An Inventor Wants One Less Wire to Worry About
nytimes.com
nytimes.com
I was feeling really bad about myself, but then I realized: without such skepticism the surprise and delight of proving others wrong (not to mention being proved wrong) would be lessened, and so my skepticism does serve a useful purpose, and I could go on living with myself again. This is one skeptic who's hoping that he's wrong and that the inventor is right!
Sometimes it takes an outsider to challenge assumptions and achieve a breakthrough, but I don't think thats going to happen in this particular case.
[1] http://www.ted.com/talks/larry_smith_why_you_will_fail_to_ha...
Train everyone in a discipline that everything must be green. This idea of turning perhaps 99 watts into heat and 1 watt into battery charge is terribly non-green. "Everything must be green" is the cognitive filter which had to be overcome.
In cold climates, especially if you have electric heating, turning electricity mostly into heat is not as much of a loss as you'd think, anyway. In areas of Canada with cheap hydro and electric baseboard heating, its probably a great idea.
/song
The world needs people like you and me
who've been knocked around by fate.
'Cuz when people see us, they don't want to be us,
And that makes them feel great!
We provide a vital service to society
You and me!
Wireless power is something that has been researched for years I believe, the fact that to this day there is not a feasible solution (that I know of) means that it's a really hard problem, I guess.
The amount of power needed would really depend on the device and the application, I guess.
How many mW are we talking about, in the best case scenario ?
http://electronics.stackexchange.com/questions/4664/stealing...
One of the answers has the following math: For a large radio tower (100kW), you'd get roughly 80 W per square meter of receiving antenna area at 100m distance.
Since the typical distance to a nearby radio tower is probably more like 5 miles, we can reduce that to ~12mW for a 1m^2 antenna. For the size of a phone, we're talking more like 0.10mW, which is about 10,000 times less than a typical phone needs (assuming it was charging 24/7 with 100% efficiency).
Although, the answer gives the formula as 100kW/(4 * pi * r^2), which seems to give 0.80 W/m^2 instead of 80 W/m^2, so perhaps divide my other answers by 100 (and make that 1 million times lower than the power necessary to power a phone)
EDIT: I previously stated the formula gave the wrong units which was a mistake.
The biggest problem is going to be PR. So wifi milliwatts of microwave power tens of feet away make hypochondriacs and conspiracy theorists think the government is controlling their thoughts using radio waves... I'm guessing "tens of watts in a ISM diathermy band" is going to substantially encourage them.
For a non-directional beam, it would be P/(4.pi.r^2).
Perhaps the steering could be done cooperatively with the device(s) being charged. I.e., devices announce their location to the charger, and the charger steers the beam towards them.
Maybe that would bring the power required down to a reasonable range.
From Wikipedia:
"Although the long term effects due to ultrasound exposure at diagnostic intensity are still unknown,[24] currently most doctors feel that the benefits to patients outweigh the risks.[25] The ALARA (As Low As Reasonably Achievable) principle has been advocated for an ultrasound examination — that is, keeping the scanning time and power settings as low as possible but consistent with diagnostic imaging — and that by that principle non-medical uses, which by definition are not necessary, are actively discouraged."
Another interesting one is phase noise and distortion and crossover distortion (if you use a simple class-B amp) means you can send a sine wave into a high power amp, but the amplified noise level at audible range might be icky. As a personal anecdote I've noticed this with commercial ultrasonic cleaners. Sure... noise level might be 30 dB down at audible range, but pump a 100 watts at 40 KHz into it and I'm listening to 0.1 watts of noise at audible freqs which is quite loud indeed. Theoretically ultrasonic cleaners should be inaudible, but high powered ones are not. Much as intermod distortion is hilarious with high power RF, noisy/corroded/semi-faulty ultrasound could be loud as heck acoustically thru no fault of the generator, amp, or transducer.
Building a working prototype that can beam ~1W (or even 100mW) a few feet would be very interesting and would do a lot to lessen my skepticism.
The design in that video involves transmitting ultrasound from a central charging station to an ultrasound receiver and that receiver is then plugged into a cell phone using a normal cable. The claim in that video is that it takes 3.3 hours to charge the receiver but she doesn't actually mention the watts or joules involved. Given that most claims of technology that can charge a device from across the room have turned out to be bullshit, I'm going to lump this claim of into the same bucket until there is more evidence to show otherwise.
I'd be hard pressed to imagine this working over distances larger than the 3 feet demonstrated, which suggests constraints on the use case, like charging your laptop while its on a desk, for which there would seem to be easier methods of wireless charging (inductive coupling, conductive pads, etc).
Very interesting in concept, I'd like to see numbers before I believe anything.
Unless this transmits as well as a cable, I'm not interested.
