Friday, March 14, 2014

From Wired to Wireless Electricity

It just boggles my mind when I find myself surrounded by the spaghetti of wires in this age of technology. Why do we need to plug all of our gadgets and appliances to the power sockets attached on the walls? To do so, we need to keep the appliances closer to the power sockets which limit our options to arrange our rooms according to our wishes. And that must hurt the ‘interior decorator’ in us.  I always thought that why can’t we simply take the clues from the telecommunication industry that has succeeded to become wireless to a significant extent.  

So one day I came across a segment on Richard Quest’s show on CNN ‘QUEST MEANS BUSINES’. The segment featured a company named ‘WiTricity’ that is involved in the innovation of wireless electricity. I straightaway browsed their website ( and gathered the following details:

The beginnings:

WiTricity Corp. was founded in 2007 to commercialize the exciting new technology for wireless electricity invented at the Massachusetts Institute of Technology (MIT).

MIT Professor Marin Soljačić conceived the idea while staring at his cell phone on the kitchen counter. It was probably the sixth time that month that he was awakened by his mobile phone in need to be charged. At that moment, it occurred to him, “There is electricity wired all through this house, all through my office—everywhere. This phone should take care of its own charging!” But to make this possible, one would have to find a way to transfer power from the existing wired infrastructure to the cell phone, without wires. Soljačić started thinking of physical phenomena that could make this dream a reality.

To achieve wireless electricity transfer in a practical and safe way, it is necessary to use a physical phenomenon that enables the device and the power source to exchange energy with no or minimal interaction with living beings and other environmental objects. The phenomenon of strongly coupled resonators did the trick and the physical theories were developed.

Afterwards, the experimental design consisted of two copper coils was developed. One of the coils, connected to an AC power supply, was the resonant source. The other coil, the resonant capture device, was connected to a 60 watt light bulb. The power source and capture device were suspended in mid-air with nylon thread, at distances that ranged from a few centimeters to over 2.5 meters.  Not only was the light bulb illuminated, but the theoretical predictions of high efficiency over distance were proven experimentally. By placing various objects between the source and capture device, the team demonstrated how the magnetic near field can transfer power through certain materials and around metallic obstacles.

How it works:

WiTricity power sources and capture devices are specially designed magnetic resonators that efficiently transfer power over large distances via the magnetic near-field. These proprietary source and device designs and the electronic systems that control them support efficient energy transfer over distances that are many times the size of the sources/devices themselves.

Practical application:

WiTricity technology can be used to provide:

Direct Wireless Power—when all the power a device needs is provided wirelessly, and no batteries are required. This mode is for a device that is always used within range of its WiTricity power source.

Automatic Wireless Charging—when a device with rechargeable batteries charges itself while still in use or at rest, without requiring a power cord or battery replacement. This mode is for a mobile device that may be used both in and out of range of its WiTricity power source.

So now we can say that the wireless electricity is here and soon we will be able to live in a wire-free world. I hope our future generations will not even have any idea about these wires.

Note: The technical parts of the content has been taken from WiTricity website (