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Power Technology

Mass Market Hopes For Battery-free Cell Phone Technology (reuters.com) 102

Mark Hanrahan, writing for Reuters: Researchers in the United States have unveiled a prototype of a battery-free mobile phone, using technology they hope will eventually come to be integrated into mass-market products. The phone is the work of a group of researchers at the University of Washington in Seattle and works by harvesting tiny amounts of power from radio signals, known as radio frequency or 'RF' waves. "Ambient RF waves are all around us so, as an example, your FM station broadcasts radio waves, your AM stations do that, your TV stations, your cellphone towers. They all are transmitting RF waves," team member Vamsi Talla told Reuters. The phone is a first prototype and its operation is basic - at first glance it looks little more than a circuit board with a few parts attached and the caller must wear headphones and press a button to switch between talking and listening.

Mass Market Hopes For Battery-free Cell Phone Technology

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  • Bitcoins? (Score:5, Insightful)

    by Drethon ( 1445051 ) on Wednesday August 09, 2017 @02:07PM (#54976657)

    Interesting article on bit coins. Now what about this battery free phone?

    • Sigh, mental auto-correct. 28 years of thinking the words bit and coin should always be separate.

    • by Anonymous Coward

      Link to actual article: https://www.reuters.com/article/us-usa-phone-battery-idUSKBN1AP1WG

    • The bot pretending to be an editor by the name of msmash did it again.
      If you scroll down on a reuters.com article and have a shitty modern browser, the site uses shitty javashit to change the URL without actually causing a navigating event for the active viewport.

    • Interesting article on bit coins.

      They've finally decided to make a coin for the American unit of currency commonly called a "bit"?

      • Interesting article on bit coins.

        They've finally decided to make a coin for the American unit of currency commonly called a "bit"?

        Meh, I make a living trading bits for coin.

    • Not a phone it's a crystal walkietalky essentially
  • Nikola Tesla's life obsession was wireless transmission of electrical power. A company that actually makes devices running on wireless power should be called Tesla!

    He didn't give a shit about battery powered cars btw

    • by necro81 ( 917438 ) on Wednesday August 09, 2017 @02:39PM (#54977081) Journal

      [Tesla] didn't give a shit about battery powered cars btw

      I don't know if there's much historical evidence of that one way or another. However, it is worth pointing out that Nikola Tesla invented the AC induction motor [wikipedia.org] - a rather impressive demonstration [wikipedia.org] that AC power distribution [wikipedia.org] could be used for machines. Each Tesla car has an induction motor [tesla.com] in it - something that I think Nikola would be both proud and impressed by.

      • Each Tesla USED to have an induction motor. The model 3 has a three-phase permanent magnet motor instead.

        • by necro81 ( 917438 )

          The model 3 has a three-phase permanent magnet motor instead

          Can you provide substantiation for this claim? I was intrigued to read that, but haven't been able to find anything definitive by casual google searching. The best I saw was forum posts with hearsay, conjecture, and rumor - most of it from a year ago. Now that production cars are out, I expect better information is available.

    • Tesla was a pioneer in the field of electrics which is probably why that name was chosen.

      He had nothing to do with battery powered cars; although such a thing would have been unattainable in his day; had he been around today, he may or may not have had an interest. Who's to say?

      • He had nothing to do with battery powered cars; although such a thing would have been unattainable in his day; had he been around today, he may or may not have had an interest. Who's to say?

        There were reports of Tesla driving around Colorado Springs in a vehicle he built powered by electricity and no wires attached. He claimed to have made it with ideas of radiant energy, which is possible given his experiments in transmitting electrical power through the air, but it's also possible it had a battery (his conception of radiant energy extended to what was effectively a solar cell and a capacitor held at a resonance greater than light, drawing RF, microwave, xrays or gamma rays from the surround

        • which is possible given his experiments in transmitting electrical power through the air,

          no, not it would not have been possible , for fucks sake

      • such a thing would have been unattainable in his day

        Well, not so fast. Wikipedia [wikipedia.org] tells me:

        Acceptance of electric cars was initially hampered by a lack of power infrastructure, but by 1912, many homes were wired for electricity, enabling a surge in the popularity of the cars. At the turn of the century, 40 percent of American automobiles were powered by steam, 38 percent by electricity, and 22 percent by gasoline.

