- keeping colors richer for longer
- preventing sun damage
- providing a level of scratch resistance that makes the fabric more durable.
- certain types of hydrophobic nanotechnologies that can also have anti-bacterial properties.
Liquids that are spilled onto hydrophobic nanotechnology do not get absorbed or stain the fabric like they would normally do to regular clothing.
Hydrophilic nanotechnology is the opposite of hydrophobic- it absorbs the water or liquids and has the tendency to mix or dissolve in water. One of the many applications this technology can be used for is self-cleaning glass.
For example, a company called Pilkington has created a product that they call Activ Glass. This product uses nanoparticles to make the glass hydrophilic and photocatalytic- meaning when UV radiation comes from the light to hit the glass, the nanoparticles become energized, beginning to break down and loosen organic molecules on the glass. Hydrophilic means that the water spreads across the glass evenly when it comes in contact with the glass, which is what helps easily wash the glass clean.
Graphene and Carbon Nanotubes (CNT)
Graphene is an allotrope of carbon, which consists of a singular layer of atoms that all lie in a plain together arranged in a 2D hexagonal lattice structure. It is one of the most versatile and strongest metals on earth and its properties include:
- extremely high strength
- lightweight material
- great flexibility
- high thermal and electrical conductivity
By taking a sheet of graphene and rolling it into the shape of a cylinder, you get a carbon nanotube. Carbon nanotubes currently have the highest tensile strength of any fibrous material known in the world. Carbon nanotubes can be manufactured using metal catalyzed polymerization method, an example of using the bottom-up approach nanotechnology.
The Implications of Nanotechnology
- Environmental concerns: there are several concerns about potential routes for nanomaterials entering into and damaging the environment. Exposure of the aquatic environment to nanomaterials can also be a widespread risk. This could have similar effects as the exposure routes for regular chemicals. For example, the production of wastes (liquid, solid, or airborne), release from products during the product life, and during the waste cycle, which can all influence and impact the environment.
- Human Exposure: nanomaterials can come in direct contact with humans by using products such as in food, cosmetic, and medical applications. Indirect contact can also come from the unintended exposure of workers during the manufacturing of nanomaterials and the general public due to the accumulating nanomaterial in the environment. The effects of certain nanoparticles are still unknown and more research needs to be done on their toxicity and potential effects on humans.
- Nanotechnology in the Wrong Hands: as with all emerging technologies, nanotech has the capability of being used for terrible applications and unforeseen uses. The growing availability of this technology, such as nanobots and cloaking, would eventually lead to their use for criminal activity. As this technology is becoming more widespread, there will be an enormous challenge to regulate its uses and future applications.
The Future of Nanotechnology
While there are many applications of nanotechnology being used today, there are still so many possibilities for this technology and opportunities to expand on ideas or applications in the future, many that we may not have even thought about yet. Nanotechnology is an exciting field full of possibility and it is already on its way to revolutionizing the world.
- Nanotechnology is the control of matter on an atomic and molecular level in the scale of less than 100 nanometers, and the fabrication of devices within that particular size range.
- When you break down an object into the scale of nanometers, the entire physical and chemical properties of that matter change, and it can gain enhanced properties.
- The use of nanotechnology can date back as far back as the 9th century, however it developed over a long period of time until its applications began to be commercialized in the early 2000s.
- Nanotechnology has many different applications such as nanomaterials, nanosensors, nanomedicine, nanofilters, nanoelectronics, nanophotonics, solar cells, batteries, carbon capture, military/security, and in foods.
- Graphene is a an allotrope of carbon, which consists of just a single layer of atoms arranged in a honeycomb structure.
- Carbon nanotubes are tubes that are made of carbon with diameters typically that are typically measured in nanometers.
- There is some controversy and debates based on the implications of nanotechnology due to human exposure to toxic nanoparticles and the environmental concerns that it may pose.
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