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WiTricity the future of electricity

Written By: 

Vatsal Prakash

One spends their lifetime plugging things in. Be it either mobiles or laptop chargers or your television sets. But that’s all that’s about to change!

There is no argument in that we humans love electricity. We love that stuff so much that you can get an idea about it just by walking out on the street. There is about trillions of money spent in setting up power stations and wires carrying electricity from where it is generated to our homes and offices. Not only this. We love batteries too! An object that gives us power for a while before ending up in the garbage. But then there is a negative aspect to all this. Wires and batteries are awful. Just think about it, overhead wires gets damaged in rough weathers and can lead to calamities that can claim a human life. Plus imagine getting tangled in one of those wires under your computer desk. I know it’s pathetic.

As for the batteries, 40 billion of them are manufactured every year and when their work is done, they fall apart disintegrate and end up in a junkyard slowly decaying and releasing harmful stuff into the environment.

Imagine what if there was a technology through which we could built something that will never require us to plug our computers and phones into plug points ever again. That’s where wireless electricity (WiTricity) comes into picture.

The earliest vision of wireless electricity was thought by Nikola tesla. As great as an engineer and inventor he was, he dedicated his whole life to work with electricity. But his vision of a world running on wireless electricity was made possible for the first time by a MIT professor on his third sleepless night.

MIT Professor Marin Soljačić stood in his pyjamas looking at his phone. This was the 6th time in that month that he was woken up by the beeping of his phone warning him that the battery was low. In those moments a thought occurred to him. “There is electricity wired all through my house, my office and everywhere. The phone should take care of its own charging!” But to make this dream into a reality, one has to find a way to transfer power from these wired infrastructures to the phone wirelessly. Soljačić started working on a physical phenomenon that would make this possible.

Soljačić with a group of MIT physicists was able to power a light bulb of about 60 watt from a distance of two meters wirelessly. It was around 50% efficient which is still a thousand times more efficient than what a battery would be to perform the same task. The concept behind it was called the resonant energy transfer.

In this experiment, one of the coils was connected to an AC power supply having a resonant source. The other coil having a resonant capture device was connected to a 60W light bulb. They were suspended in mid-air by a nylon thread at a distance ranging from a few centimetres to 2.5 meters. The power supply was able to light the bulb wirelessly.


 

The experiment carried out by Soljačić and his students

So what is resonance

When two objects vibrate at a same frequency they are said to be in resonance. And the frequency at which they are vibrating is called resonating frequency. The energy can be transferred between two resonating objects at some distances.

Try to understand it like this, inside a transformer there are two coils of wires. They are very close to each other and transfer energy from one coil to another magnetically and wirelessly. But this phenomenon occurs over a very short distance. What dr. Soljačić did was separate the coils in the transformer to a greater distance than the size of those transformers and make it work somehow.

How WiTricity technology works

Imagine a coil with a capacitor attached to it. If we can make this coil to resonate, what happens is that it will pulse at a resonating current frequency which is fairly high. And if a “power capture coil” is brought close near to the source such that it will only work at the same frequency, what happens is the magnetic field will induce a current in the capture coil and a magnetic field around it. The magnetic fields of these two coils couple tightly and they transfer power efficiently.

In simple words what’s actually happening is you convert electricity into magnetic field and take that magnetic field and turn it back into electricity to use it but over some distance.

 

What are its benefits

This non-radioactive power transfer works on magnetic fields and is 100% safe in nature. It’s almost the same as the earth’s magnetic field. It reduces the cost when compared to wired connectors. Plus imagine how convenient it would actually be in day to day life for charging everyday electronics. It is also a very safe way of power transfer. Whatever the job may be difficult dirty or dangerous, wireless power delivers reliable and sustainable power.

What is the future of WiTricity

We can look forward for a world in which wireless power is integrated in all parts of everyday life. Wireless electricity is still a very new concept and in its development phase but it holds a wide range of applications where it can be used. The applications where it has been tested efficiently ranges from household appliances to industrial applications. We have been able to charge cell phones wirelessly and have been able to turn on our television sets wirelessly.

Wireless power holds potential for its uses in hospitals as it can provide a cleaner and more hygiene environment. It can be used in implanted medical devices which will reduce the infection. Imagine walking into your room and your desktop turning on automatically. Or imagine a wireless home where you place your lamp anywhere and it lights up or your phone charging while it’s still in your pocket. Imagine a world without wires. The idea is revolutionary!