
UBeam's Meredith Perry shows her wireless charging technology really works - daegloe
https://www.usatoday.com/story/tech/news/2017/06/01/ubeams-meredith-perry-shows-her-stealth-wireless-charging-technology-really-works/102336880/
======
w1ntermute
Analysis of the article by former uBeam VP of Engineering Paul Reynolds:

> In all this time, have reporters still not learned to press on the key
> questions? "How much power is being received?", "How much is being sent?",
> "What's the efficiency?", "How much does it cost?", "Have you proved it
> safe?", and "If this is what you have now, what were all those 'prototypes'
> you were talking about 2 years ago?". But those are actual questions that
> matter, and basically we know the same today as we did yesterday (which
> indicates it was an awesome PR piece, lots of coverage with no actual info).

[http://liesandstartuppr.blogspot.com/2017/05/whats-in-
pictur...](http://liesandstartuppr.blogspot.com/2017/05/whats-in-picture.html)

[http://liesandstartuppr.blogspot.com/2017/06/someone-was-
pay...](http://liesandstartuppr.blogspot.com/2017/06/someone-was-paying-
attention.html)

[http://liesandstartuppr.blogspot.com/2017/06/what-does-it-
ta...](http://liesandstartuppr.blogspot.com/2017/06/what-does-it-take-to-
switch-phone.html)

~~~
averagewall
For safety, the transmitter could turn itself off if a receiver isn't
receiving enough power. The receiver could radio back to the transmitter to
identify its presence and power input.

~~~
aisofteng
Have you considered sending the engineering team thoughts like these, or any
other offhand ones?

~~~
logicallee
You were downvoted, and my interpretation is that people thought you were
sarcastic and thought that this was an inappropriate jab, and downvoted for
this reason.

I think they're right that you're being sarcastic, due to the word "offhand".

However, if we read your comment seriously (you are seriously stating it) then
I actually agree with it: this means the "wrong" part of your comment is the
/s (which you didn't include) and otherwise your comment is very solid.

I'd like to defend it.

Here are just some of the off-hand ideas that were demonstrated in this video:

\- Beam forming

\- Vision for device tracking. (VISION!!! DO YOU HAVE ANY IDEA HOW OFF-HAND OF
AN IDEA THIS IS?)

\- Inclusion built into every manufactured phone and uBeam beamers located all
over the place, so that even a trickle ends up recharging the phone
"throughout the course of a day" \-- assuming you aren't actually using it.

\- Have it be something you don't even notice. (So that for this reason it
doesn't matter if it barely works). ie if you have your phone in your pocket
for an hour while you sit and talk to your friend, it goes from 51% to 83%
charge. That is a good and viable definition of "don't even notice it."

These are extremely off-hand ideas. It is extremely possible that adding a
dozen other extremely off-hand ideas are all that it would take to make this a
viable, pervasive technology, built into everything.

For example, it was demonstrated on a huge receiver that is much larger than
the phone it was attached to. A couple of off-hand ideas about how to make the
receiver smaller might be all it takes to make this more interesting.

There are further possible off-hand ideas. add in about a dozen and, if they
have appropriate patents, they have a monopoly on a charging solution.

When you have a choice of two cafes across the street, and if you spend an
hour in one of them your battery will be 10% more charged than before you
entered, would you choose that one over the other one?

You would if you were at 1% battery level and waiting for an important client.

Bam. You've just made a case that this brings free users to cafes as a direct
competitive advantage, much like having wifi might.

And what was this -- oh, right: an off-hand marketing idea I just had.

Don't dismiss off-hand ideas.

If you like, it's all Steve Jobs ever contributed. Send them - send them all.
You might end up making uBeam work.

Note: I have no association with the company or any horse in this game.

~~~
alphakappa
>>>Don't dismiss off-hand ideas. If you like, it's all Steve Jobs ever
contributed.

