In 2007, we focused on the global climate, and as gas prices soared, more novel technologies emerged in the development of alternative fuel and power sources. Once again, electronics and computers became smaller, faster, and cheaper, thanks to advances in nano-engineering and alternative battery technologies. Homeland security continued to be a focus of research and development in new ways to protect ourselves and our soldiers. And a number of breakthroughs in the medical field brought the promise of revolutionary new diagnostic and treatment options.
Researchers in the Department of Physics, Department of Electrical Engineering and Computer Science, and Institute for Soldier Nanotechnologies (ISN) at Massachusetts Institute of Technology (MIT) have demonstrated wireless power transfer. This breakthrough could mean that your cell phones, laptop computer, iPod, and other portable electronics could charge themselves without being plugged in. Some may not even need their batteries to operate.
The team lit a 60W light bulb from a power source seven feet away with no physical connection between the power source and the bulb. The MIT team refers to its concept as “WiTricity” (as in wireless electricity). WiTricity is based on using coupled resonant objects. Two resonant objects of the same resonant frequency tend to exchange energy efficiently, while interacting weakly with extraneous off-resonant objects. A child on a swing is a good example of this. A swing is a type of mechanical resonance, so only when the child pumps her legs at the natural frequency of the swing is she able to impart substantial energy.
The team explored a system of two electromagnetic resonators coupled mostly through their magnetic fields; they were able to identify the strongly coupled regime in this system, even when the distance between them was several times larger than the sizes of the resonant objects. This way, efficient power transfer was enabled. Magnetic coupling is suitable for everyday applications because most common materials interact only very weakly with magnetic fields, so interactions with extraneous environmental objects are suppressed even further.
WiTricity is rooted in such well-known laws of physics that it makes one wonder why no one thought of it before. But over the past several years, portable electronic devices have become widespread, all of which require batteries that need to be recharged often.
For more information on WiTricity, click here.
Viruses are difficult to eliminate in drinking water using current methods because they are far smaller than bacteria, highly mobile, and resistant to chlorination, which is the dominant disinfection method used in the United States. By using elemental iron in the filtration process, the researchers were able to remove viral agents from drinking water at very high efficiencies. Of a quarter of a million particles going in, only a few were going out. The elemental or “zero-valent” iron (Fe) used in the technology is widely available as a byproduct of iron and steel production, and is inexpensive, currently costing less than 40 cents a pound. Viruses are either chemically inactivated by or irreversibly adsorbed to the iron, according to the scientists.
Besides helping to safeguard drinking water, the technology may have applications in agriculture. Integrated into the washwater system at a produce-packing house, it could help clean and safeguard fresh vegetables, particularly leafy greens like lettuce and spinach, as well as fruit. The Centre for Affordable Water and Sanitation Technology in Calgary, Canada, is exploring use of the technology in a portable water treatment unit.
For more information on the virus-removal technology, click here.