Remember those cartoons with mad scientists who were hell bent on destroying the planet. Ever wondered of such an eccentric, insane, totally flipped out mad-scientist actually existed? Well, my friend, you will be happy to know that such a person did exist. No, it wasn’t Albert Einstein (one pic with your tongue out does not a mad scientist make). It was actually the most badass scientist in the history of ever – Nikolas Tesla.
Sometime in 2007, scientist at MIT (the super-genius adda) transmitted electricity through air, without any wires at a distance 7 feet. Tesla lit 200 bulbs at a distance of 26 miles – in 1899 – without wires.
Wireless power is a damn nice concept. Imagine charging your cell phone or iPod without those stupid adapters and wires. I used to think that would be possible only in paradise. But I tend to be wrong.
There are quite a few methods that can be used to transmit power wirelessly – Induction, Resonance and Long distance methods – read on to know more about them (you could just skip ahead to see a TED video of wireless power demo)
The induction method for wireless transfer of power is actually very simple stuff and already being used commercially. You must have learnt in school that whenever an electric current passes throuh a wire, it creates a magnetic field around the wire. If you bend the wire into a coil, obviously the magnetic field gets amplified. Increase the number of coils and you increase the magnitude of the field.
If you bring another coil goes enough (within the range of magnetic field), then electricity gets induced, i.e, transferred to the 2nd coil. Transformers (not the robotic kind, the real ones) work on the same principle.
Commercial application: Edison electric's powerdesk (put link) uses this method to charge various electronic devices like cell phones and laptops wirelessly.
Ah.. resonance. The concept we all knew and loved. Well, kind of :P
The buggers at MIT used the concept of resonance to transmit electricity through air. They theorized that the induction can take place a little differently if the magnetic fields around the pair of coils resonate at same frequency. So they used a curve coil wire as an inductor and attached a curved capacitance plate (that can hold a charge) at both ends. As electricity flows through the coil, it begins to resonate. They resonant frequency being the product of the capacitance of the plate and inductance of the coil. Watch this awesome video for more :
Long Distance Wireless Power
The above methods can only manage to send power over short distances. Scientists are working on methods to transmit power from long distances - like space to Earth. Yes, awesome idea!
Sometime in the 1980s Canada's Communications Research Centre created a plane that could run off beamed power from the Earth. It was called Stationary High Altitude Relay Platform (SHARP, yes very clever). This plane could fly continuously for months!!
The secret to SHARP's unlimited supply of power is - the scientists had created a ground based microwave transmitter. This transmitter, sent out microwaves, which were picked up an antenna at the top of the plane. This antenna also acted as a rectifier which would convert the energy from microwaves into power (DC electricity).
Scientists are planning to create a cluster of solar plants on the moon, transmit power from there to a cluster of a satellites which would then relay it towards earth. But this idea has it's range of problems - Some people would not be comfortable with the idea of having microwaves all around them. Not to mention the setup and maintenance costs would be exorbitant. But, I am positive these things will be dealt with time..
Wireless power isn't far away. We already have charging mats, so methinks the day when we would be completely free from wires is not that far away!
Oh, and if you misspell scientists, you might end up with scien-tits. :P