What Is Nanotechnology, and How Does It Work?

Key Points

• Nanotechnology is set to completely switch up the way we develop and apply technology in all aspects of our daily lives.
• Nanomaterials exhibit unique properties due to their small size and quantum effects.
• There are four main types of nanomaterials: carbon-based, metal-based, dendrimers, and nanocomposites.
• Nanotechnology has a wide range of applications, including drug delivery, medical diagnosis, lighting, imaging, and water purification.
• The future of nanotechnology holds even more advanced uses, but safety concerns must be addressed.

In the tech space, it feels like we can’t go more than 5 minutes these days without hearing someone mention AI, automation, robots, or virtual reality. But one of the more unassuming technological developments is certainly nanotechnology. While it’s a little more of a silent trend, nanotechnology is set to switch up the way we develop and apply technology completely. Not only in the industry as a whole, but in all of our daily lives as well. There are a lot of areas where nanotech is already making a huge impact. But its ubiquity is only set to increase rapidly in the near future. Virtually anywhere we use a product, nanotechnology could play a role. Come with us as we explore exactly what nanotechnology is and how it works, how we’re using it today, and how we might use it tomorrow.

What Is Nanotechnology?

You probably already have a good idea of what technology is. In simple terms, nanotechnology is very similar, just on a much smaller scale. When we’re talking about nanotechnology, we’re usually talking about the study of these materials, as well as the design and development of nanostructures and devices.

The term “nano” refers to a nanometer scale of 1 to 100 nanometers. A nanometer is a tiny unit of measurement. A single meter is equivalent to 10 to the power of 9 nanometers, or a nanometer is equivalent to a billionth of a meter. Aside from the implications on economy and efficiency, this minuscule size affords many unique properties to the material that we don’t typically see. Nanotechnology represents a fascinating symbiotic relationship between many industries and sciences, including engineering, material science, biology, chemistry, and physics. The way these experts come together to develop technology previously unimaginable is almost as intriguing as the materials themselves.

What Are Quantum Effects in Nanotechnology?

Quantum mechanics is concerned with how matter behaves at the atomic level and below. A lot of the time, this behavior is counterintuitive, especially when considering traditional physics. Because nanotechnology works on such a minute scale, we observe some considerable quantum effects. Nanomaterials tend to have very high relative reactivity. Even some materials that are unreactive on a larger scale exhibit reactivity on the nanoscale. The considerably higher surface-area-to-volume ratio of nanomaterials gives rise to a greater density of electronic states. This means that reactions on the surface become much more frequent. It’s worth noting that the increased reactivity of nanomaterials is also in part due to non-quantum factors. This includes the number of reactive sites, functional groups, and surface energy, but quantum effects play a huge role.

Quantum confinement is also a significant factor in determining the properties of nanostructures and is at the core of quantum theory. At the atomic and subatomic levels, particles are quantized. This means that they exist in discrete energy levels, rather than in continuous energy bands. As the size changes, so does the gap between the highest occupied and lowest unoccupied energy levels. These are largely responsible for the electronic properties, which we can tune by varying the material’s size. 

Quantum effects don’t only affect the electronic nature of the material, but also its thermal and optical properties. For example, quantum dots are a type of nanoparticle that rely on the quantum confinement effect to perform their functions. As the size of the dots changes, the band gap energy also changes and so do their emitted wavelengths. This tunable optical behavior has many applications but is commonly utilized in the development of lighting devices, imaging, and even QD-OLED TVs.

What Are the Types of Nanomaterials?

All nanomaterials share the property of having a very high surface-area-to-volume ratio. But they can differ a lot in other aspects. At a high level, nanomaterials belong to four groups — carbon-based, metal-based, dendrimers, and nanocomposites. We’re going to briefly cover all of these next.

Carbon-Based Nanomaterials

As you can probably guess, these are made out of carbon and include carbon-based quantum dots and fullerenes. Whereas quantum dots are nanoparticles, fullerenes are carbon-based structures that generally have a diameter of around 1 nanometer. 

