[extropy-chat] nonradiative energies

scerir scerir at libero.it
Sat Oct 15 06:14:09 UTC 2005

What will be the next great invention on the order of the laser?  
We don't know, but clever new ideas keep coming along.  
The second-place award in the technological innovation competition 
went to Marin Soljacic (MIT) for his concept of wireless, non-radiative
energy transmission. Just as in the quantum case in which the
Schrodinger equation allows for a wave trapped in a box to tunnel
out, so Maxwell's equations allow for the leakage of electromagnetic
energy from an electromagnetic resonance object.  If another such
object were placed not far from the first one, and the resonant
frequencies of both were the same, then the energy could be
transferred between them with very little energy lost to other
objects in the nearby environmental that do not share the same
resonant frequency.  The transmitted energy, although
electromagnetic in nature, would not be referred to as "radiation"
since it is bound to the resonant objects.  It is rather an example
of "near-field" physics.  Soljacic avoids words like "antenna,"
since the process does not involve broadcasts of energy in the usual
sense.  In contrast, the vast majority of energy radiated by
antennas is typically wasted and lost into free space, while only a
small portion is picked up by the eventual receivers.  Instead,
Soljacic uses terms like "source" and "drain" in analogy with
transistors to describe the movement of energy.  An exemplary setup
might consist of a transmitter in a ceiling and devices in that room
(e.g robots, or computers) being powered wirelessly by this energy.

Marin Soljacic's page http://www.mit.edu/~soljacic/

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