“Superlens” may solve wireless charging dilemma
techpageone.dell.com
techpageone.dell.com
1) Batteries get enough capacity so you only need to charge them once a month.
2) Batteries can be fully charged in a short period of time, say one minute, we wouldn't bothered very much to have to plug them in once a day.
3) Carrying around a device at home or work for few hours a day will keep the device charged for a whole day (via the "superlens").
Any of the aforementioned solutions and perhaps few others would solve the issues we have with batteries in our handheld devices today. For cars, trains and other battery uses, that's another thing.
Hint: There's a reason this requires METAMATERIALS to work over any reasonable distance.
But inductive coupling? No - it won't even interact, which is what this article is about.
Inductive coupling means a couple of inductances interact with each other. This is the reason it is called "coupling". And yes, this interaction means photons, depending of the frequency of the resonator of higher or lower frequency.
They use a medium, a channel, the most efficient one is ferrite, but it could be the air, that usually it is very inefficient because the electromagnetic radiation escapes and is absorbed by other elements or just dissipated.
You could improve efficiency making it use resonance, that is you trick your design so in normal circumstances you reuse the electromagnetic energy that is reflected by the geometry of the space.
The problem (of all open systems instead of closed circuits)is what happens when your body acts as a lower impedance for this radiation than the medium. It could in fact absorb a big amount of energy on a very small amount of time.
Geometry of the body is very complex, small parts of your body could resonate with some frequencies, and when there is noise like in transitories you add lots of frequencies.
Like you do?
Do you understand non ionizing radiation?
Some people are so ignorant, that they don't even know what they don't know.
I can kill a rat with non ionizing radiation. I could introduce it on a microwave or put it under a laser, or in the oven(IR).
With enough energy density, I could create devastating effects on any living organism. Nature protects against natural sources of radiation, like the light of the sun, but does not protects about artificial ones, it is very simple to blind someone with a IR laser she does not see.
You can use non ionizing radiation to make resonate the electric nervous systems like the US army is testing, with enough energy it kills you(we need electric operated muscles like the heart and lungs to operate to live), and lots of other funny things.
Let's not get carried away here. We've been talking about wireless transmission of electrical power for a while now: http://blogs.intel.com/intellabs/2008/10/02/rattner_the_prom....
What was considered dangerous in the past is dangerous today.
It is what was not considered dangerous in the past what we know today it is dangerous, like x-rays(they used it with pregnant women and basically killed a lot of people for ten years), powerful RADAR, tobacco(yes you can see advertisements on youtube of how innocuous it was), benzene, asbestos, pfcs, nuclear radiation(Curie couple died from that).
It was only after being proven that a technology kills thousands of people, that this tech is controlled.
For me it is a great idea to find guinea pigs for testing new technologies, but don't test it with me against my will sending radiated energy in the air.
If it is, then consumption is too high. Few hours of use is not "fine". Sure, if I use it as just a phone it can last week.. but once I use it as a computer, it drains pretty quickly.
I'm not sure that I actually get with everything blaring (the quickest I uncharge my phone is when I have both radios going as I have a tablet using it as a tether) though it sometimes isn't so I carry an "emergency" battery charger with me when travelling.
I agree that battery life doesn't need to improve that much if we could recharge it in a dramatically more convenient way, but 30 seconds charge every few hours sounds insane to me.
Anyway, smartphones last way more than 2 hours unless the battery has been abused for years.
And you could always bring juice with you if you have to use intensively for long periods your phone outside of civilization for some reason. Just pack eight 2700Mah Eneloops and you are fine. You need very simple transformer and usb connector.
Current phones are fine for that (especially with reasonable usage of "navigation" and extra battery as you said). 2hr-lasting phone wouldn't.
My X1 Carbon laptop may not have the world's best battery life, but being able to recharge it to 80% in ~30 minutes is fantastic. It's saved me on many occasions when I've been heading out of the house and realized that I forgot to charge it or needed to charge in a coffee shop where I couldn't sit near the outlet.
I can only assume the lack of this charging speed in most products means that it's either quite detrimental to the battery longevity or the cost/weight of the electronics outweighs the benefit, or both.
You don't really charge your phone, you just put it on an allocated area of your desk.
a) you need to remember to do (my phone currently lives in my pocket at work when not in active use) and to undo - i.e. pick it up again when you wander off
b) needs you to be near your desk at some point. I can often be away from any power source for many hours at a time - more than long enough to drain an average smartphone's battery with reasonable use.
Having said that, I actually understand the appeal of charging mats and the like, because they replace a small but persistent friction (find a charger, plug in the charger, plug in the phone, unplug the phone, plug the phone back in...) with a near-frictionless experience, if you don't count the cost. I'd like to see better conductive charging designs, but it looks like inductive has won out.
Or do they have some forward model to predict the outcome before they build it, but given the often inexplicable results that doesn't seem possible.
Where do the ideas come from?
I probably have some of the details of the technique wrong, I am trying to remember a talk from a year ago. If you want more detail, look at John Pendry's papers (he is probably the leading theorist in metamaterials). http://www3.imperial.ac.uk/people/j.pendry
The MIT spin-off WiTricity has been working on a better(?) solution since 2007, they have been consistently overpromising and underdelivering, but recently they showed this nice-looking device: http://gigaom.com/2014/01/09/video-wirelessly-charging-your-...
Personally I believe it would need a few meters' range before it becomes really useful - the point where you rarely need to consciously charge your phone because it is always charging when you're at home.
(1) If the receiver loop isn't "inside" the transmitter loop along the normal of the loop area then efficiency falls a bit (2) Efficiency depends a lot on the orientation of the device being charged. If the receiver loop isn't very nearly coplanar with the transmitter loop, efficiency bombs (3) Range is fairly limited (4) When you have multiple devices charging concurrently, efficiency falls for every individual device being charged as magnetic resonance cannot be achieved nearly as well for more complicated multi-body flux loops
Witricity has been trying to push electric car charging as for that application these downsides don't matter as much. But even there, you get something like 50% efficiency. Do you want to nearly double your electricity costs just to avoid plugging in a cable? Interesting technology, but it doesn't see like a worthwhile proposition to me.
General purpose wireless power transmission is a really difficult problem. I was interested in the ultrasonic acoustic approach that uBeam is pursuing but that has its own slew of problems.
noun noun: dilemma; plural noun: dilemmas 1. a situation in which a difficult choice has to be made between two or more alternatives, esp. equally undesirable ones.
#firstworldproblems
While some sources call into question the health effects of EM radiation, radios aren't causing vomiting and hair loss unless they're also made of radium.
The main danger is power level causing heating/burns - and a microwave operating at 1000W+ is going to do that far more easily than a router with 1W at most.