        Sounds like they were pretty attainable to me.

  • by jfdavis668 ( 1414919 ) on Wednesday August 09, 2017 @02:11PM (#54976705)
    They created self winding watches, can't they make self winding cell phone?
  • While people don't like to charge their Smartphones, they don't want to give up their Whatsapp and their big screens either.

    What this might revolutionize, maybe, is the Internet of Shi^WThings. Tiny sensors with attached cell phone modem that phones home the sensor data to a central location. if one can power this from ambient RF noise, that would be awesome and really a billion dollar market.

    • by EvilSS ( 557649 )
      Oh, I see a market for this: nearly eternal listening devices for the governments of the world. Yay technology!
  • Light Reading (Score:5, Informative)

    by Major Blud ( 789630 ) on Wednesday August 09, 2017 @02:17PM (#54976783) Homepage

    Before anyone dismisses this outright, please read up on how a crystal radio works.
    https://en.wikipedia.org/wiki/... [wikipedia.org]
    https://en.wikipedia.org/wiki/... [wikipedia.org]

    • Re:Light Reading (Score:5, Insightful)

      by Joce640k ( 829181 ) on Wednesday August 09, 2017 @02:23PM (#54976867) Homepage

      That's all well and good but the transmitter needs to be very powerful.

      How are the crystal transmitters coming along?

    • by sootman ( 158191 )

      I'm going to dismiss this outright. Since the tech HAS been around for forever (I had a crystal radio set in the early 1980s, similar to the one pictured in wikipedia) don't you think companies would have used it by now if it were viable? What company WOULDN'T want to be able to advertise "OMGLOOK! Our phone doesn't need batteries!"

      From your Wikipedia article: "... crystal sets produce rather weak sound and must be listened to with sensitive earphones, and can only receive stations within a limited range."

    • A crystal AM radio receiver doesn't need to operate multiple microprocessors, graphics engines, audio processors, and last but not least, a transmitter capable of reaching a cell tower miles away.
    • Before anyone doesn't dismiss this outright please read up on how a crystal radio works, and then read up on how a mobile phone works.

  • I'm not particularly worried about RF radiation affecting my health, but how can ubiquitous RF radiation possibly be strong enough to power a smartphone, while being so weak that it can't possibly affect our health?

    Please don't make me have to start walking around in a faraday cage again.

    • I'm not particularly worried about RF radiation affecting my health, but how can ubiquitous RF radiation possibly be strong enough to power a smartphone, while being so weak that it can't possibly affect our health?

      Please don't make me have to start walking around in a faraday cage again.

      I haven't RTA, but the summary says absolutely nothing about smart phones. It is talking about mobile phones. They have much lower power requirements, especially if you make one with almost no screen. Radio Waves are already almost everywhere though, and they don't cause us any harm that we know of.

      The problem is... a decade from now there will probably be fewer radio and over-the-air TV stations. These phones are going to be powered by a dying media.

      • Which is also a problem. The article should be talking about a power source. By tying the power source to a particular use of that power, the conversation gets muddled to say the least.

      • I haven't RTA, but the summary says absolutely nothing about smart phones. It is talking about mobile phones.

        OK, so we're talking about some ultra-low power micro-phone, maybe small enough to fit in your ear like an earbud. That makes more sense.

        I'm still not completely convinced about the total safety of RF waves, though. But then again, I'm a high-functioning OCD case and can only drink from a glass in series of four sips. I count steps. I believe for every drop of rain that falls, a flower grows. I

  • by nimbius ( 983462 ) on Wednesday August 09, 2017 @02:18PM (#54976791) Homepage
    Back in my day we bought the most expensive phones we could! and they were damned slippery too! why, just one errant flick of the wrist you'd destroy an entire paycheck or more of the most advanced, encumbered, and contractually obligated silicon you'd ever set your eyes upon! And the government spied on us all the time and lied to us about it...and we liked it that way!!

    now you damned millenials want to take the battery out? how will my phone swell menacingly over the years due to shoddy manufacturing processes? Back in my day we used to throw parties to celebrate whoevers phone blew up first. Dorris in accounting lost a damn leg from her Samsung but ill tell you one thing...nobody in the office would forget those fireworks! and think of THE CHILDREN! you know, the ones that make these phones and enjoy constant exposure to the byproducts of battery manufacturing. And what about charging?? Back in my day we used to charge all day every day until the battery went bad, then we'd buy more phones! its like you kids dont even understand how fun it is to buy a new phone every year or something.
  • I realize this particular Reuters article may be new; but haven't we seen stories about this exact same research project several times already over the past couple of months?