You can consider all fullerenes as alternative forms of carbon, known as an allotrope. Carbon has many forms, from coal and graphite to the more exquisite and uncommon diamond (yes, your diamond ring and your pencils are made of the same element). Fullerenes, however, are made of almost impossibly thin sheets of graphene carbon, only as thick as an atom. These sheets can form into tubes or spheres, such as the famous buckminsterfullerene, or buckyball. Fullerene spheres are incredibly stable to both pressure and temperature and we’ve even seen them in space.

There are various methods for producing fullerenes. But we usually make them either through vaporizing then condensing graphene, extracting them from a solvent, or the decomposition of carbon structures such as hydrocarbons. By adjusting the reaction conditions, such as temperature and the applied voltage, we can control the composition of the produced nanomaterials.

Metal-Based Nanomaterials 

When it comes to metal-based nanomaterials, the most common kinds are quantum dots, i.e. those made of cadmium or lead, and gold nanoparticles. Controlling the size of the quantum dot during production is crucial, so most methods center around optimizing this process. We can make dots by a controlled reaction in a solution or by reacting specific organometallic precursors. However, scientists can achieve finer control over their size and composition through depositing metal ions or atom-thin layers of material onto a substrate.

Gold nanoparticles, on the other hand, can be produced through the reduction of gold ions in specific solutions, growing them from tiny gold particles called seeds, or by depositing gold ions onto the surface of an electrode. As with carbon-based materials, we can meticulously adjust the reaction conditions are to produce the desired size and composition.

Dendrimers 

Dendrimers take their name from the Greek word for tree. This is because they consist of a core and an outer shell, along with several layers of branched structures. We can create dendrimers either divergently, i.e. from the core outwards, or convergently, i.e. from the outer shell inwards. As with other nanomaterials, we can design their properties with a great degree of precision, such as their solubility, size, and the size of their internal cavity.

Nanocomposites

Nanocomposites are interesting, in that they’re a combination of larger materials with nanomaterials. They’re generally one of three types, depending on whether they contain ceramics (nanoceramic matrix composites, or NCMCs), metals (metal matrix composites, or MMCs), or polymers (polymer matrix composites, or PMCs). The general process for producing any kind of nanocomposite is by choosing the desired base material, dispersing the nanoparticles through the matrix, and then processing the material. They can also be heat-treated following this, depending on the required properties.

Approaches to Producing Nanomaterials

While there are many methods involved in designing and producing nanomaterials, they can all be categorized as either following a bottom-up or top-down approach. The bottom-up approach involves building a larger structure from smaller component parts, such as nanoparticles or atoms. However, the top-down approach refers to miniaturizing a larger structure to the nanoscale, through methods such as lithography, etching, or cutting. The table below classifies some of the most commonly used methods according to their approach.

What Are the Applications of Nanotechnology?

The uses for nanomaterials are vast. For brevity’s sake, we give the main applications in the table.

The Future of Nanotechnology

The ongoing development of nanotechnology is certainly exciting. We’re sure to see even more advanced uses for these materials in the future. Drug delivery and medical treatments will become more refined, and medical diagnosis will likely be able to detect anomalies at the subatomic level. Computers will perform even better, and so will all the sensors we use in our tech.

There are a lot of potential concerns, however, especially when considering the introduction of nanomaterials into our bodies. Historically, humans have never been exposed to synthetic nanoparticles, so our biology hasn’t evolved and adapted to deal with them. While the goal of medical nanotechnology is to reduce the risk of adverse situations such as inflammation and toxicity, this does present a health concern. Of particular concern are free nanoparticles. These are not part of a larger structure and have more opportunity to migrate easily. We can inadvertently inhale these particles, or even absorb them through our skin due to their small size. The health implications of this are largely unknown. So it’s imperative that researchers follow strict safety guidelines and exercise caution when handling and developing this technology.

Wrapping Up

To summarize, nanotechnology is an extremely exciting industry, and nanomaterials are set to become a fixture in our everyday lives. From biosensors and medical treatments to making vehicles and solar cells, and even purifying water, these materials have an incredible number of applications. By controlling the production of nanomaterials at the atomic level, we can fine tune their electronic, optical and physical properties for any situation. While the potential benefits are huge, it’s crucial that scientists develop and manage nanotechnology responsibly, and regulate safety concerns.

Summary Table

The image featured at the top of this post is ©Panchenko Vladimir/Shutterstock.com.