الكهرباء اللاسلكية WiTricity

هذه ورقة كتبتها في التقنيات الجديدة.
ملخصها هو أن الشباب في معهد أم أي ـي ما عجبهم أنهم يشحنون الجوال عن طريق تركيب الشاحن والأسلاك والوايرات اللي تضيق الخلق.
عشان جذي إخترعوا لنا كهربا وايرلس.
وسموها
"وايتريستي
الكهرباء اللاسليكية.
بصراحة شلت من بحثي قسم التداعيات الإقتصادية والإجتماعية لان يمكن أحتاج أني أغيرها
على العموم حتى وقت تغييرها ما بغيت أترجم البحث للعربي إلى أن أنتهي من الترجمة
والله يعينكم على كتابتي الإنجليزية.
...... والعربية بعد!!!! كمان
أخوكم غازي هادي الوادي
Introduction
Since I moved to my new place, I have freed myself and my two oldest daughters (Laila, 6years, and Dalal 4years ) from having our laptop machines attached to the phone lines and from competing for who uses the line to connect to the internet first. I got a wireless modem and enabled the wireless network cards on the laptops. That enabled all of us to connect and browse the net at the same time. However, as the youngest one is still not allowed to touch electric wires, for safety reasons, I have to get the laptops battery charged by myself everyday. The need for a solution that frees me from having to plug the computer everyday made me look up technologies that solve this need. My search results led me to WiTricity; a term used to describe the ability to provide electrical energy to remote objects without wires. This document describes WiTricity, its history and how it works. The document also discusses the future of this technology and the perceived economical and social impact of using this technology.
History
On June 2007, PhysOrg.com published an article on its website titled “Goodbye wires… MIT experimentally demonstrates wireless power transfer” it stated that “A team from MIT’s Department of Physics, Department of Electrical Engineering and Computer Science, and Institute for Soldier Nanotechnologies (ISN) has experimentally demonstrated an important step toward accomplishing this vision of the future. The team members are Andre Kurs, Aristeidis Karalis, Robert Moffatt, Prof. Peter Fisher, and Prof. John Joannopoulos (Francis Wright Davis Chair and director of ISN), led by Prof. Marin Soljacic. Realizing their recent theoretical prediction, they were able to light a 60W light bulb from a power source seven feet (more than two meters) away; there was no physical connection between the source and the appliance. The MIT team refers to its concept as “WiTricity” (as in wireless electricity)” (PhysOrg.com , 2007)
The Concept
Radiation methods
Various methods of transmitting power wirelessly have been known for centuries. Perhaps the best known example is electromagnetic radiation, such as radio waves. While such radiation is excellent for wireless transmission of information, it is not feasible to use it for power transmission. Since radiation spreads in all directions, a vast majority of power would end up being wasted into free space. One can envision using directed electromagnetic radiation, such as lasers, but this is not very practical and can even be dangerous. It requires an uninterrupted line of sight between the source and the device, as well as a sophisticated tracking mechanism when the device is mobile.
The key: Magnetically coupled resonance
To overcome the above problem, 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. In any system of coupled resonators there often exists a so-called "strongly coupled" regime of operation. If one ensures to operate in that regime in a given system, the energy transfer can be very efficient. While these considerations are universal, applying to all kinds of resonances (e.g., acoustic, mechanical, electromagnetic, etc.), the MIT team focused on one particular type: magnetically coupled resonators. 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. ” (Science A Go Go, 2007)
The design
“The investigated design consists of two copper coils, each a self-resonant system. One of the coils, attached to the power source, is the sending unit. Instead of irradiating the environment with electromagnetic waves, it fills the space around it with a non-radiative magnetic field oscillating at MHz frequencies. The non-radiative field mediates the power exchange with the other coil (the receiving unit), which is specially designed to resonate with the field. The resonant nature of the process ensures the strong interaction between the sending unit and the receiving unit, while the interaction with the rest of the environment is weak. ” (Hadley, 2007)
Radiation methods
Various methods of transmitting power have been known for centuries. Perhaps the best known example is electromagnetic radiation, such as radio waves. While such radiation is excellent for transmission of information, it is not feasible to use it for electricity transmission. Since radiation spreads in all directions, a vast majority of power would end up being wasted into free space. But “Moffatt, an MIT undergraduate in physics, explains: "The crucial advantage of using the non-radiative field lies in the fact that most of the power not picked up by the receiving coil remains bound to the vicinity of the sending unit, instead of being radiated into the environment and lost." With such a design, power transfer has a limited range, and the range would be shorter for smaller-size receivers.” (Hadley, 2007)
The Future
“As for what the future holds, Soljacic adds, "Once, when my son was about three years old, we visited his grandparents' house. They had a 20-year-old phone and my son picked up the handset, asking, 'Dad, why is this phone attached with a cord to the wall?' That is the mindset of a child growing up in a no-cables world. My best response was, 'It is strange and awkward, isn't it? Hopefully, we will be getting rid of some more wires, and also batteries, soon.'” (WiTricitynet, 2007)
WiTricity is still in its testing days; however, the results are promising. It has many bright sides and has a bit of time to reach a commercial level production. However, as many other technologies have done, it will eventually overcome its shortcomings and sets the stage for many other technologies.
Conclusion
WiTricity has many potential uses and advantages. It has several potential impacts on our lives both economically and socially, negatively and positively. However, human being will continue to adopt and maximize the benefit of new found technologies.

Reference List
Franklin Hadley, Goodbye wires…MIT team experimentally demonstrates wireless power transfer, potentially useful for powering laptops, cell phones without cords Institute for Soldier Nanotechnologies, MIT, http://web.mit.edu/newsoffice/2007/wireless-0607.html (retrieved on December 12th 2007)
PhysOrg.com, Goodbye wires… MIT experimentally demonstrates wireless power transfer, (Published: June 07, 2007) retrieved from http://www.physorg.com/news100445957.html (on December 12th 2007)
Science A Go Go, Wireless Power Transfer Revisited, 2007, http://www.scienceagogo.com/news/20070508001723data_trunc_sys.shtml (Accessed on December 12th 2007)
WiTricitynet, The Future Of Technology Today! 22007. Retrieved from http://www.witricitynet.com/ (on Dec 12th 2007)