There's noway that this is going to be practical within the current laws of physics. You can't use a wide beam to cover an area because the amount of energy available drops by orders of magnitude the further you get from the transmitter. If you used a focussed beam (which is what they are suggesting) then you need a separate beam that tracks and follows the location of each device. So to cover a very small area you'd need multiple transmitters tracking and beaming sound to the exact location of each device. And the transmitters are going to have to be very close by, and then there are all the obstacles between your pocket and the transmitter that will block the beam. You might as well just use an inductive charger. But still, just like solar freaking roadways and perpetual motion machines we want to believe and since most people don't understand the science these ridiculous and impossible ideas draw people in again and again.
Well, in principle you can divide one transmitter's attention to several devices over time. (Either by changing the direction of the antenna, or more sophisticatedly via beamforming.)
Otherwise I agree with you. Even the tone of this article is unconvincing. I wonder what Andreessen’s due diligence team was thinking, maybe the patents have value?
If I were a VC invested in this, I'd want hearing tests on the engineers working on this project; once a month, over time.
Of course, if I were a VC, I wouldn't invest in this, because it is physically retarded on inspection. Whoever did the dil on this is either a fool who doesn't understand basic physics, or was bribed somehow. Off the top of my head
a) sound energy falls off as 1/r^2,
b) that those sorts of energy densities are almost certainly physically dangerous to more than ears
c) sound doesn't propagate well in air at those frequencies; you're basically heating up air
d) transducers are not good at turning sound into energy
No, it doesn't. That's how it falls off when being transmitted perfectly spherically in an environment that won't reflect or refract anything. Consequently, this turns out to be a not-very-useful equation in practice. In particular ultrasound can be beamed just like light, making the "perfectly spherical transmission" not even a close approximation, just as it is not a good approximation for focused lasers. Our intuition doesn't support this because our hearing tops out at frequencies still low enough to do some significant bending around obstacles (though at the higher end if you pay attention you can tell they don't do it as well), so we don't have an intuition of sound acting like a beam, but it can.
There's more to sound than "basic physics", and what you learn in Physics 101 about sound is simplified to the point of total uselessness as in real-life you will never encounter a situation where the prerequisites are met for inverse square falloff.
Mind you, I'm still pretty skeptical, but not about the ability to beam sound. That's established engineering, not wild-eyed craziness.
OK, since conversation has moved on, let me be blunt: You don't know what you're talking about. Your physics 101 education is not the end-all, be-all of physics, and what "point" transmission does doesn't matter because we aren't talking about points. You are in no position to be lecturing people about physics; you are in a position to be lectured to about physics.
With electromagnetism the energy fall off depends on the radius and the wavelength. If the wavelength is is greater than a certain amount of the radius (the Fraunhofer distance) then the energy fall off is a linear 1/r. This is called the near field.
Sound which you can't hear isn't going to be dangerous to the ears in a conventional sense. Of course at electrically significant power levels, it is just potentially dangerous generally.
Ultrasound can also cause tissue damage at high intensity.
I'd be cautious about making claims that humans are not damaged by high intensity sound, even if inaudible.
Perhaps this is what you mean by saying "a conventional sense" but I just thought I'd expand on your answer in case others read it and get the wrong idea.
>The problem I can see is that the filing date for those patents is far later than public demonstrations such as the one at D9 on or around 04/22/2012
That would indeed cause a problem in a country with an "absolute novelty" requirement in patent applications, but the United States is not a such a country. In the US, the inventor has 12 months after the first public demonstration to file for a patent, and in this case, the patent was filed within 12 months.
> I wonder what Andreessen’s due diligence team was thinking, maybe the patents have value?
The job of a VC is to sell to later investors. Long term viabilty isn't always in their best interest. I could name half a dozen specifics but I'll let you imagine instead.
(from the article) >Did the physics actually work? Check
I apologize if this question is terribly ignorant, but do investors publicly disclose the results of due diligence that would lead them to believe in the functionality and practicality of such a product? I'm very interested in learning their opinions on the challenges presented by the naysayers (with whom I agree right now).
I appreciate everyone who provided sources that prove uBeam has, at the very least, some huge challenges to overcome in practicality. Like you mention, though, I imagine that these investors have probably considered these challenges.
As far as I know the circulation of DD reports is extremely limited, usually to the company paying for the report and occasionally the management of the company that was looked at.
In the case of outright BS it stays with the VC, if there are useful 'to-fix' prior to closing items then they usually get passed (sometimes edited or excerpted) to the company.
A general public disclosure is a possibility but I've never seen one, investors are not 'speaking for the company' in any way and if investors started to release such sensitive documents that would be considered a false step by the company (and probably rightly so, the information gathered during the process is company confidential and no VC in their right mind would want to suggest to future investments that they have a cavalier attitude towards such information, be it positive or negative, disclosure should be up to the officers of the company).