That's the most offhand description of what Steve Jobs contributed that I've
heard. Let's not minimize the contributions of people when we have no idea
what went into making them successful.

~~~
logicallee
You entirely missed my point. individually, any of his contributions can be
thought of as an off-hand idea taken to its logical conclusion and actually
implemented, but jointly they make success.

------
Animats
The picture shows a 32 x 32 array of small ultrasonic emitters. So that's 1024
emitters. The framed area is about 200mm square, so each emitter has a
diameter of about 6mm. That's unusually small; typical diameters are 9mm to
20mm. I haven't been able to find the source of that transducer, but a similar
one 9mm across is here.[1]

That one can deliver 112dB sound pressure at 30cm range. 1000 of those would
deliver 142dB at 40KHz. (10x = 10dB). If they're all wired to one amp, you get
a straight beam. The demo indicates they're only getting a straight beam;
steering the beam requires electronics behind each transducer. Quite possible,
but runs up the cost. If they wire up the transducers in rings and drive them
with slightly different phases, they can tighten up the beam focus. Since the
receiver is smaller than the transmitter, focusing would help. Frequency is
probably around 40KHz; if you go higher, losses in air go way up.

I haven't worked out the drive power for this thing, but it's probably a few
watts per transducer, or a few kilowatts for the whole array.

So they have a 142dBA 40Khz beam about 200mm square. They ought to be able to
do some short-range charging with it.

Notes:

* That's a high-powered ultrasonic beam. Is it hazardous? Most of the literature on ultrasonic safety involves energy coupled directly to skin, as with ultrasonic scanning, where there's a gel to improve transmission. Generating high energy in air is rarely done. It's certainly going to heat up anything in the beam. The safety issue is a big deal. All that energy has to go somewhere.

* How far can they project this? At 40KHz, meters, maybe tens of meters.[2] Attenuation gets much worse with frequency, so this thing probably works in the low ultrasonic range. Early PR from UBeam talked about megahertz ultrasound, but the range would be a few millimeters up there.

* Efficiency is terrible. Kilowatts in, watts out.

* That array of transducers isn't cheap. Those things are usually a few dollars each. But in quantity, that could come down.

So the demo they did, at under 1m range, is possible, but doesn't mean it's a
useful technology.

[1]
[https://www.americanpiezo.com/images/stories/content_images/...](https://www.americanpiezo.com/images/stories/content_images/pdf/apc_10-3005.pdf)
[2]
[http://www.kayelaby.npl.co.uk/general_physics/2_4/2_4_1.html](http://www.kayelaby.npl.co.uk/general_physics/2_4/2_4_1.html)

~~~
jacquesm
> Kilowatts in, watts out.

Probably milliwatts out, you have the conversion efficiency _twice_ , once
when you convert from electricity to ultrasound and then the reverse, where
the reverse conversion gets the interference of the wave-fronts of all the
sound waves emitted by all the transducers at the source all mixed up. It's
not going to arrive as a nicely coherent wavefront.

That really is not going to help, and any losses to heating the air also need
to be factored in.

Chances are the uBeam will end up pivoting to an ultrasonic heating system for
coffeeshops.

Also, where do you see the 32x32 array?

Is it this pic?

[https://www.gannett-
cdn.com/-mm-/6e692618ead22efd1bb5f481476...](https://www.gannett-
cdn.com/-mm-/6e692618ead22efd1bb5f481476a66d82c39266a/c=58-0-966-683&r=x404&c=534x401/local/-/media/2017/05/31/USATODAY/USATODAY/636318369992673051-mp.JPG)

To me that shows a 10x10 array of much larger transducers.

