Nanosensors — Furthering Human Development on a Nanoscale
Nanosensors are, in a nutshell, what they are made out to be: sensors on a nanoscale. That seemed pretty simple, right?
Well, that’s not all there is to it.
Nanosensors technically are sensors on a smaller scale — but they are also so much more.
Sensors — In our everyday lives
I want you to take a look at the following emojis and guess which ones have or use sensors.
(bonus points if you can name the types of sensors)
🚕 ☝ 💻 🦑
(spoiler alert: the answer is all of them)
- That car (above — assuming it is a Tesla or any other type of level 2+ automated car — more info on that in another article — hint) uses a mix of LIDAR and radar sensors along with cameras (which you can view as sensors depending on your definition).
- But then comes the finger, on the surface, it may not seem to have sensors. The feeling of touch is caused by a skin layer called your dermis sensing your touch and communicating with your brain.
- Most computers nowadays usually have some form of biometrics (i.e. IR sensor or fingerprint scanner), definitely a check for sensors
- The squid itself is actually pretty straightforward squids can hear, sense their position in water, and see.
All examples of sensors
Debrief: The whole point of this exercise was actually to get your minds turning.
So what is a sensor? How does it function?
Generally speaking, a sensor is something that can detect (or sense) some specific value or specific property. In the earlier days, sensors used to be pretty chunky and impractical, not to mention expensive. But now sensors have evolved to a point where they are becoming increasingly smaller and efficient — enough that a radar sensor can be put inside a phone. In a nutshell, sensors can “sense” things like the presence of smoke from a fire or the light in your hallway.
So what is a nanosensor then?
To understand what a nanosensor you have to understand how things behave at a very small scale. The key concept to understand here is that as you go to smaller and smaller sizes, the traditional laws of physics don’t really apply — especially when you get to extremely small sizes (i.e. a couple of nanometers). This is why nanosensors are so amazing, they are so unique that things at the nanoscale are literally governed by quantum mechanics (which makes it all the more exciting).
TL; DR: Basically, a nanosensor is a sensor that can observe relatively small changes in an environment and react extensively.
But WHY are they so important?
Technology today, despite its speed compared to say the 20th century, is still very inefficient. A lot of the reason why people are increasingly looking at nanotechnology as the future is its capability to accomplish tasks very quickly and even do things that other sensors could never do.
Two examples prove why this is so crucial — look at the two biggest sectors in the world — healthcare and technology
Take, for example, a patient with type 2 diabetes. They require a lot of constant monitoring in order to make sure that they can get insulin when they need it. Typically this would require self-injection along with some rather bulky equipment to do this. But with nanosensors and other nanotechnology, this doesn’t have to be the case. The size of nanosensors allows them to be inserted into a patient and work remotely without the need for some kind of testing machine. But what’s also better is that they have a smaller power intake less power because of their small size.
And on top of that, other nanotech can be applied to help the patient receive the right amount of insulin without even having to use an injection.
Another great example is Moore’s Law. As stated microchips should get more transistors and become cheaper. but to a point, you can only fit so many transistors on a microchip, but that is only possible to a point
But that’s such a small user case — not everyone has medical problems so what else can it be applied to?
What’s nice about nanosensors is that they can be applied almost anywhere and drastically help out in that field. For example, the smartphone market — people are becoming increasingly expectational of more efficient phones that don’t have too many trade-offs.
Enter: nanosensors (again)
Features like a radar sensor, which are only in a handful of phones at the moment, can be brought without having to compromise the aesthetics of the phone. But also they can be useful to the performance of the phone like detecting critical temperatures or even utilizing cameras for different functions — all achieved with nanotech and nanosensors.
But they also have a plethora of other advantages including:
- Better durability — their small size makes it less likely to say chip like a bigger sensor would
- Insanely low latency — again the small size makes it so that data and electrical signals have to travel less distance
- Literal multitasking capabilities — it can do what most humans can’t: multiple things at one time
- Less of a need for bigger samples for analyzation — especially in cases like forensics this could prove vital as it would mean the difference between life and death
Are nanosensors all the same? You make it sound like it’s a one-size-fits-all case.
Contrary to popular opinion nanosensors are not all the same. In fact, they have multiple types each with their own pros and cons, here a few:
- Active nanosensors — these can send their own signals (which is really useful in the diabetic patient situation that I previously mentioned)
- Passive nanosensors — these lack the transmitters that active nanosensors have and rely on like a sort of inference/critical thinking step by looking at multiple environmental factors to look for a change. (This is kind of like how you look for a chemical change between two or more substances)
- Absolute nanosensors — these are really exciting because they can observe any change by using one quantitative or qualitative piece of data as a reference
So, you might look at this and say, “wow this sounds cool and could definitely be helpful, but how does any of this work?”