Meredith Perry is no fraud. She was in a Penn graduate program before this venture, and has worked at NASA.
It's directional transmission technology. The power loss is minimized as the ultrasound is directed and focused at a particular location. There's no inverse square law here, and it's easily within the bound of known physics.
As far as I know, (indirect relationship with the a good friend of the founder, that I won't say anything more about to protect his privacy) Meredith is actually genius-level and a relentless work horse. I'd bet big on this one.
If I could work for any one company it would be uBeam. I just started a great position, and I'd do it despite the press. The moment they made an offer I'd be on a plane.
This is a "First they dismiss you. Then they laugh at you. Then you win" scenario.
I don't care how smart she is, she can't defy the laws of physics. Also, the reflection and harmonics are going to drive any animals and/or children & teenagers nuts.
She's not defying the laws of physics. It's a tracked directional system that concentrates the ultrasound at the point of the device. Honestly, not even really that out there as far as the physics is concerned.
EDIT: Unlikely. Children hear better in upper ranges, not lower. And animals are unlikely to be too perturbed. These types of noises are generated naturally all the time.
The challenge here is the engineering. How precisely can you build the tracking? How much leakage is there? Are there problems with harmonics? How do you build an app that can relatively reliably 3d position a device relative to a base station. And finally, how do you get that base station to be able to simultaneously or rapidly re-aim itself to target each of the devices. That's hard, but certainly exciting and very possible.
The patent application[1] lists the transmission frequency as 40-60kHz, a high frequency. Humans typically hear up to around 20kHz, dogs 44kHz, cats 79kHz. Not Low frequencies.
A directed, concentrated, high decibel volume, in the 40-60kHz range is not the sort of thing found naturally 'all of the time.' As other posters have mentioned, transmitting energy via sound is likely impossible do both safely and at useful amperage. Ultrasound is not safe at high energies even if you can't hear it.
Given that the patent followed a prototype, it has to in some way resemble the final tech.
The fact remains that Ultrasound is not an efficient mode of energy transmission [1]. Wireless induction is almost certainly more efficient over the same distances. And ultrasound is a potential nuisance and hazard to wildlife and pets in way EM broadcasts simply aren't.
I am skeptical of the claimed safety of uBeam. The FDA does not advocate the safety of ultrasound.
From the article: "Was it safe? Well … for starters it is just an inaudible soundwave being transferred – as in the kind also used for women during pregnancy."
From the FDA: "Even though there are no known risks of ultrasound imaging, it can produce effects on the body. When ultrasound enters the body, it heats the tissues slightly. In some cases, it can also produce small pockets of gas in body fluids or tissues (cavitation). The long-term effects of tissue heating and cavitation are not known. Because of the particular concern for fetal exposures, national and international organizations have advocated prudent use of ultrasound imaging. Furthermore, the use of diagnostic ultrasound for non-medical purposes such as fetal keepsake videos has been discouraged."[0]
A giant 0.1 m^2 tablet charging at 12W (120 W/m^2) needs only a 140 dB field. A watch, which might need 1W but with a cross section of more like .001 m^2 (for 1000 W/m^2), needs a 150 dB field.
If something intercepts the beam at 1m instead of the 3m the device is charging at, the cross section of the beam is about 1/3 by 1/3 the final cross section, which since it has to have the same energy (actually would need more to compensate for attenuation through air) would be nearly a 10dB increase?
Is 160dB of ultrasound (at 40kHz or 110 kHz) safe... for a few seconds? for a few minutes? a few seconds of exposure, daily? To your eardrum? To your eyes?
Higher energies needed if the phone isn't perfectly oriented. Worse case is small edge-on orientation to the transmitter.
Higher energies needed for less than 100% transducer efficiency, and I don't know what kind of engineering magic they've done for the transducer but what percentage of the energy could a thin skin over a device possibly convert? 80%? 50%?
The beam could be 170dB, or more.
I want to believe, but this is too sketchy without more information. Large companies have been conned out of millions by small teams peddling snake oil. I'd first want to see it demonstrated with nothing but the transmitter plugged into a socket (through a power meter), a phone at a known, low battery level, and nothing else with wires or metal in the room. Then I'd like to see a test of the transmitter aimed (from above) at a glass of water with a visible thermometer, to see what it does to water.
I use "inaudible soundwaves" on a daily basis to turn cells into formless goo. It's so destructive that we generally only use it for really tough things like bacteria.
Ultrasound is also really good at chopping up DNA into little fragments.
Granted, this is for 10s-100s of watts, but I still avoid putting my fingers into the low power sonic bath... cargo-cult superstition dies hard.
That quote from the FDA is referring to ultrasound imaging, which is performed with transducers in direct contact with the body. Even in those instances, ultrasound is regarded as one of the safest medical imaging techniques.