The other device (the white ceiling tile) shows 7 hexagonal arrays each with
144 transducers, that works out to almost 32x32 for all 7 but they may be
steering the beams to different phones from different arrays (they claim up to
5 phones) so it may be that only one such blade is active for a phone. And the
total size of that array is much larger than 200 mm square.

~~~
Animats
The still frame from the video in the original article shows an aluminum frame
with what appears to be a 32 x 32 transducer array. I'd assumed that was a
tightly packed array of off-the-shelf aluminum ultrasonic transducers. Like
this one from another sensor project.[2] It's common to build arrays like that
as sensor devices; you can steer the beam on both transmit and receive. One of
those is shown here.[1]

It's hard to tell; not enough resolution. Maybe that's just a grille over
something else.

It would be straightforward to do this with microwaves. Transmitting from a
microwave source to a rectenna works fine.[3] Efficiency has passed 50%. The
solar powersat people have been fooling around with this for decades. But even
a few watts of microwave power indoors is a safety concern.

What scares me about this thing is the claim that kilowatt levels of
ultrasound are safe. Power levels like that are used to weld plastic.

[1]
[https://www.youtube.com/watch?v=Qxd7VYujMgQ](https://www.youtube.com/watch?v=Qxd7VYujMgQ)
[2] [http://dm.ncl.ac.uk/benfreeth/2010/07/23/parametric-
speaker/](http://dm.ncl.ac.uk/benfreeth/2010/07/23/parametric-speaker/) [3]
[https://phys.org/news/2015-03-japan-space-scientists-
wireles...](https://phys.org/news/2015-03-japan-space-scientists-wireless-
energy.html)

~~~
jacquesm
> The still frame from the video in the original article shows an aluminum
> frame with what appears to be a 32 x 32 transducer array.

I thought that was the cover in front of that 7 petal arrangement.

> I'd assumed that was a tightly packed array of off-the-shelf aluminum
> ultrasonic transducers.

Ok, could be. But to me it looks like a cover over this:

[http://liesandstartuppr.blogspot.nl/2017/05/whats-in-
picture...](http://liesandstartuppr.blogspot.nl/2017/05/whats-in-picture.html)

No contest about the microwaves, that would work just fine (it would also cook
everything in its path).

> Power levels like that are used to weld plastic.

Yep. Ultrasound friction welding of PVC.

There is an article linked below that claims 53% efficiency for ultrasound
energy transmission at 1 meter.

~~~
Animats
It's hard to tell what they're showing. The Blogspot article points out that
they used a blur filter to hide the details of the sonar array. He thinks
they're using Murata ultrasonic transducers. (Those were popular in the Stone
Age of mobile robotics.[1])

I dunno. There's too much obfuscation here. Are there any high-resolution
pictures of the transducer array with the cover off?

[1] [http://www.robotshop.com/en/ultrasonic-range-
finders.html](http://www.robotshop.com/en/ultrasonic-range-finders.html)

~~~
jacquesm
There are several frames in that embedded video that are usable, that's where
I counted the transducers and their arrangement.

At 0:54

------
jacquesm
Umm, not to be really nasty but did they do a teardown of those sleeves?

You can buy a new phone but if you slip it into a sleeve that size then that
still affords plenty of room for a rigged demo. (Sorry, professional
deformation at work here.)

What would be far better proof that it works is a simple caloric setup showing
how much power is transferred per unit time at which distances and angles from
the transducer tile.

Also, where do the optical lasers come in? To find a target to steer beams to
using phased arrays of transducers?

If so that would imply only line-of-sight.

edit: so yes, the article confirms line of sight only and very low levels of
power delivery

~~~
ChuckMcM
I wouldn't want to be in that office on 'bring your dog to work' day :-)

I find these stories fascinating not by what they say about the technology but
more what they say about the state of education in engineering these days and
the ability to believe the impossible is possible. I wonder sometimes if
someone told these people "if you can imagine it, you can BUILD it!" and they
took that statement literally.

There has been a tremendous amount of work in energy harvesting from ambient
sources which is really pretty amazing. There was a fun paper on harvesting
sound for energy in 2013 [1]. The key of course is how much energy and at what
efficiency.

The CEO's point was that if you can charge anywhere you don't need a full
charge, you just top off. It would be interesting to see if it can charge
while being used (so net positive charge). In the video at least you can see
their device for showing the beam footprint.

I'm also wondering "why talk now?" clearly burned by previous skepticism, why
not just wait until you have a fully realized product or are they doing a fund
raising round and need some outside validation after their disastrous first
go?

[1]
[http://www.enggjournals.com/ijet/docs/IJET13-05-06-118.pdf](http://www.enggjournals.com/ijet/docs/IJET13-05-06-118.pdf)

~~~
gene-h
You can actually buy commercial products that are powered by sound. Sound is
actually a pretty great power source for wireless sensor nodes that monitor
loud pieces of machinery. Sure, you don't get much power, but for a sensor
node you don't need much either. Sometimes sound is the only source of power
you can get for such things where it's too dark or parts need to move relative
to each making wires difficult. Plus, sometimes you want to monitor the very
same vibration that's giving your sensor power.

