Nanosensors — What are They & Why They’re Important for the Future of the World
The human race is constantly evolving with time. We’re finding new ways to make our lives easier and better (the invention of electricity, the computer, and the smartphone), but at the same time making them worse (deforestation to create urban areas and polluting the hell out of our atmosphere with greenhouse gases). Nanosensors can help us push forward in time and help solve the problems we’ve created. How you may ask? Well, let’s first learn about Nanosensors, and then come back to the question of why they can help us in the future. Nanosensors and nanotechnology, in general, are intertwined already with many of the things we use in our day to day lives. They can be in the device you’re using to read this right now, underground in a water pipe that can help find a leak or in a medical device that can be used to help save lives. Nanosensors and other types of nanotechnology are everywhere, and are continuing to evolve as each day passes by.
To understand what a nanosensor is, you have to know what nanotechnology is. The term nano means small, in the case of a nanometer, nano refers to objects that are being measured in nanometers. One nanometer is a billionth of a meter. To put that into retrospective, a sheet of newspaper is about 100 000 nanometers thick. Nanometers are incredibly tiny, and nanotechnology allows for the adjustment of materials that are at nanometers, like atoms which are impossible to see with the human eye. The adjustment of these individual atoms acts differently than if they were to be adjusted on a larger scale. Through nanotechnology, conductivity, reflectivity and magnetism change when compared to a larger surface area. They can actually have enhanced properties like higher strength, lighter weight, increased control of light spectrum, and greater chemical reactivity.
Now that we’ve learned a little bit about nanotechnology and nanometers, let’s learn about how it works with nanosensors!
What are Nanosensors?
Sensor: a device which detects or measures a physical property and records, indicates, or otherwise responds to it.
A nanosensor is, you guessed it (nano + sensor): A sensor that has been shrunken down and can interact with other materials at nanometers. The sensors are able to detect the tiniest of changes that occur in the surrounding environment around it. They’re also much more sensitive and accurate than your standard sensor. There are two different types of nanosensors, one being mechanical, and the other being chemical. Chemical nanosensors work by measuring the change in the electrical conductivity of a surrounding nanomaterial. Many materials at the nanometer level have a high level of conductivity, which will be reduced upon the material absorbing a molecule or being moved around. Two examples of chemical nanosensors are nanowires and nanotubes.
Just like chemical nanosensors, mechanical nanosensors measure the electric charges of a nanomaterial. So what’s the difference between the two? Mechanical nanosensors use a completely different mechanism than the one used in its chemical counterpart. Mechanical nanosensors detect a change of electrical conductivity when the nanomaterial is physically manipulated/changed, compared to the chemical nanosensor, which measures conductivity after nanomaterials have bonded/absorbed another molecule. Now it makes sense huh? Chemical nanosensors = Chemical reaction, and Mechanical Nanosensors = Mechanical input. The removal of electrons/additions of electrons is what gives a chemical nanosensor a basis to operate on. Measuring the electrical changes in a surrounding area are measured via the mechanical nanosensor.
When building these tiny sensors, a process called nanofabrication is introduced. Nanofabrication has two methods, with the most common one being used is the top-down strategy. Where the current tech being used today is shrunken down to nanometers. In top-down nanofabrication, the integrated circuits chips get shrunken down by removing a single atom one after the one until the sensor has the right structure to operate at. The top-down fabrication is used when creating nanostructures that require long range for connections. You could think of the top-down method as taking the integrated circuits and sculpting them into something much smaller.
The other nanofabrication process is the bottom-up method. This complex is much more complicated as the sensor is structured atom by atom until the right structure is reached. They’re assembled via nanomachines that can identify each atom and where it’s supposed to go. Bottom-up nanofabrication processes typically don’t need expensive tooling to create nanoscale structures compared to the top-down strategy. However, it does rely heavily on the characteristics of the molecules. Use different particles, and it will either form different structures or not occur at all. Once we can initiate and control the bottom-up process, we can use it to build structures from the bottom-up (no pun intended 😊).
Why are they Important?
Nanosensors are potentially world-changing due to the fact that it can help solve many problems that we’re facing today, specifically chemical nanosensors and the environment, as well as diagnosing diseases in the medical field.
They’re almost better than regular sensors in every way, reducing the size of a sensor equates to faster response time, better signal to noise, increased data density, and having less impact on the phenomenon being measured, which leads to more accurate data. These sensors also have the portability to be placed almost anywhere.
The sensors can be applied to helping the environment by helping to monitor what’s going on in environmental samples. Chemical nanosensors can be used for the detection of trace amount of metals, nitrates, phosphates and pesticides in water samples. Nanosensors also have the ability to measure in real-time, which helps out a lot when monitoring an environmental sample. It can also be used to trace pollutants in the air, and report that information back to scientists who then can see what the air actually has in it.
Scientists can also help predict diseases faster than ever before. Nanosensors can now be entered into your bloodstream and detect anything that doesn’t look right and send that back out wirelessly to a computer for analyzation.
Before I end of my article, I want to discuss briefly about what the 2 main problems of the nanofabrication process is, and how we can fix them.
How can we Improve the Nanofabrication Process?
The two main problems that I see with the nanofabrication process is split up between the top-down strategy and the bottom-up method. The first problem is with the top-down strategy. It’s just too expensive. It’s more efficient than the bottom-up method and does take a faster time to finish, but the cost is what’s steering people away from using this certain method of Nanofabrication. With the bottom-up method, it’s actually kind of the opposite. It is cost effective compared to nanofabrication, but takes much longer to do compared to its top-down counterpart. Reliability is also an issue with the bottom-up method, as sometimes molecules have their own minds made up, and don’t want to interact with other molecules the same way we want them to do if that makes sense. (I hope so) I think continuing to work on Nanocomputers with AI that will help build the nanosensor from the bottom-up will be the best solution to the nanofabrication process. The more autonomous the process is, the more successful the process will be. (Less room for human error, making the process more autonomous makes it more efficient.)
As the nanofabrication process is continuously worked on and gets better, the sky’s the limit when it comes to nanosensors. This is a new emerging tech that I believe will impact millions, and perhaps billions of lives in the years to come. I look forward to what the future holds when it comes to the world of nanotechnology, and the innovations that will come with it.