Nonetheless, while I suspect this technology is safe, I agree they shouldn't hand-wave over that aspect.
Medical ultrasound imaging uses far higher frequencies than the patents for uBeam claim, so they can't be compared. And even medical ultrasound isn't fully safe, there are some indications of brain damage in mouse models after long exposure to ultrasound.
The back story of this company is intriguing. The founders presented a prototype way back in 2011 at the D9 conference[1], and apparently weren't able to get any traction until they found a believer in Scott Nolan at Founders Fund[2]. Interestingly, Nolan seemed most impressed by the company's distribution plans:
> Mr. Nolan said Ms. Perry had shown that chain stores and some “quick-service restaurants” were eager to integrate a wireless charger into their plans. She “had addressed all these key risks and got them nailed down early,” he said.
To me, it's not surprising that folks would be excited by the concept of wireless charging, just as you could easily find plenty of people who would tell you they'd buy a Back to the Future-style hover board if you could actually build it.
The big question is whether the technology is real and commercially viable. One physicist who has worked on wireless charging applications says he reviewed uBeam's patent applications and ran the numbers. His conclusion: it isn't[3].
I don't know who keeps that [3] blog or his credentials, but as an admitted appeal to authority, the CTO of uBeam (dual BS & MS from MIT) also ran some numbers before joining the company. As did Andreessen Horowitz's due diligence team before investing, which I'd imagine has a physicist or two in waiting.
One obvious shortcoming in [3]'s analysis is assuming that you'd still need 5W of charging power if you could wirelessly charge. Delivering 1/50th of that power is probably enough to maintain a charge throughout the day and people spend ~95% of their time in reliable locations that could support wireless charging (home, car, office, etc.)
the CTO of uBeam (dual BS & MS from MIT) also ran
some numbers before joining the company
I would hope that the CTO of uBeam essentially is the reason the company exists. i.e. he invented something fundamentally new and needed a partner that could sell it. If the business started with a charismatic business founder that recruited the CTO based on the business model being sound, I'd be very skeptical. A business like this doesn't exist yet not because the business model is hard, but because the physics is.
I only expect they make other people choose when they are around to have this on.
We used to do lots of experiments in the lab with ultrasonics, playing around. A couple of times we had our ears hurt for a while(all the people in the team) after getting out of the lab, We learned the lesson, even when you don't hear anything, it can affect you.
In fact, it is worse when you can't detect something that could affect you.
I would prefer to use something that I could see like visible green light and solar cells in the phone. I won't put my eyes too near of a 10Watts source, but with something you can't see or hear, you could inadvertently put your organs too close for too long.
The frequency range they list in examples for applications are from 40kHz to 110kHz. This actually does overlap with the hearing ranges of dogs and cats somewhat. Wiki lists the dog hearing range from 40Hz to 60kHz and the cat range from 55Hz to 79kHz.
Humans should be safe though since a common number for the high-end of human hearing is 20kHz.
>Humans should be safe though since a common number for the high-end of human hearing is 20kHz.
That doesn't mean it's safe for humans, it just means it's inaudible to humans. In many circumstances, an imperceivable threat is far more dangerous than a perceivable one. Laser is one example. If a visible laser beam hits your eyes, your blink reflex will kick in and (hopefully) save you in time. But a laser beam outside the human visual spectrum will literally burn your retina out before you figure out what's going on.
> Was it safe? Well … for starters it is just an inaudible soundwave being transferred – as in the kind also used for women during pregnancy. It also happens to be how your car likely tells the distance to objects when you park or if you have a side assist whether you can change lanes safely. Check.
Both of those Examples involve short exposure. That doesn't necessarily mean long exposure is OK. You would not, I hope, conclude for instance that an X-Ray based system is safe because dentists X-Ray people as part of an annual check up.
I expect it to turn out safe, but I'd want to see some studies first.
Also, I'd like to see studies on what affect it has on pets. Will it also be inaudible to dogs? If not, that needs to be documented so that dog owners won't unknowing torture their pets.
That's got to be a pretty loud noise to be able to transfer enough power to a device at a distance to be significant. Can long term exposure to loud ultrasonic noises damage your hearing even if you can't "hear" them somewhat like the way IR light can damage your eyes even though you can't see it?
Think I might let a different set of early adopters try this one out before I put one in my bedroom to charge my iPad. It may just be ignorance (knowing just about nothing when it comes to acoustics) on my part, but I'm way more afraid of this than inductive wireless charging.
I would think so, even if not currently measurable. Infrasonics which is sound on the other end of the inaudible spectrum is the phenomenon where animals know when an earthquake is coming, or when rats know to leave a sinking ship http://en.wikipedia.org/wiki/Infrasound
I'm not an expert in this field though.