Now the thing that really gets me is some work I saw on developing a vibration
powered sensor for highway bridges. So the best power source they found was a
small wind turbine. But when they tried them out on a bridge out in the middle
of nowhere, the problem was they were just too much of an entertaining object
for people to shoot. So they made this rather large pipe with a magnet on
springs inside and were able to harvest energy from the low frequency
vibrations of the bridge moving around.

[0][https://www.microgensystems.com/](https://www.microgensystems.com/)
[1][http://www.ni.com/white-paper/12128/en/](http://www.ni.com/white-
paper/12128/en/)

~~~
jacquesm
There even was a company that tried to produce windpower based on that
principle (windbelt).

------
brians
The reporters didn't see a tear down of the sleeves, and wouldn't be able to
identify a battery if they had. They showed sleeves and a charging indicator,
rather than a simple wattmeter. This was a fraud—though like many inventors of
perpetual motion machines, it is plausible Perry first fooled herself that the
battery in the sleeve is just "to cover the initial surge" or "until we can
fix this efficiency problem."

The important lesson here is that USA Today and similar papers can be fooled
by a rigged demo and a sincere voice. Read the front page with similar
skepticism!

~~~
lern_too_spel
It would require a lot of engineering work just to fake a demo to have a
battery that charges when the sleeve is in the beam and doesn't when it isn't
or the beam is blocked. More likely, there is actual power transmitted and
received but not enough to charge the battery when the phone is doing anything
at all. The charging indicator will turn on if you're putting 50 mW in, but
that's not going to do much good when displaying the charging indicator uses
more power than that.

------
userbinator
On an electronics forum I lurk, there has been an ongoing discussion about
uBeam ever since it began, and the general consensus is that it doesn't work:

[http://www.eevblog.com/forum/projects/the-ubeam-
faq/](http://www.eevblog.com/forum/projects/the-ubeam-faq/)

(There's more discussion about the recent developments in the last few posts.)

------
samfisher83
Transmitting energy through the air is going to be inherently less efficient
than wires. It looks like you will have to have a direct line of sight.
Wireless energy transmission Bankrupted Tesla and he had a lot money back
then, and he was one of the smartest people ever. 26 Million dollars seems
like a lot of money to put into a project like this when physics would seem to
dictate it isn't going to work.

~~~
mattb314
I'm certainly not long on uBeam (even after this fragile demo), but what
physics dictates that it won't work? Sure, you're certainly going to take an
efficiency loss, but wall outlets already output far, far more power than your
phone uses while charging, so the real questions are how inefficient is it,
how safe is it, and how convenient is it (can a final product survive if it
needs line of sight?). While these are certainly very difficult and perhaps
intractable engineering problems, I'm not aware of a fundamental physical
limit on any of these that would limit an application like phone charging.

~~~
JumpCrisscross
> _what physics dictates that it won 't work_

Wirelessly transmitting energy is fine. It's reliably transmitting a
meaningful amount to tiny, moveable objects near people that's the problem.
You end up with unfeasible combinations of tracking, safety and efficiency
issues. Serious work on remote power transmission doesn't start with consumer
devices.

------
jimrandomh
This is fake. They got some gullible reporters to plug their phones into black
boxes, which are supposedly receiving power. In reality, those boxes contain
sensors to tell them when to pretend to receive power, plus batteries.

If it were real, they would've given the demo to someone with technical
sophistication. They wouldn'tve bothered taking a trip to a phone store, since
all the observers already had their own phones. And, also, the laws of physics
would be slightly different.

But this scam isn't aimed at us. It's aimed at investors, who will never read
this Hacker News thread, or any other thread where smart people are around to
debunk it. Because if they did read that sort of thing, they wouldn't be an
investor.

~~~
tmh79
While I agree with you that this demo is suspect, I think your comment would
be more useful if you backed it up with some of the physics/engineering
principles that support your point of view.