Like I mentioned before, nanosensors don’t really operate on the same principles that bigger things would. So in this same way, nanosensors really operate on a different sort of concept.
Most normal sensors by detecting a physical action and then translating that data into a corresponding electrical signal. Something to notice here how it has to have an external power source and needs a physical action to occur in order to function. Also, it needs a very large sample size to work with — not very efficient.
A nanosensor, on the other hand, works by looking at the electrical charge of the material doing the actual sensing. This concept is sort of like the absolute nanosensor that I mentioned earlier — there is usually a reference point to tell.
Take a deep breath we’re only halfway there.
Nanofabrication — Cooler than it sounds
Nanofabrication is the fancy term used to describe how nanosensors are built. Basically, it can be split into two main types of methods: top-down fabrication and bottom-up fabrication. All have their pros and cons:
Top-down fabrication — this is similar to taking raw materials and shaving it to specifications.
- You can really make it to any specification you desire — there is no limit to how much you can shave or not shave.
- It leaves a lot of creative freedom to the designer/creator.
- The products are unique because this is the equivalent of hand-crafting so it can root out bad designs in the nanofabrication process.
Cons: (unfortunately quite a bit)
- This process is usually extremely time-consuming and requires patience — which most may not have
- It also uses harsh chemicals to do some of the grunt work — environmental enthusiasts may not appreciate that as this technology becomes more widely embraced
- There is a lot of waste produced — humans are looking for more sustainable ways of life and while there may be repurposing methods out there it might not be widely implemented yet
- Things are not replicable — because everything is unique it is hard to scale up production to meet demand in the future
Bottom-up nanofabrication — This is a bit more of a sustainable method where the equivalent is more so of building rather than chiseling like the top-down nanofabrication method. This method also relies on a simple environment for the assembly to take place on its own.
- This wastes fewer materials — so resourcing materials would be a lot easier than the top-down fabrication method
- Expensive equipment typically isn’t needed — the tools to finely chop down that metaphorical piece of marble in the top-down fabrication method aren’t needed so it could potentially be more cost-effective
- Less labor — a lot of what this method is about is using the abilities of particles to build themselves
- This method revolves around a controlled and simple environment — this may not always be the case since environments are usually hard to control
- This method is still very new and has mostly been experimental — we don’t know how effective this thing could be.
If we go a bit deeper into how the process of bottom-up nanofabrication works we can see how it sort of is a bit more specific as we can characterize bottom-up nanofabrication as self-assembly. We can sum up the advantages and disadvantages below:
Pros of self-assembly
- It is really useful when you understand the characteristics of certain particles and how they form structures — so this can be useful if trying to mass-produce a certain pattern or design
- It is really useful on a small scale because of how easy it is once you have done the research and experimentation involved with whatever particles you want to use
- The manufacturing process will become easier — machines can literally build themselves because of the way these particles form
Cons of self-assembly
- If you want to apply this method with a variety of particles with different properties, the process is redundant — a lot of the problem is that we don’t fully understand how self-assembly works
- When things build themselves it is a bit unpredictable and you have to be very precise — in order to apply this method it takes a lot of precise work and experimentation as most of the work would involve testing certain independent variables for their significance and overall effect in the self-assembly process
For a bit of a more visual description here is a little video:
Is there any “perfect method” of nanofabrication?
Sadly not that we know of. However, there are always ways to improve the process:
- Invest more in the research of nanofabrication and how we can efficiently research the properties of particles rather than through just blind experimentation.
- There is a new technique that has recently emerged that improves off of the concept of bottom-up nanofabrication called DNA-based self-assembly which offers a more flexible process in terms of nanofabrication
- Of course, there is always the possibility of making taking the best of both the top-down and bottom-up process and making a completely new process
So what’s the purpose of this whole article? Why should I care?
Well, believe it or not, the world is constantly evolving and there are new technologies constantly emerging and helping humanity develop as a species. Especially at the forefront is nanotechnology as its help is super widespread, from clothing all the way to medicine nanotech can help us become efficient beyond our wildest dreams. But even more specifically, nanosensors can especially help advance humanity to other planets and even solve some of the most widespread problems like cancer.