One problem with using ultrasound for anything is that interference between two ultrasound sources and ultrasound and 'regular' (audible) sound can be audible itself.
This is interesting technology (and not exactly new technology either), but less than practical when deployed with the same carelessness with which WiFi base stations are strung up (and extension cords are deployed).
Ultrasound may not be heard directly but that doesn't mean it doesn't affect you either. Unlike magnetism (of which we can be exposed so serious field-strengths before it starts to affect us) ultrasound, especially high power versions (you're going to have to do this at a fairly high power level if you're going to be beaming the power indiscriminately, if you want to 'focus' on a receiver then you're going to have to take all kinds of losses from less than ideal angles and distances into account which really adds up) can cause you to experience sensations even when you can't experience the soundwave itself.
Nice idea, probably won't fly but I'm rooting for them anyway and I hope Andreessen and co had this properly vetted for all of the above before they invested (I can't imagine them doing otherwise but VCs are not above making stupid investments). They indicate several times they did plenty of DD so who knows, it might just really work and have no side effects whatsoever.
Meanwhile, I'll be plugging my cellphone into its charger and call it 'good enough', once every 5 days is a minor inconvenience.
Wow, I didn't expect this level of skepticism and negativity on hacker news. This is exactly the kind of audacious, potentially world changing invention that hackers should be striving for. Merideth has my respect. We should be supporting her in this endeavor, not trying to tear her down.
I was really hoping there was more hear about the technology, specifically what they are doing differently and the backgrounds of the engineers making this a reality. The process of raising money and getting buy-in is far less interesting than demos showing how much electricity is going into the transmitter and how much is being received by the receivers, especially under the conditions he says they can deal with (movement, etc). This is one of those ideas that fails or succeeds on the technology. As background, talent, gumption and charisma of the non-technical people is irrelevant if the technology isn't there.
It's a very strong sell from a VC without evidence. If they can do some of the things claimed, wouldn't you let the evidence speak for itself?
Exactly. They just raised $10 million. Why do they need any selling at all? Obviously they should be back at work building their product and figuring out the manufacturing logistics for when it's ready. Hyping a company right after raising a round and way before they have a product is strange.
Only thing is that I want to see what's in the box on the left. There's nothing to show that the transmitters are actually transferring power and aren't simply telling the other side to turn on and change resistivity to a hidden battery on the left hand side (or even draw from the battery in the iPhone connected to the left hand side)
Furthermore, that's a pretty janky analog multimeter to be using for anyone doing electronics, and it's currently set to measure resistivity, not current or voltage.
Current or voltage is not relevant you want current and voltage. Just voltage without Ri doesn't mean anything, you could easily get any kind of voltage by using a simple transformer. That doesn't mean useful power is transferred for that you need to apply a load and measure current through the load and voltage across the load.
Also, AC voltage on an analogue meter is usually calibrated at 50 or 60 Hz, not at much higher frequencies.
So it is. I tried to find a big picture of that multimeter to see what it was set to because the video image quality it poor, but now on closer inspection I can see it's set to AC volts. The most similar analog radio shack model I could find a picture of extended the resistance area further up the dial.
I cannot judge the merit of this approach but I have been eagerly waiting for WiTricity or Cota to show up in my electronics gadgets. Can't wait to get rid of charging cables. I am sure the engineering takes lots of effort and time but I remember seeing WiTricity TED talk years back :(
I was expecting Apple to integrate such technology for it's Watch. I don't want one more device that I have to remember to charge everyday.
Tesla drove himself crazy trying to transmit power wirelessly.
Physics and nature make it hard to safely transfer a large amount of energy between a source and our bodies. Wide beam = loss. Narrow beam = destroying human flesh.
Wireless anything has a reality distortion field around it.
This plan seems like it is bulging with "almosts."
I don't think it will go widespread, but it will be a valuable niche. Kind of like google glass and segways. Their job is to find that niche. Perhaps in a laboratory or food processing factory setting? or another manufacturing environment where a machine or robot must operate wirelessly.
I can't see how this would be efficient enough to charge a phone. Does anyone have a rough idea of what the end to end efficiency of this system would be?
Also if it's a beamed technology, does it then need N transmitters to charge N devices? How is the beam targeted?
Seems like a simple inductive charger would be much more practical.
Plugging stuff into the wall isn't all that cumbersome. I'm not sure why I'd even want something like this. Not trying to be a troll, just really missing the appeal on this.
I concur with you. VCs have a hard time measuring technical knowledge because they lack such knowledge themselves, and first appearances are more the result of the generic lottery than skills. That doesn't mean every rich person is beautiful, but it would be dishonest to pretend that it doesn't play a big role when social interactions are involved, such as raising capital.
There's a more in depth analysis of why this won't work here: http://www.eevblog.com/2014/08/07/ubeam-ultrasonic-wireless-...