~~~
daveguy
Here are osha safety guidelines for ultrasonic sound:

[https://www.osha.gov/dts/osta/otm/new_noise/appendixc.pdf](https://www.osha.gov/dts/osta/otm/new_noise/appendixc.pdf)

tldr: Maximum 115 dB

Here is a calculator to convert decibels to watts:

[http://www.sengpielaudio.com/calculator-
soundlevel.htm](http://www.sengpielaudio.com/calculator-soundlevel.htm)

tldr: ~0.3 watts per _square meter_

Surface area of a google pixel: 14.3cm x 6.95cm = 0.01 _square meters_

Therefore approximately 0.003 watts over the surface area of a phone at safe
volumes. At 5v that's 0.6 mA. Barely enough to light up LEDs. It looks like
they're working with larger holders, say 20cm x 20cm that's 0.04 sq meters or
2.4 mA at 5v. It takes about 10 mA to trip the "charging" indicator on an
android phone:

[http://liesandstartuppr.blogspot.com/2017/06/what-does-it-
ta...](http://liesandstartuppr.blogspot.com/2017/06/what-does-it-take-to-
switch-phone.html)

This is based on the _raw power of the sound waves_. There will be
inefficiency converting from sound to electricity, so they are probably
dealing with greater than 115 dB sound at the phone. They are probably just
barely tripping the charge sensor for 100 hour charge times. If they are
charging significantly then they are working with very excessive excessive
sound levels (>125 dB).

Given imperfect transducers for 100% conversion of sound to electricity and
the above dimensions they would have to be working with > 122 dB sound at the
phone for 10 mA charge current.

So, it's either a scam or it's not safe. Jamming that much air pressure in a
small space will cause problems and will probably be inefficient.

Sound is not a laser. You can beam form it, it just won't be as tight as a
laser, or even a flashlight. You can't expect clean narrow patterns within a
45 degree cone from the source. There will be high and low intensity
interference patterns. You can even see it in the demo.

------
apozem
> Perry says the sound waves generated by uBeam tech are safe, and the company
> will be "conducting third party tests to assure folks the technology is
> completely safe."

And this is why I don't want uBeam doing the testing- they're certainly not
going to go, "Welp, this technology has some negative health effects. Better
return those venture bucks and shut down the company!"

Any test they do is the scientific equivalent of "Man declares himself not
guilty of fraud."

------
dboreham
This kind of technically unfeasible product scam is surprisingly common. When
I worked for a large Internet company years ago they were looking at an
investment in a start-up that claimed to transmit gigabits through high
voltage long distance power transmission lines. No amount of citing Shannon
and pointing out that said transmission lines are built with fiber lashed to
the ground wire would dissuade them. And these were technically educated
people.

~~~
mschuster91
Huh? Where's the infeasibility there? I mean, PLC is already a reality, just
at 220V instead of 100 kV range but that can be solved by inductively
transmitting signals.

~~~
sathackr
We use coax, fiber, and twisted pairs to transmit signals for a reason -- the
signal stays inside the cable(mostly) and other signals(interference) is kept
out of the cable.

The line voltage is not the limiting factor. To get gigabit speeds your need
to transmit at RF frequencies, and that hundreds of miles-long power cable is
one giant antenna that will interfere with other users of the spectrum.

The power levels used in home powerline network gear are tiny, and the sources
of interference much smaller. And even they have power and interference
restrictions from the FCC to protect other users of the spectrum.

------
foxfired
This reminds me a startup that was at techcrunch disrupt a few years ago.
Cota[1]

The tech seems to be the same whereas it tracks the position of the device
then beams the power. Note however that Cota only sends one WATT of power per
device.

How much does UBeam sends?

