Using a laser to wirelessly charge a smartphone safely across a room(phys.org)
phys.org
Using a laser to wirelessly charge a smartphone safely across a room
https://phys.org/news/2018-02-laser-wirelessly-smartphone-safely-room.html
58 comments
I was thinking "what if you increase the frequency to where the eye doesn't care" then I thought about how radio waves pass through our bodies and I remembered: wait a second, there is just one radiomagnetic spectrum!!!
As a page I googled states: "Optical radiation called light is the same thing as x-ray radiation is the same thing as microwave radiation is the same as infrared radiation is the same as radio waves."
0f course, when I think of radio waves they radiate out all over the place - but so does most light that isn't a laser.
Is there a "laser" in the higher, safe radio frequencies (which just pass through the body)? By laser I mean it's super focused with very tight parallel rays.
Could this be put in place of this system? After all the hard part of this system is aiming the laser, which this article says is done through active "sonar" (an acoustic beacon which is then localized).
Why not then target it with a radio "laser"?
As a page I googled states: "Optical radiation called light is the same thing as x-ray radiation is the same thing as microwave radiation is the same as infrared radiation is the same as radio waves."
0f course, when I think of radio waves they radiate out all over the place - but so does most light that isn't a laser.
Is there a "laser" in the higher, safe radio frequencies (which just pass through the body)? By laser I mean it's super focused with very tight parallel rays.
Could this be put in place of this system? After all the hard part of this system is aiming the laser, which this article says is done through active "sonar" (an acoustic beacon which is then localized).
Why not then target it with a radio "laser"?
There are longer wavelength amplification by stimulated emission of radiation (LASER without the L for light) devices but there are technological limitations like cavity size (often larger) and lower power. An example used in astronomy is the MASER: https://en.wikipedia.org/wiki/Maser
If they use one that can pass through you harmlessly most of it will probably also pass through the device wasting energy.
how do you figure? we aren't made of metal.
My dad’s vision blue-shifted over a career of laser research. He can see a bit into the ultraviolet spectrum but he almost cannot distinguish red at all. This is apparently not too rare among people with a lot of laser exposure, which inevitably crosses eyes.
And I'm pretty sure someone could accidentally a wave a fork into the path of the main beam without it intersecting a guard beam, based on that photo. -.-
The article makes brief mention of this...
the emitter detects this within a fraction of a second and deploys a shutter to block the charging beam before the person can come in contact with it
A mechanical shutter also seems strange --- cutting power to the laser would probably be faster by at least an order of magnitude if not more, if it's a solid-state type.
As the memorable sign says, "Warning: Do not look into beam with remaining eye."
the emitter detects this within a fraction of a second and deploys a shutter to block the charging beam before the person can come in contact with it
A mechanical shutter also seems strange --- cutting power to the laser would probably be faster by at least an order of magnitude if not more, if it's a solid-state type.
As the memorable sign says, "Warning: Do not look into beam with remaining eye."
This project screams lack of imagination and downright incompetence.
You need case-by-case legal paperwork to do high power (i.e. more than a few tens of mW) laser shows in the US if there's any chance of the beams scanning the audience.
The idea that you can set up a 2W laser in your living room and make it 100% safe by adding mechanical movement detection is outstandingly stupid and ill-advised.
You need case-by-case legal paperwork to do high power (i.e. more than a few tens of mW) laser shows in the US if there's any chance of the beams scanning the audience.
The idea that you can set up a 2W laser in your living room and make it 100% safe by adding mechanical movement detection is outstandingly stupid and ill-advised.
Not to mention the potential weaponization of these things. Forget IoT botnets, hack this and you could probably start fires.
Or create laser turrets that detect eyes and faces and immediately blind people in physical denial of service attacks.
I’ve been concerned about that scenario for about two years now. Didn’t say anything because I didn’t want to give anyone ideas, but oh well.
Don't worry there's all sorts of insanely nightmarish stuff nobody does because come on. (Also geneva convention.) But yeah when you have these nightmare ideas better not to share ;)
I believe someone has made a prototype before. It used to be a turret that fired paintballs.
> I have an unreasonable fear
No you don't, you have a very reasonable and justified fear of them. High powered lasers are scary for precisely the reasons you mention. I'd want to be very confident that there was a hard-wired fail-safe system which absolutely reliably shut it off before any harm could be done.
