Nanosensors: The invisible machines of the future

There are many new sciences being developed in today’s world, one of these is the world of Nanotechnology where particles that are smaller than the width of your hair are being used to help doctors and scientists save lives. But obviously, you can’t see these particles with your naked eye. You will need the help of nanosensors, sensors that help scientists observe how nanoparticles work to improve their understanding of them. In this article we will explore how nanosensors work, the different types of nanosensors, and how they are used.

How things in the nanoscale operate

To understand what nanosensors do, you must understand how nanoparticles and how things in the nanoscale operate.

To be in the nanoscale you must be smaller than 10 nanometers, which is 10,000 times smaller than the width of a human hair. In the nanoscale, gravity doesn’t affect the particles as much as it does on the macroscale (which is our size) because things in the nanoscale don’t have much mass. So things in the nanoscale are governed by quantum mechanics.

One way nanoparticles are used in our everyday life is in soap. Hydrophobic particles and hydrophilic particles are in the soap. Hydrophobic particles dislike water and hydrophilic particles are attracted to it. When you apply the soap to your hands the hydrophobic particles surround bacteria not allowing it to escape and the hydrophilic particles kills it.

What are nanosensors?

There are two types of nanosensors, there are nanosensors that are larger than the nanoscale, and nanosensors that are below the nanoscale. Both types of nanosensors main purpose is to be able to observe the process of what’s happening in the nanoscale. But, the nanosensor which is actually in the nanoscale is much more efficient and widely used. In short, nanosensors are tiny sensors that help scientists analyze what happens in the nanoscale.

How do they work?

Most nanosensors work by measuring electrical charges in the nanomaterials which are then analyzed. For example, if a molecule of nitrogen dioxide hits a nanotube, the nanotube will lose conductivity, the nanosensor will notice this and send electric signals. In short, nanosensors work by detecting changes from external interactions with the sensor (with nanotubes) and then send an electrical charge.

Types of nanosensors

There are also many different classifications for nanosensors which focus on different things.

• Active nanosensors: Requires an external power source to operate
• Passive nanosensors: Relies on external factors to work.
• Absolute nanosensors: Have a set reference point.
• Relative biosensors: Have a chosen reference point by the operator.

There are also nanosensor classifications based on what kind of energy they can detect. The three main energy classifications are:

• Physical nanosensors: These nanosensors are used for measuring properties like temperature, pressure, flow, stress, strain, position, displacement, or force.
• Chemical nanosensors: Chemical sensors are used for finding the concentration or identity of a chemical substance.
• Biosensors: Biosensors are used for biologically active substances.

How nanosensors are significant.

There are many applications of nanosensors in the world today. There are many fields where nanosensors are used from medical technology to urban farming. Through the NASA Technology Transfer Program, NASA has developed a nanosensor that can run a medical diagnosis very quickly using your breath and it is not very expensive. In farming, nanosensors are used to detect soil humidity, pesticide residue and nutrient requirements. In addition to many other fields nanosensor technology has helped revolutionize many other industries.

Nanosensors role in the future

As of right now, nanosensors are still very new and have a lot of potential. Researchers are expecting nanosensors to be the new machine for running medical diagnostics and an easy way for people to access information on what’s happening at the nanoscale, but this won’t be until a few more decades. Until then researchers will still be developing the little sensors which could be the next big scientific breakthrough.

How nanosensors are made

The reason why we can’t use nanosensors everywhere is because someone has to build them. The process of building nanosensors or any other nanostructure is called nanofabrication. There are currently two different ways of nanofabrication. Top down fabrication is like building a block of wood with atoms and molecules. You repeatedly build that same layer over and over until you have met the desirable height. There is also bottom up fabrication which is similar to constructing a building with atoms and molecules. Most top down fabrication techniques involve etching. Etching uses acids, or it can use more mechanical techniques such as x-rays or electron beams.

Problems with nanofabrication

In our current state in the development of nanofabrication there are many problems with both methods of fabrication. The top down method is more efficient and faster than bottom up but is much more expensive. The bottom up fabrication is cheaper but it takes longer and is less efficient.

How to improve nanofabrication

To improve nanofabrication scientists are working on using the bottom up fabrication method and the laws of quantum mechanics to help the nanoparticles build complex structures all by themselves to make the bottom up method much more efficient. There are still many problems with this method that scientists are trying to overcome. There are some other ideas out there such as using better materials for nanostructures, and using the best from the bottom up fabrication method and the top down method to make a new method.

In conclusion, nanosensors, in the future could become one of the leading machines in medicine and hundreds of other fields. But, to make nanosensors more available we need to improve nanofabrication technology, most likely with the self assembling method to create a faster and more efficient nanofabrication.