Wireless technology. It is tidy for the organized, a leg-brace for the clumsy, and, much more importantly, the saviour of the avid video gamer. The once mind-numbingly Sisyphean task of untangling cords is behind us, due to the miraculous advent of remote technology. Internet access, game console controllers, Bluetooth and more are the new faces of the digital world. There is, however, a rather significant drawback; wireless devices are, well, wireless, so they must rely on their own power sources, i.e. batteries. Batteries, despite being more convenient than a bundle of mixed-up wires, are expensive, and extremely environmentally hazardous. From an environmental and financial standpoint, batteries are just as terrible as cords, if not worse. What we need is a new way of powering electronics, one that is safer for the Earth and our wallets, and is not incredibly annoying and inconvenient to use. Luckily, some nerds at MIT have discovered a revolutionary solution which may forever change how we use electricity, and reduce the shameful number of times that I trip over power cords.
At a TED conference in the July of 2009, Eric Giler demonstrated an absolutely remarkable new means of powering electronic devices: wireless electricity. Giler is the CEO of WiTricity, a company devoted to the research and development of wireless energy transfer. The concept of wireless electricity was originally conceived by Nikola Tesla, though it had not been fully realized until recently. In 2007, several theoretical physicists and engineers at MIT under professor Marin Soljačić developed and demonstrated a device which powered a typical 60W light bulb with an electric current that was two meters away. During his presentation at TED, Giler gave a similar demonstration. An electric current was run through a coil on the floor, which turned on an unplugged television sitting on a nearby stand, and caused a cell phone to begin recharging its battery.
Despite seeming like the handiwork of Satan himself, the basis of this wireless energy transfer is actually quite straightforward. The relationship between electricity and magnetism allows power to be transferred between two separate and unconnected points which are magnetically resonant (meaning that their magnetic moments are identical). To start, an initial current is run through a coil, which causes the coil to pulse at alternating current frequency, which generates a magnetic field. If a second coil has an identical magnetic resonance frequency, this magnetic field will induce an electric current within the second coil, which then transfers the energy to whatever device requires power (e.g. a cell phone which is running out of battery power).
Wireless electricity is the epitome of convenience, requiring no more human involvement then simply putting the device within the general proximity of the initial coil. It’s even safer than our current power sources. Wall outlets can be dangerous, especially to children, and batteries explode, leak, or short circuit if one isn’t careful with them. Conversely, the wireless transfer of electricity is completely safe. International standards regarding field exposure have limits set far above these devices, not to mention the fact that we live in a magnetic field anyway (it’s called Earth, ever heard of it?). In addition, the power is only transferred to devices with identical magnetic resonance frequencies, meaning that humans are not likely to be subject to random induced currents. So I won’t have to worry about charging my phone, using my wireless Xbox and controllers while charging my electric car, all without lifting a finger. This technology is the way of the future, leading us down a path of safer and more effective power usage, a path of more convenient digital media, and most importantly, a path not littered with tripping hazards. It’s energy at our fingertips, no strings attached.
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