    • Meh, it's been a few months. Slashdot is required to meet a quota of over-sensationalized quackery that will never successfully develop into a viable product articles or else it loses it's news-aggregation license.
    • Not sure if it was phones last time.

      But yes, this keeps coming up. Anyone that has used a crystal radio set knows how tiny the power is because they know that it is barely enough power to drive even a tiny little in-ear speaker (you know its barely enough power because you can barely hear it.)
      • Crystal radio is so weak because it only uses rf that contains the signal. more modern devices have the entire EM spectrum to feed upon.
  • I wonder... (Score:5, Insightful)

    by darkain ( 749283 ) on Wednesday August 09, 2017 @02:28PM (#54976943) Homepage

    I wonder if this battery-free cell phone from the University of Washington is anything like the battery-free cell phone from the University of Washington last month?
    https://mobile.slashdot.org/st... [slashdot.org]

    • by AmiMoJo ( 196126 )

      Same old bullshit... There just isn't enough RF energy to run a phone. Even staying connected to the cellular network (so it knows when calls are incoming) required more power than can be harvested from RF in the space available in a typical phone.

      I've played with this idea. Ran a small LCD clock off a TV antenna. Only worked next to the window. Unless they crank the wifi up to levels that will fry your organs, this isn't going to work.

  • Correct me if I'm mistaken, but isn't tuning into an RF freq essentially just a form of induction. Meaning, the moment you tune into that frequency, the minute energy captured is also putting a load on the transmitter. So, if everyone in a city tuned into an AM radio station at the same time, there would be a significant draw on the antenna until people tuned off the channel. If so, the energy isn't "free" in a since of being ambient; somebody is paying for that electricity.

    • You are mistaken. The energy must be output whether that energy is used to drive the receiver or not. If you surround one antenna attempting to receive with other antennae, yes, the center one will be blocked, but the same would be true if you used plain metal rods. You are correct that the energy isn't free, and it does come from the transmitter. It's just that modern phones use extra power to properly amplify the signal.
    • by EvilSS ( 557649 )
      Yes, just like solar cells taking in sunlight increase the output of the sun!
      • No, that's not at all what I'm suggesting. Besides, Radio waves aren't photons. However, photons are both a particle and a wave according to quantum theory. Anyways, lets assume that you stretched the comparison to also include light. It would NOT increase the output of the sun, rather, it would reduce available light to other areas. But like I said, doesn't apply here.

        • Okkkk, I was wrong. Radio waves are photons too. Fuck, sorry for wasting your time.

          "All electromagnetic waves, from radio waves with wavelengths L~km to gamma-rays with L~10e-12 m (i.e. 1 picometre, or 1 pm), are made up of bundles of energy called `photons'. ... So EM radiation can show `classical' wave-like properties in some situations, and `classical' particle-like properties in others."

    • by Agripa ( 139780 )

      Correct me if I'm mistaken, but isn't tuning into an RF freq essentially just a form of induction. Meaning, the moment you tune into that frequency, the minute energy captured is also putting a load on the transmitter. So, if everyone in a city tuned into an AM radio station at the same time, there would be a significant draw on the antenna until people tuned off the channel. If so, the energy isn't "free" in a since of being ambient; somebody is paying for that electricity.

      No, it is not the same thing in induction. Induction relies on magnetic coupling which decreases following the cube law. Electromagnetic coupling decreases following the square law.

      Coupling between the receive antenna and transmit antenna in the near field zone could have an effect which is how parasitic antenna elements work but in this case, the energy from the transmitter is already lost in the far field and the transmitter sees no change. If the receiver had a large enough capture area, and capture a

  • Since the article points to something about bitcoins, I can't readily respond to the specifics, but stuff like this has been around a while. You can even find cheap little kits on eBay that power an LED from GSM RF, although those don't work very well in the states. And there are the classic crystal radio kits that have no battery at all.