(Here's another scary scenario: Suppose the system and guard beams are working fine but someone puffs glitter into the air? Zap. Eyesight gone.)
No you don't, you have a very reasonable and justified fear of them. High powered lasers are scary for precisely the reasons you mention. I'd want to be very confident that there was a hard-wired fail-safe system which absolutely reliably shut it off before any harm could be done.
(Here's another scary scenario: Suppose the system and guard beams are working fine but someone puffs glitter into the air? Zap. Eyesight gone.)
It gets even better if the guard beam is a different frequency than the power delivery beam as the glitter could be transparent enough to the guard beam, but not transparent to the main beam.
They also don’t seem to be addressing the problem of the solar panel getting dirty/scratched and becoming more reflective. This is a much harder problem to solve correctly than a simple guard beam.
Disclaimer: I’m involved with a company making high power versions of this tech for industrial/military uses.
They also don’t seem to be addressing the problem of the solar panel getting dirty/scratched and becoming more reflective. This is a much harder problem to solve correctly than a simple guard beam.
Disclaimer: I’m involved with a company making high power versions of this tech for industrial/military uses.
>I would never be comfortable having an exposed, multi-watt laser in my living room.
Until the rest of the world has an exposed, multi-watt laser in their living room without incident, and then you'll be like "oh, guess it works."
Same with airplanes. "I'm never getting on that", until you see millions of people do it and live.
Until the rest of the world has an exposed, multi-watt laser in their living room without incident, and then you'll be like "oh, guess it works."
Same with airplanes. "I'm never getting on that", until you see millions of people do it and live.
Titanic, Apollo 1, bright white teeth, Fen-fen. Yeah, early adoption can be interesting. I'm a technophile, but we shouldn't turn a "blind eye" to its risks.
Also remember the risk of risk aversion: leading a dull, curmudgeonly life.
In general, I've found that the more you understand in detail how a technology works, the more comfortable with it you become.
In general, I've found that the more you understand in detail how a technology works, the more comfortable with it you become.
Perhaps, but this isn't a case of a technology that supersedes another in a meaningful way. Sure, plugging the phone in or placing it on a Qi charger is a hassle, but it is a working solution.
This isn't quite like the alleged cancer risk of cell phones: there's really no other technology that competes with cell phones at this point, so it is a bit easier to take on the risk.
This isn't quite like the alleged cancer risk of cell phones: there's really no other technology that competes with cell phones at this point, so it is a bit easier to take on the risk.
One of my secret weapons is the understanding that removing tiny bits of seemingly insignificant friction can have compounding effects, and ultimately results in qualitatively different outcomes.
Yeah, I guess we risk-averse types should just wait and see.
And continue to see, long after the early adopters can't.
this is a cool thing to build in the lab but I think will have just about zero real world practical uses.
interestingly enough there exists a small, but real market for power over fiber. usually used for things like electronic sensors embedded inside the fuel tanks of $50m+ aircraft. or in certain very sensitive parts of an oil/gas refinery.
basically a laser, a fat plastic fiber optic cable (way bigger than 62.5/125) not very dissimilar from TOSLINK type stuff, and a triple-junction GaAs concentrator-focused photovolatic cell, with the cell wired to a dc-dc converter.
https://www.fiberopticlink.com/products-item/power-over-fibe...
interestingly enough there exists a small, but real market for power over fiber. usually used for things like electronic sensors embedded inside the fuel tanks of $50m+ aircraft. or in certain very sensitive parts of an oil/gas refinery.
basically a laser, a fat plastic fiber optic cable (way bigger than 62.5/125) not very dissimilar from TOSLINK type stuff, and a triple-junction GaAs concentrator-focused photovolatic cell, with the cell wired to a dc-dc converter.
https://www.fiberopticlink.com/products-item/power-over-fibe...
I'm using a Qi charger instead which I put on the table. Ikea has them build in to tables, night stands, lamps http://www.ikea.com/us/en/catalog/categories/departments/wir... they are really safe because there is no laser involved.
I use Qi chargers as well, and they do work, but man... They would be so much better if they had even a few more millimeters of leeway in their positioning. As it is, each Qi device I have needs to be just so or it won't work. The fast wireless charger I got for my S8 is better than most, but still picky. I genuinely do think this needing to pay close attention to positioning is their biggest limitation to wider adoption.
