The largest remaining impediment to truly wireless information technology is the need to recharge. We already know how to send information wirelessly, and we’re getting better at it all the time. But sending power through the air remains problematic.
There have been major advances in recent years. Collimated beams of microwave or infrared laser light can do a pretty decent job in the right conditions, and the field of wireless power transmission is by now well understood.
Unfortunately, bad things can happen when people get in the way of a power beam. But it occurs to me that soon this may not be a problem.
We tend to think of people as fairly fast moving. The typical human can run across a room very quickly, and turn their gaze to stare into an unfortunately placed laser beam in literally the blink of an eye. So placing people and high powered energy beams in the same room would seem to be a bad idea.
But “fast” is relative. A blink of an eye is rarely faster than 1/10th of a second, and typically takes three or four times longer. No matter how fast the fastest human can move, thanks to Moore’s Law we can now easily track where people are in a room, and actively re-aim energy beams so that no human could ever “cross the streams” (to quote Dr. Egon Spengler).
I have no idea whether people are working seriously in this direction. But it’s clear, if you think about it a bit, that no “science fiction” level of technology is required.
We already have the technological capability to provide perfectly safe ubiquitous wireless power transmission. All that is needed is a little engineering.
Hmm, sort of a Mosquito Laser, but running in reverse – avoiding obstacles instead of deliberately zapping them.
http://en.wikipedia.org/wiki/Mosquito_laser
Yes and no.
On one hand, just being able to steer and rapidly switch beams is very doable, but there are couple of flies in that ointment; firstly, reflection and diffusion even when you don’t stand in the way of the beam (you end up in a microwave oven), and secondly the safety controls needed (I don’t think people will put up with wearing shielding as a tradeoff).
On a much more feasible front is a combination of evanescent waves (known as Near Field and used in NFC), which can be captured with metamaterials and cannot be absorbed by people without touching the emitter, and much lower power requirements. There are already devices that can recover power from wifi and other environmental RF sources, so an increase in this efficiency and a reduction in power requirements should push a much larger class of devices into the Never Needs Batteries group. Phones and other power-hungry devices should be able to make use of evanescent power, particularly if it is supplied by collectors in your clothes or other power sources on your person.
Phil: Yes, I’m familiar with Near Field and there is definitely an argument for going in that direction. One issue is that their relatively long wavelengths mean that you can’t really do any spatial phase control.
If you go to smaller wavelengths — perhaps as small as the far infrared regime — then you can create a kind of active dynamic hologram, where you focus coherent energy to only the places you want it, and not to the places where you don’t want it.
If you know the characteristics of the room, then you can create a coherent signal for that space, taking into account reflections off room surfaces and furniture in your dynamic construction of the phase-coherent signal.