Also, there could be a risk of ear damage if a non-linear material came into the sound field, and producing distortion artifacts in the audible frequency range - given that about 1W/m^2 can be enough to cause damage.
My dentist's ultrasonic dental plaque removing tool produces audible squeals reminiscent of analog tuning of an AM radio. That's one possible example of probable nonlinearities (in my gums an teeth) producing detectible audible power from ultrasonic energy transmission. No reference -- it's just what I hear every time I have my teeth cleaned.
Granted an ultrasonic water stream (dental application) has different physical characteristics than an ultrasonic air pressure wave (ultrasound).
Ultrasound is mechanically filtered, so it can't propagate into your cochlea and damage the hair cells. This is in contrast to something like photons, where UV or infrared light can absolutely damage your photoreceptors in your eye.
50KHz is just two octaves above our normal range of hearing. She's claiming "charge laptop in 3.5 hours" levels of power transferred to a transducer "the size of a flash drive" a useful distance away.
Now apply the inverse square law to estimate the necessary output power or assume a focused beam.
Now imagine that flash drive is your ear, your eyeballs, or a pregnant lady.
Did she ultimately get investment because she was a woman, in spite of the hardware business?
According to a friend's college thesis, there are lots of concrete reasons VCs don't invest in women.[0] In summary, VCs don't take a girl very seriously. The thesis makes the case though that there's real opportunity for women founders, not the least because they're so undervalued for reasons under than business fundamentals.
So maybe Meredith got investment precisely because she was a woman. The collection of investors is curious. According to CrunchBase, Marissa Mayer invested in 8 companies over the last 2 years (+Square in 2009), 7 of which have women founders or co-founders. Lady Gaga's manager, who I thought was not a professional investor, in fact makes a lot of investments. According to CrunchBase, 4 of 16 of his investments have women founders or co-founders. By comparison, VentureSource shows about 1 in 14 startups with funding have women founders or co-founders in 2010—more details in Alisha's paper.
Still, it would be wrong to accuse of sexism the "hundreds" of the investors who declined her project. She's an astrobiologist who wants to run a mass-manufacturing business. I'm not a venture capitalist, but I can see aversion to hardware manufacturing risk generally being the biggest factor here.
[0] http://alisharamos.com/women-vc-funding/AlishaRamos_Thesis.p...
As physics as generally understood means this is 99% likely to be nonsense, another reasonable application of Ockham's Razor would be that the VCs passed because it's snake-oil.
A+ on not putting "Woman" in the headline for the article, though!
wifman = female human
werman = male human
man = human
Even if it's got some sort of feedback that allows it to be a highly concentrated beam between devices it still seems to me it'll be very lossy.
Loss in the air. Loss in transforming the energy twice more than normal.
I like this use of piezoelectric devices to turn heat into sound into energy:
And you know what, I have an invention that means your laptop will continue to work in almost any position - you won't have to keep a clear view between charger and laptop. You can turn around, lie down, have a colleague stand over your shoulder. There are some limits, sure, but it gives you a fair bit of freedom to move, and it allows a ton of power to be more effectively transmitted along its full length (with negligible loss), and you can use it anywhere you can find consumer power. It's called a 'wire'.
I do a lot of cross-protocol work, and I've seen that a lot from "domain experts".
Me: Why can't we just do X?
Them: It would violate the standards, and industry practice!
Me: how could anyone tell?
Them: Uh... they couldn't. Good idea. Let's do it.
There's a danger in letting your brain ossify. Cray used to hire young people for precisely this reason:
http://www.cgl.ucsf.edu/home/tef/cray/tribute.html
> Once asked why he often hires new graduates to help him with early R&D work, he replied, "Because they don't know that what I'm asking them to do is impossible, so they try."
Keeping abreast of emerging tech is hard for specialists whom are focused deep within their silos. It's always good for teams to include broad-minded generalists that continually survey the landscape, connect the dots, and keep the team's reservoir stocked with fresh developments from the outside world. At some point a specialist may recall something from the reservoir that turns out to be the missing piece that enables your team to break through the silos and jump the curve.
I'm not trying to troll with pedantry here, I'm genuinely interested in the reasoning that surely went on at the NYT.
(BTW, since you were one of us who was reading carefully, how did you like this phrase: "it was almost like a stoner’s aha:" ?)
The stoner quote was immortal, but I'll raise you:
Nothing in her training prepared her for this kind of research. She was an astrobiologist, after all.
Hum... in this particular case, the problem is to make a prototype. If you have a working prototype for safe wireless energy transmission, no doubts that you'll find customers willing to buy it.
What if we made a house sized one and buried it under the house? Could that provide wireless electricity to the whole house?
[1] http://hackaday.com/2013/06/19/adding-wireless-charging-to-a...
[1] http://mobile.nytimes.com/2013/08/18/technology/an-inventor-...