Current wireless charging technology is predominantly inductive, using an electromagnetic field to transfer energy between two objects. This process is inefficient and causes devices to heat up more than they would if charged with traditional cables. Most types of inductive charging also require portable electronics to be placed on a charging pad because the potential distance between the wireless charger and device is minimal. In practice, this isn’t much better than using a cable to charge electronics.
Fujitsu and Wireless Charging
Researchers at Fujitsu labs have announced that they have successfully used a magnetic resonance system to wirelessly charge multiple gadgets simultaneously over a distance of about six inches. In theory, the technology should be able to charge objects at a distance of over three feet, but this has yet to be proven. What researchers can say for sure is that the system transfers 85% of energy, wasting only 15% in the wireless charging process over the six-inch distance. While this is impressive, the rate of efficiency could change drastically if the distance between charger and device is increased even slightly. Researchers are currently working to resolve any issues with longer charging distances before the technology is released. Fujitsu’s vision is for consumers to be able to place multiple gadgets on a table or other surface within a reasonable distance of a charging coil, allowing each device to charge at its own rate and fill its unique energy capacity.
How Fujitsu’s Magnetic Resonance Works
Fujitsu’s technology involves tuning two coils to the same frequency in order to enable a transfer of energy. A coil and capacitor form the resonator and transfer electricity between the transmitter (wireless charger) and receiver (device). Innovations include a magnetic field analysis simulator, a specialized circuit simulator, and automated system that precisely matches resonance requirements. The magnetic field analysis simulator analyzes the coil model and works with the circuit simulator, which analyzes resonance conditions, to enable quick and accurate wireless charging system design, reducing the total system design time to 1/150th of the current average.
Implications for the Future
The new magnetic resonance technology is on schedule to be incorporated into market products for charging mobile phones and other electronic devices in 2012. Researchers are also exploring the possibilities of using it to charge electric cars and enable wireless energy transfer between circuit boards or computer chips.