WiTricity' system charges gadgets wirelessly from up to eight feet away - and could be in phones and tablets

WiTricity' system charges gadgets wirelessly from up to eight feet away - and could be in phones and tablets this year

Imagine a day when you can power your personal electronic devices without ever plugging them in?That will soon be a reality thanks to Witricity. The Watertown-based company creates wirelesss energy by using non-radiative magnetic fields to transfer energy. This infographic should help you understand how energy is transfered without using any wires.

 WiTricity Corp. technology will be the medium that ties our existing electric grid to a broad range of mobile and wireless devices—and enables the development of radically new and improved consumer, commercial, and industrial devices. WiTricity Corp. is now actively developing the core technology and additional intellectual property that will take this spectacular invention and turn it into commercially available products. Our mission is to develop a family of wireless power components that will enable designers and manufacturers in a broad range of industries to make their products truly “wireless”.


The technology, which will start appearing in gadgets from later this year, could also be used for tablets and small games consoles.
The American company behind it hopes that gadget companies will make special batteries with receiver coils to work with the system - or gadgets such as vacuum cleaners built to work wirelessly. 
And in the future the researchers believe they may be able to charge electronic cars and even heart pumps via a similar connection.

This only works within a short distance however because the primary coil is not that strong.
WiTricity expands this principle using a wireless connection so that it works up to several feet away, and perhaps even further.
The company has signed a deal with a semiconductor company in Taiwan to produce the coils, although the components will not be made available to the public.
If WiTricity is used by phone makers it will remove the pain of having to charge your mobile in public.
Douglas Stone, chairman of the Department of Applied Physics at Yale, said that technology had come along just at the right time.
He said: ‘The difference in what you can do when you charge at a very short range - essentially contact - and when you can do it at a meter or two, is huge’.

WiTricity’s technology can be used to power everything from your TV, cellphone, electric car and even medical devices.
Yinon Weiss, Director of Product Marketing for Witricity, told New England Post, they don’t plan on eliminating power lines, but they do plan on eliminating power cords.

 

     Currently they have 30 employees but plan on expanding next year.

Weiss says their business model is to enable companies to use Witricity technology. The company is in the process of licensing its technology for a wide field of use, building partnerships with major consumer electronics companies, car manufacturers, and medical device companies.

Understanding what WiTricity technology is—transferring electric energy or power over distance without wires—is quite simple. Understanding how it works is a bit more involved, but it doesn’t require an engineering degree. We’ll start with the basics of electricity and magnetism, and work our way up to the WiTricity technology.

Electricity: The flow of electrons (current) through a conductor (like a wire), or charges through the atmosphere (like lightning).  A convenient way for energy to get from one place to another!

An illustration representing the earth's magnetic field

Electromagnetism:  A term for the interdependence of time-varying electric and magnetic fields. For example, it turns out that an oscillating magnetic field produces an electric field and an oscillating electric field produces a magnetic field.
Magnetic Induction: A loop or coil of conductive material like copper, carrying an alternating current (AC), is a very efficient structure for generating or capturing a magnetic field.

If a conductive loop is connected to an AC power source, it will generate an oscillating magnetic field in the vicinity of the loop.  A second conducting loop, brought close enough to the first, may “capture” some portion of that oscillating magnetic field, which in turn, generates or induces an electric current in the second coil. The current generated in the second coil may be used to power devices. This type of electrical power transfer from one loop or coil to another is well known and referred to as magnetic induction. Some common examples of devices based on magnetic induction are electric transformers and electric generators.

Energy/Power Coupling:  Energy coupling occurs when an energy source has a means of transferring energy to another object. One simple example is a locomotive pulling a train car—the mechanical coupling between the two enables the locomotive to pull the train, and overcome the forces of friction and inertia that keep the train still—and, the train moves. Magnetic coupling occurs when the magnetic field of one object

An electric transformer is a device that uses magnetic induction to transfer energy from its primary winding to its secondary winding, without the windings being connected to each other. It is used to “transform” AC current at one voltage to AC current at a different voltage.

interacts with a second object and induces an electric current in or on that object. In this way, electric energy can be transferred from a power source to a powered device. In contrast to the example of mechanical coupling given for the train, magnetic coupling does not require any physical contact between the object generating the energy and the object receiving or capturing that energy.

Resonance

Resonance: Resonance is a property that exists in many different physical systems. It can be thought of as the natural frequency at which energy can most efficiently be added to an oscillating system. A playground swing is an example of an oscillating system involving potential energy and kinetic energy. The child swings back and forth at a rate that is determined by the length of the swing. 

The child can make the swing go higher if she properly coordinates her arm and leg action with the motion of the swing. The swing is oscillating at its resonant frequency and the simple movements of the child efficiently transfer energy to the system. Another example of resonance is the way in which a singer can shatter a wine glass by singing a single loud, clear note. In this example, the wine glass is the resonant oscillating system. Sound waves traveling through the air are captured by the glass, and the sound energy is converted to mechanical vibrations of the glass itself.  When the singer hits the note that matches the resonant frequency of the glass, the glass absorbs energy, begins vibrating, and can eventually even shatter. The resonant frequency of the glass depends on the size, shape, thickness of the glass, and how much wine is in it.

Resonant Magnetic Coupling: Magnetic coupling occurs when two objects exchange energy through their varying or oscillating magnetic fields. Resonant coupling occurs when the natural frequencies of the two objects are approximately the same.

Two idealized resonant magnetic coils, shown in yellow. The blue and red color bands illustrate their magnetic fields. The coupling of their respective magnetic fields is indicated by the connection of the colorbands.

WiTricity Technology: 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.

The WiTricity power source, left, is connected to AC power. The blue lines represent the magnetic near field induced by the power source. The yellow lines represent the flow of energy from the source to the WiTicity capture coil, which is shown powering a light bulb. Note that this diagram also shows how the magnetic field (blue lines) can wrap around a conductive obstacle between the power source and the capture device.