(that, and android's insistence on turning on the screen to announce full charge, turning off, then turning back on again...)
(that, and android's insistence on turning on the screen to announce full charge, turning off, then turning back on again...)
I purchased one recently, and ended up sending it back the second time I woke up and found the phone to have <10% charge. I found because my phone is right next to my bed, the slightest nudge of the table it was on was often enough to misalign the phone (and it would usually start an endless cycle of charger recognised -> screen turns on because the phone thinks it's charging -> charging doesn't work -> connection broken, draining the battery in the process).
Definitely convenient, but also really finicky.
Definitely convenient, but also really finicky.
Apple's forthcoming qi charger mat is supposed to be less finicky than most, though it'll be quite expensive. Being super-fussy about positioning doesn't seem to be intrinsic to the technology, though.
> They would be so much better if they had even a few more millimeters of leeway in their positioning.
Well if resonant based charging can ultimately win the standards battle versus Qi (standard magnetic induction), then you could have some spatial freedom to move around and still get efficient charge. Qi has had first mover advantage in consumer electronics, while resonant charging seems to be taking hold in the wireless vehicle charging sector.
Disclaimer: I previously worked at WiTricity on their internal computational electromagnetic modeling tools.
Well if resonant based charging can ultimately win the standards battle versus Qi (standard magnetic induction), then you could have some spatial freedom to move around and still get efficient charge. Qi has had first mover advantage in consumer electronics, while resonant charging seems to be taking hold in the wireless vehicle charging sector.
Disclaimer: I previously worked at WiTricity on their internal computational electromagnetic modeling tools.
> They would be so much better if they had even a few more millimeters of leeway in their positioning.
Agreed.
Alternatively, maybe phone manufacturers can just stick a freaking magnet onto the phone and charger so that we can more easily feel where the proper positioning is. It doesn't need to be a strong magnet, it just needs to be enough so that I know where to center my phone without looking at the setup.
Agreed.
Alternatively, maybe phone manufacturers can just stick a freaking magnet onto the phone and charger so that we can more easily feel where the proper positioning is. It doesn't need to be a strong magnet, it just needs to be enough so that I know where to center my phone without looking at the setup.
I use Belkin's charging mat for iPhone X, and it's not picky about the location. Just putting it approximately centered is enough to start charging.
Do not look into the laser with the remaining eye
What was/is the name of the company claiming they can do that but have not produced any documentation proving it? Yet they have been collecting a substantial amount of investment.
You mean the possibly longest running joke of Silicon Valley? That's uBeam, but they're the ultrasound people.
Ossia demoed this type of tech at CES this year. I believe they have a very solid offering.
Source - my colleague works there.
https://www.ossia.com
Source - my colleague works there.
https://www.ossia.com
https not working for me, http did though
Woops, thanks - typed it by hand and made the assumption. Going to tell my buddy to have that fixed!
We could do this with cars: Laserroadways
Nice demo but way too complex and limited (requires line-of-sight) for practical use. I would rather take a MagSafe-style zero-force dock.
Definitely. Especially since in either case, you have to put the device in a predetermined place.
> the emitter could be aimed at a wider charging surface, such as a counter or tabletop, and charge a smartphone placed anywhere on that surface.
And because in order to notice that the device is there, they have to also make it emit chirps
> The researchers programmed the smartphone to signal its location by emitting high-frequency acoustic "chirps." These are inaudible to our ears, but sensitive enough for small microphones on the laser emitter to pick up.
End result: a phone that chirps all the time (you can't hear it, but maybe your dog is annoyed or your security system is triggered), in order to let the charging system notice that it's sitting in a predetermined location, so that it can fire a laser at it, which needs safeguards to keep from hurting you. Also this method is apparently inefficient, given that they need a heatsink for the laser.
How about no chirping, no lasers, and we just make plugs that are easy to use? (The old round barrel-style plug on my ancient flip phone was easy to plug in, even in the dark.)
> the emitter could be aimed at a wider charging surface, such as a counter or tabletop, and charge a smartphone placed anywhere on that surface.
And because in order to notice that the device is there, they have to also make it emit chirps
> The researchers programmed the smartphone to signal its location by emitting high-frequency acoustic "chirps." These are inaudible to our ears, but sensitive enough for small microphones on the laser emitter to pick up.