[1][https://www.youtube.com/watch?v=_joxrZ6vdYc&t=461s](https://www.youtube.com/watch?v=_joxrZ6vdYc&t=461s)

~~~
jacquesm
Their claims are even more suspect than uBeam's.

------
bastawhiz
Is that an infrared camera mounted to the top of the unit? If so, it would
seem like it's detecting the location with infrared and pointing some energy
at it. What if the device is, say, in a pocket?

All the pics also seem to show the charging sleeves with their backs pointed
at the unit. If they can't work from other directions, that's a huge red flag.

------
wonderous
This looks more promising, "Demo of Short-Range Wireless Power Transfer":

[https://news.ycombinator.com/item?id=13663193](https://news.ycombinator.com/item?id=13663193)

------
TeMPOraL
uBeam really must be the longest running joke in the history of SV. I don't
wear a hat, but I'm going to buy one so I can eat it if it turns out they're
not a scam after all.

------
jondubois
UBeam sounds like it should have been an university research project, not a
startup. Even if the technology does work, is it actually useful and worth its
cost?

~~~
chrisallenlane
Yeah, I had the same impression.

I'll concede that I probably use my phone less than a lot of people, but this
looks like a "solution in search of a problem" to me. I'm still using a Nexus
5 that's several years old, and my battery rarely drops below 80% over the
course of the day. (I only charge my phone when I sleep, and never "top it
off" during the day.)

When I do need to charge it, I plug it in, and can get a full charge in about
an hour, if I remember correctly.

Even if we were to assume that this product is viable technologically (which
is a big "if"), my hunch is that it won't be viable _commercially_ for much
longer as advances in battery and phone technology make it irrelevant.

------
ogezi
I was really skeptical about her company but the pictures in the article and
the article itself seem legit.

I wonder how they'll combat the inverse square law and make their technology
actually feasible.

~~~
trsohmers
Not to be defending/advocating that uBeam's tech is actually any good, but the
inverse square law refers to omnidirectional transmission, while uBeam's
claims are related to directional transmission of power.

~~~
jacquesm
Have you ever seen an audio frequency transducer (say up to 200 KHz) that
delivered an actual beam?

Usually the inverse square law is very much in effect when it comes to audio,
this is because the medium (waves in air) behaves as water does with waves do
in a pond rather than say the light coming out of a laser or any other focused
source of electromagnetic radiation.

Distance from the transmitter will very much be a factor.

~~~
tzs
These people got 53% efficiency at 1 meter, which gives some hope for
ultrasonic power transfer: Roes, M.G.L.; Hendrix, M.A.M.; Duarte, J.L.,
"Contactless energy transfer through air by means of ultrasound," IECON 2011 -
37th Annual Conference on IEEE Industrial Electronics Society , vol., no.,
pp.1238,1243, 7-10 Nov. 2011

Abstract: An alternative approach to the wireless transfer of energy is
proposed, employing acoustic waves in air. Unlike conventional methods,
acoustic energy transfer is able to achieve energy transfer at high
efficiencies over distances that are large in comparison to the dimensions of
the transmitter and the receiver. This paper gives an overview of the
principle and explains the different loss mechanisms that come into play. A
theoretically limit on the achievable efficiency is calculated. It exceeds
that of a comparable inductively coupled system by an order of magnitude.
First preliminary measurements indicate that AET is feasible, although the
measured efficiency is lower than the predicted theoretical limit.

~~~
jacquesm
Grr. I can't access that paper but thank you for digging that up. If Animats'
calculations above are accurate though then uBeam is at a very small fraction
of that 53%.

Is there anything in that paper that could explain the difference?

~~~
m00n
Not sure, if linking to the pdf is frowned upon here: sci-hub.cc and paste the
paper name, voilá.

~~~
jacquesm
Thank you!

------
babyrainbow
So what is new since the last demo?

------
adventurer
Look at the pace at which the battery is charging on the smartphones. That's
not even possible with a wired connection. If they're pumping that much energy
through the air I imagine they would be dead already?

~~~
lolc
In case you're not joking, that's a common "charging" animation in the video.
The animation loops and its speed is unrelated to actual charging speed.

------
JohnJamesRambo
It's amazing what this generation will go through to keep their dopamine
dispenser (their phone) going at all times and available every second to them.

No technology is too inefficient when dopamine is on the line. Kilowatts of
ultrasonic beams aimed at your head to give your phone a trickle charge.

------
monk_e_boy
"Your phone could be at 1% charged all day."

Wow, phones are something like 60% battery at the moment. Imagine cutting that
in half?! Phones could become much more powerful.

