Nanosensors — How Something Small Can Do Something Huge

Connor Wang
6 min readJun 12, 2020


Who’s a fan of Marvel?

If you are, you should know who Scott Lang is. He’s the superhero known as Ant-Man.

One of Ant-Man’s powers is to become extremely small, like an ant. You might think this power is useless amongst superheroes, because what can a super tiny hero do? In fact, small things can do a lot! Ant-Man’s ability has helped Dr. Hank Pym (a super smart guy who Ant-Man works with) discover more about the quantum realm, where everything is super small and measured on the nanoscale (more on that later). Ant-Man isn’t here on Earth to help us explore the quantum and nano realm, so we use nanosensors instead.

OK, what the heck are nanosensors?

Let’s start out with normal sensors. We have sensors everywhere: in our smartwatches, smartphones, houses, etc. They all measure and monitor things like heart rate, fitness level, carbon dioxide, all that stuff. Pretty simple. Now, nanosensors are like these sensors, but much smaller and slightly more complicated. Nanosensors detect different signals in different environments and quantitative values (or, you know, just information that can be written down with numbers). The type of signals nanosensors can detect include biomedical, optical, electrical, physical, and mechanical.

Nanosensors are really, really, small!

After all that, what’s the difference between normal sensors and nanosensors? Well, as the name suggests, nanosensors are measured in the nanoscale. The nanoscale is a scale made by scientists for describing or measuring any object that is between 1–100 nanometres (a billionth of a meter). The size of a nanosensor falls between 10–100 nm, meaning they fit into this category. To put this into perspective, the thickness of a sheet of paper is about 100,000 nm thick. Nanometres are pretty small! If we were to compare a nanosensor to a Fitbit, it would be like comparing a pin to a classroom.

Sounds cool, but why should I care?

You don’t have to be absolutely obsessed with nanosensors, but they’re still important. Nanotechnology is going to be a common field of work in the future, and they’re doing things we could never imagine a few years ago. It’s important to know all you can about these little things.

Nanosensors’ size, weight, and efficiency put them way ahead of normal sensors. The size of nanosensors allows for the manufacture of portable, hand-held, implantable, and even injectable devices. In addition, as a result of their minute size, these devices need less sample or reagent for analysis or operation, which saves money and time. Not only do nanosensors have an advantage over normal sensors, but they’re also important for our health and for science. Some uses of nanosensors are to detect the presence of chemical species and nanoparticles, and monitor physical parameters such as temperature. Nanosensors are so useful because these sensors are the only sensors that can measure on the nanoscale.

The ability to detect chemicals has useful applications in environmental science, where we might want to learn about the levels of particular nasty pollutants that might be present in the air or water.

One of the most useful applications of nanosensors is in medicine. Nanosensors in medicine could help us detect serious illness before it is too late, or help doctors track the progression of a disease. We could even combine nanosensors with other nanotechnology to treat a disease from inside the body, long before conventional medicine could even detect it.

A pair of tweezers hold a small nanosensor
A nanosensor developed by Nosang Myung. The purpose of this nanosensor is to detect harmful airborne toxins in foods. Picture copyright: University of California Riverside

It’s proven that nanotechnology will benefit us in the future; Scientists and engineers believe nanotechnology can be used to benefit human health now and in the future through applications such as better filters for improving water purification, more effective methods of delivering drugs in medicine, and new ways of repairing damaged tissues and organs.

All in all, nanosensors are pretty cool.

How do nanosensors work?

Now that we know what nanosensors are and what they do, let’s look at how they work.

To make it simple, nanosensors work like your nervous system. When you touch something hot, your nerves send electrical signals to your brain telling you that the object you touched is hot. Nanosensors function the same way. Nanosensors work by transforming the observed material or process into electrical signals, which turn into quantitative values, letting us analyze the results. Most nanosensors work by measuring electrical changes in the sensor materials. For example, if a molecule of nitrogen dioxide comes in contact with a chemical carbon tube nanosensor, it will strip an electron from the nanotube, which will make the nanotube less conductive. The nanosensor will notice this and send electrical signals. Nanosensors detect changes from external interactions and communicate with the other nanocomponents.

How are nanosensors made?

Nanosensors are made through a process called nanofabrication, which is the designing and manufacturing of all nanotechnology. There are two different methods of nanofabrication: top-down fabrication, and bottom-up fabrication. The first method, top-down fabrication, is a process that is similar to sculpting a block of stone, where the base material is sculpted to the desired shape. The most commonly used top-down fabrication technique is nanolithography. During this process, the material needed for the nanotech is protected by a mask, and the exposed material is etched away. Depending on the level of resolution required for the nanostructure, etching of the base material can be done chemically using acids or mechanically using ultraviolet light, x-rays, or electron beams. The second method, bottom-up fabrication, can be compared to building a Lego house, but instead of placing bricks one by one, it’s atoms or molecules that are painstakingly placed one at a time to build the nanostructure.

The problems with nanofabrication

If these nanosensors are so amazing, why aren’t we hearing about it on a daily basis? Well, some of the answer lies in manufacturing. After all, nanosensors are still in the early stages of development and they haven’t been perfected yet.

There are problems with both methods of nanofabrication, top-down and bottom-up. The main issue with the top-down method is the cost. The equipment required for this method is very expensive, even though the method is effective and efficient. The bottom-up approach is pretty much the opposite of the top-down method; it’s not too expensive, but it’s extremely time-consuming. Remember all the time you spent on that Lego Star Wars Death Star when you were younger? Imagine that, but with pieces so small you can’t see them with your naked eye.

Top-down vs. bottom-up methods of fabrication

In the end, the battle between top-down and bottom-up fabrication is the decision of money vs. time. We shouldn’t have to make this choice, and we should resolve this problem as soon as possible.

How could we improve nanofabrication?

This may sound a little far fetched, but what if we used AI for nanofabrication?

The most cost-effective method of fabrication is bottom-up, right? When analyzing the problems with this form of fabrication, we see that the design of it takes an abundance of time. That is because we are using human intelligence to develop technology when we could be using artificial intelligence to do it, time effectively AND cost-effectively, solving our problem.

Our world is advancing, and with it AI. Artificial intelligence has progressed a lot from where it was when it began. Just recently, AI invented a drug to help people with OCD that has been successfully tested on humans. Not only did it work, but the artificial intelligence was able to create this drug faster than scientists and doctors could. In the same way that AI helped us develop new drugs faster than we can, I believe it can model the process of bottom-up nanofabrication and find a more time-efficient way. If this idea worked, it would make nanofabrication a much, much easier process.

Closing remarks

Overall, nanosensors are incredible pieces of technology. There’s a whole world of nanotech waiting to be researched, discovered, and put to use. Nanosensors will revolutionize the world and provide lots of job opportunities in the future, so keep your eyes and ears open for these small pieces of tech.

I hope you enjoyed reading this and learning about nanosensors as much as I did.

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