WiTricity is an American engineering company that manufactures devices for wireless energy transfer using resonant energy transfer based on Synchronized Magnetic - flux Phase Coupling phenomenon (oscillating magnetic fields).
History
The term WiTricity was used for a project that took place at MIT, led by Marin Soljacic in 2007. The MIT researchers successfully demonstrated the ability to power a 60 watt light bulb wirelessly, using two 5-turn copper coils of 60 cm (24 in) diameter, that were 2 m (7 ft) away, at roughly 45 percent efficiency. The coils were designed to resonate together at 9.9 MHz (wavelength 30 m) and were oriented along the same axis. One was connected inductively to a power source, and the other one to a bulb. The setup powered the bulb on, even when the direct line of sight was blocked using a wooden panel. Researchers were able to power a 60 watt light bulb at roughly 90 percent efficiency at a distance of 3 feet. The research project was spun off into a private company, also called WiTricity.
The emerging technology was demonstrated in July 2009 by CEO Eric Giler at the TED Global Conference held in Oxford. In this demonstration, Giler shows a WiTricity power unit powering a television as well as three different cell phones, the initial problem that inspired Soljacic to get involved with the project. Automobile manufacturer Toyota made an investment in WiTricity in April 2011.
In September 2012, the company announced it would make a USD 1000 demonstration kit available to interested parties, to promote the development of commercial applications.
Technology
WiTricity is based on strong coupling between electromagnetic resonant objects to transfer energy wirelessly between them. This differs from other methods like simple induction, microwaves, or air ionization. The system consists of transmitters and receivers that contain magnetic loop antennas critically tuned to the same frequency. Because WiTricity devices operate in the electromagnetic near field, receiving devices must be no more than about a quarter wavelength from the transmitter. In the system demonstrated in the 2007 paper, this was only a few meters at the frequency chosen. In their first paper, the group also simulated GHz dielectric resonators. WiTricity devices are coupled almost entirely with magnetic fields (the electric fields are largely confined within capacitors inside the devices), which they argue makes them safer than resonant energy transfer using electric fields (most famously in Tesla coils, whose high electric fields can generate lightning), since most materials couple weakly to magnetic fields.
Unlike the far field wireless power transmission systems based on traveling electromagnetic waves, WiTricity employs near field resonant inductive coupling through magnetic fields similar to those found in transformers except that the primary coil and secondary winding are physically separated, and tuned to resonate to increase their magnetic coupling. These tuned magnetic fields generated by the primary coil can be arranged to interact vigorously with matched secondary windings in distant equipment but far more weakly with any surrounding objects or materials such as radio signals or biological tissue.
In particular, WiTricity is based on using strongly-coupled resonances to achieve high power-transmission efficiency. Aristeidis Karalis, referring to the team's experimental demonstration, says that the usual non-resonant magnetic induction would be almost 1 million times less efficient in this particular system.
History
The term WiTricity was used for a project that took place at MIT, led by Marin Soljacic in 2007. The MIT researchers successfully demonstrated the ability to power a 60 watt light bulb wirelessly, using two 5-turn copper coils of 60 cm (24 in) diameter, that were 2 m (7 ft) away, at roughly 45 percent efficiency. The coils were designed to resonate together at 9.9 MHz (wavelength 30 m) and were oriented along the same axis. One was connected inductively to a power source, and the other one to a bulb. The setup powered the bulb on, even when the direct line of sight was blocked using a wooden panel. Researchers were able to power a 60 watt light bulb at roughly 90 percent efficiency at a distance of 3 feet. The research project was spun off into a private company, also called WiTricity.
The emerging technology was demonstrated in July 2009 by CEO Eric Giler at the TED Global Conference held in Oxford. In this demonstration, Giler shows a WiTricity power unit powering a television as well as three different cell phones, the initial problem that inspired Soljacic to get involved with the project. Automobile manufacturer Toyota made an investment in WiTricity in April 2011.
In September 2012, the company announced it would make a USD 1000 demonstration kit available to interested parties, to promote the development of commercial applications.
Technology
WiTricity is based on strong coupling between electromagnetic resonant objects to transfer energy wirelessly between them. This differs from other methods like simple induction, microwaves, or air ionization. The system consists of transmitters and receivers that contain magnetic loop antennas critically tuned to the same frequency. Because WiTricity devices operate in the electromagnetic near field, receiving devices must be no more than about a quarter wavelength from the transmitter. In the system demonstrated in the 2007 paper, this was only a few meters at the frequency chosen. In their first paper, the group also simulated GHz dielectric resonators. WiTricity devices are coupled almost entirely with magnetic fields (the electric fields are largely confined within capacitors inside the devices), which they argue makes them safer than resonant energy transfer using electric fields (most famously in Tesla coils, whose high electric fields can generate lightning), since most materials couple weakly to magnetic fields.
Unlike the far field wireless power transmission systems based on traveling electromagnetic waves, WiTricity employs near field resonant inductive coupling through magnetic fields similar to those found in transformers except that the primary coil and secondary winding are physically separated, and tuned to resonate to increase their magnetic coupling. These tuned magnetic fields generated by the primary coil can be arranged to interact vigorously with matched secondary windings in distant equipment but far more weakly with any surrounding objects or materials such as radio signals or biological tissue.
In particular, WiTricity is based on using strongly-coupled resonances to achieve high power-transmission efficiency. Aristeidis Karalis, referring to the team's experimental demonstration, says that the usual non-resonant magnetic induction would be almost 1 million times less efficient in this particular system.
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