# Understanding Acoustic Levitation

in StemSocial2 months ago

I have always been fascinated by physics, the universe and innovative discoveries, I still remember that electromagnetic theory class at the university in which the professor explained the electromagnetic spectrum, understanding that was as if I had received great freedom through knowledge, in addition to understand how wonderful God has been in creation.

But when you think you've seen it all, things start to appear that continue to surprise and excite you, that's when I was able to see how some objects could be lifted from the ground using only sound or acoustic waves, I always knew that sound was important but I never imagined that such an achievement could be reached, since it is something exciting for me

I used to associate the word spectrum with ghosts, bad and scary things, so when the electromagnetic theory teacher said today we are going to see the electromagnetic "spectrum" I immediately thought: -Now I know clearly that the purpose of this course is to return crazy to the students- it was not for less, because all those explanations of the electromagnetic plane, laws of Lenz, Maxwell, formulas and calculations that made all the neurons heat up seemed destined to upset the students.

So it wasn't so surprising that now the professor started talking about the occult to end up terrifying us by invoking ghosts, when I saw the faces of my classmates I supposed that I wasn't the only one who made these conjectures so with more attention than ever I put my eyes on the professor waiting to see how it all ended.

Imagine that we have a wave generator capable of defining its amplitude and frequency, so we take an antenna and radiate that wave through space at a very low frequency, nobody can see it and nobody can hear it, but the wave exists and can be intercepted by an antenna , then through electronics that wave can be read and interpreted by these devices, we call this type of waves "radio waves" and we can use them to send information over long distances without the need for wiring.

But we take that same wave and increase its frequency at the same time that we decrease its length, we will reach the point of hearing it, that is, that wave produces a sound. So everything we hear is made up of waves that travel through the air with a certain frequency and length.

What happens if we keep decreasing its length and increasing its frequency? we will stop listening to it, we will go to the ultrasound level and then microwave.

We could keep increasing and that same wave that we once heard now becomes visible because at a certain frequency/length it becomes visible light, but it doesn't end there.

If we keep increasing then we will have X-rays and with each increase the property changes.

This bandwidth in which the wave changes from one nature to another is called the electromagnetic spectrum.

Source

That was really interesting for me, I had already heard things about radio waves such as that if you traveled faster than light and looked back you would see the past or that many of the stars that we see in the sky may no longer exist but we see them because its light reaches us many years late.

The truth is that a single wave can do many things just by changing its amplitude and frequency. When something surprises you, you don't easily forget it, so many years later, in my interest in technological advances, I was able to read an article in which they stated that they had designed a way to extinguish fires using sounds.

I thought, well if my house is on fire it would be good to have a guitar at hand, I can't imagine the surprise of everyone watching me play while the house burns, but even though I thought about it as a joke, I knew that it wasn't entirely impossible.
Then I saw that you could even lift things off the ground using acoustic levitation, it seems I was getting out of date with the scientific information so I decided to investigate.

Gravity plays a very important role in our existence, even so, from time to time we want to get rid of it. Who has not dreamed that they are flying? I do, and it's a nice experience, but what keeps us alive also limits us from not doing it, at least not naturally, I guess this is what has sparked the interest of many scientists over the years to independence from gravity when we need it.

Electromagnetic levitation is a reality today, they even have a train in China that works with this, and that's fine. It sounds logical that someone would look for a way to use the electromagnetic phenomenon for this purpose, after all an electromagnetic wave produces magnetism that in a certain way has similarities with gravity in terms of attraction.

But what has led to the study of acoustic levitation is something that I cannot understand, however I will explain what it consists of.

Ultrasonic waves are created, two sources placed one in front of the other, they emit similar waves that travel when they collide, they intertwine creating a standing wave capable of trapping an object in it, then with the speakers they can manipulate the object making it levitate using just those sound waves.

It is not at any frequency/amplitude, there is a specific place in the frequency spectrum where this is possible, according to my research it happens at a frequency a little higher than audible although it has been done with sounds as well.

Applications
Until now it has applications in the field of medicine in the creation of drugs, when you need to create something of great purity that even contact with a container can contaminate, then chemical reactions are carried out while the compounds are levitating, in this way you obtain the desired result.

Also in certain electronic applications, however this is still a very young technology, scientists are studying how to move larger objects and they are advancing in it, each time moving objects of greater mass.

We are sure to see a lot of exciting things in the future with this technology.