End result: a phone that chirps all the time (you can't hear it, but maybe your dog is annoyed or your security system is triggered), in order to let the charging system notice that it's sitting in a predetermined location, so that it can fire a laser at it, which needs safeguards to keep from hurting you. Also this method is apparently inefficient, given that they need a heatsink for the laser.
How about no chirping, no lasers, and we just make plugs that are easy to use? (The old round barrel-style plug on my ancient flip phone was easy to plug in, even in the dark.)
There are lightbulbs that form mesh networks using lasers. I forget the name but I recall it being on HN last year so it must be true! A quick googling finds something similar https://techcrunch.com/2015/09/14/linux-light-bulbs-allow-de...
If lightbulbs can provide wireless power to devices in the room that would be awesome and have practical applications even if it can't charge something as power-hungry as a phone very quickly.
If lightbulbs can provide wireless power to devices in the room that would be awesome and have practical applications even if it can't charge something as power-hungry as a phone very quickly.
Lightbulbs already do this: solar panels work perfectly well under bulbs of many type.
Typical 5 watt solar panel is 25x25 cm. That 5 watt is generated under ideal conditions, i.e. in sunlight, measuring about 100 kilolux. Bright indoor lightning is 1 kilolux, i.e. the "indoor solar panel charger" would take ~6 m² (assuming ideal spectrum).
They don't use lasers.
I can't believe true effortless phone charging still isn't solved. The capacity of a phone battery is about 8 Wh, which would mean that an "ambient" charging solution in a bedroom would need to provide 1W of charging to be feasible. We already know that we can put decent antennas for microwaves inside phones at low cost (e.g. WiFi), so what's needed is some form of tracking beamforming from the transmitter to get reasonable efficiency. Even if only 10% efficiency can be achieved, that should be a viable product (leaving aside the moral/environmental aspect of energy waste).
I guess part of the reason why it doesn't exist is non-technical hurdles, FCC and radiation fears.
I guess part of the reason why it doesn't exist is non-technical hurdles, FCC and radiation fears.
I see what you're saying. We all want to improve technology here right. But I don't find it a great deal of effort to leave my phone on a charging mat when I go bed already. I think we're already at an efficient cost of effort over financial cost of an even more effortless technology already.
First off, I'm not saying I want this tech, I'm saying it would do well in the marketplace if it existed. Second, the 'effort' is not the physical act of plugging in, but rather the mental act of remembering to. Plus the potentially huge downside of running out of battery in a precarious situation.
for me, it’s not about when i go to bed. that part’s easy already; it’s about when you’re at a friends house, or work, etc for longer than you expect and your battery starts to go flat. in this case, you think “i should have just charged my phone; i was next to a USB port all day”. it totally eliminates these situations once lightbulbs with charging become common place because you just show up and your phone starts charging without thinking about it
It's very likely that the low-tech alternative just catches up way sooner than the (objectively better) high tech solution becomes viable.
The low tech in this case is that your friend probably has a compatible charger, and it's probably even already lying around so you can just plug in without even breaking conversation.
(There are a number of incompatible standards out there, but wireless charging would also be beset by competing standards)
The low tech in this case is that your friend probably has a compatible charger, and it's probably even already lying around so you can just plug in without even breaking conversation.
(There are a number of incompatible standards out there, but wireless charging would also be beset by competing standards)
Really there are only three standards I can think of - micro usb, covering probably 80%+ of devices, whatever the current becoming popular. That's way better than it used to be.
I suspect ubiquitous charge pads will get us most of the way there a long time before any sort of long distance wireless (especially if e.g. the EU mandate a single charging standard as they did with micro USB). If they are everywhere, it's relatively easy to remember to put your device there, and forgetting to do so doesn't matter most of the time if/when you can get a meaningful amount of charge in just a few minutes.
Even just wireless contact charging. Battery life isn't a real issue on phones these days, as long as you plug it in when it's not in use.
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Having had a brief working experience in a lab involving high-powered lasers, I have an unreasonable fear of these things. A random beam reflection can hurt your eyes in a painless way. You only notice the damage later when things start disappearing from your field of view (similarly to how you're not normally aware of your natural blind spot). I've been told that everyone that retires from that field of research has had holes burned into their retinas despite strict safety procedures.