    The most important thing to develop for something like this is ultra low-power technology, like displays and CPUs that run on less than a microvolt and antennas that can tr

  • NYT Link: https://www.nytimes.com/reuter... [nytimes.com]

    Research web site: http://batteryfreephone.cs.was... [washington.edu]

    Research paper: https://homes.cs.washington.ed... [washington.edu]

  • The interesting aspect is that, given that most people text more than they call, the power requirements for the cell call drop when you use methods like that, making some of the related work on clothing to incorporate cell elements tie in. Basically, Star Trek comm badges become highly viable, using incident work/home power from wi-fi and TV sets, and you can set up common areas to have higher levels of broadcast power (elevator lobbies, conference areas) for actual voice and video calls.

    The future is now.

    • More details on the UW website and in UW Daily and UW News, of course. It's dumbed down from the scientific papers, if you don't have access to those, so most people could read those and follow the links.

    • The only problem with texting is that you need a screen to text (much more power draw), while you don't need a screen for a phone call.
  • at first glance it looks little more than a circuit board with a few parts attached and the caller must wear headphones and press a button to switch between talking and listening

    This was on /. within the last three months.

    Also, judging by the description above it's not a phone, it's a walkie talkie.

  • ... turning a generator will power it indefinitely, so long as I keep turning it. No battery required.

    The problem here is cell phones transmit back to a tower regularly, which requires more power than can be drawn from the air. For that you need either a really big ultracapacitor, or ... a battery. Either that or you can go about your day turning a crank for the generator on your phone.

  • So it's able to harvest enough power from radio signals to power the phone *in real time*? Including the screen?

    I could understand a technology like this being used to *charge* phones, passively, but they would still require a battery. What happens if you momentarily enter a shielded area that radio waves cannot penetrate? Your phone just instantly dies? That would be terrible.

    I *really* hope this is just marketing idiocy, and there is, in fact, a battery incorporated into the design of these devices.

    • by EvilSS ( 557649 )

      So it's able to harvest enough power from radio signals to power the phone *in real time*? Including the screen?

      I could understand a technology like this being used to *charge* phones, passively, but they would still require a battery. What happens if you momentarily enter a shielded area that radio waves cannot penetrate? Your phone just instantly dies? That would be terrible.

      I *really* hope this is just marketing idiocy, and there is, in fact, a battery incorporated into the design of these devices.

      What screen? This isn't a smart phone, it's a very, VERY basic cell phone. No screen included: http://batteryfreephone.cs.washington.edu/ [washington.edu]

    • You wouldn't need a battery. An ultracapacitor would store the gathered energy just fine.

  • by Anonymous Coward

    There is about a 140 decibel gap between the amount of energy you can receive and the amount you need to transmit. My iPhone right now is receiving about -110dBm. To transmit at 1 watt, it needs about +33dBm. That's 140 decibels, or 10^14. Even if you lived in a very RF-rich environment, that only shrinks the gap by say a factor of 1000, you are still 100,000,000,000 times short on power. Not gonna work.

  • This is a rather old idea, but I'm not aware of anyone doing it with modern hardware. You can't actually draw that much power through ambient radio waves, though. In the past, it's never been more than a curiosity because you couldn't build devices that could do anything useful with the amount of power you could get -- but these days, you can build useful circuits that need a whole lot less. This will be interesting to watch.

  • The first thing that popped into my mind when reading the title was the Heechee novels by Frederik Pohl. They were an alien species that required low-level microwave background energy to maintain body warmth, and to power the 'old ones', digitally(?) preserved brain images of the deceased.
    I've often wondered when the level of background radiation was going to become high enough to allow devices to 'capture' this background flux and use it to power low-power devices.
    OK, so it smacks of the 'TESLA' radiated

  • by Anonymous Coward

    If these cell phones become ubiquitous it will play havoc with broadcast radio and TV signals, as well as public safety radios. Millions of phones harvesting radio waves won't leave any signal for legitimate receivers. In fact the very signals these phones need to receive to provide communication will be disrupted. This is a bad idea.

  • There are much more appliances that would benefit a lot from this kind of technology, like remote controls, wall clocks, wristwatches (non/lightly smart), e-readers, all kind of sensors, etc.

  • the caller must wear headphones and press a button to switch between talking and listening.

    Seems more like a battery free walkie talkie. Also, while I can understand how you can recieve with no battery (using old school crystal radio technology) the ability to transmit using no power is quite a surprise.

    • You can't receive or transmit (or do anything at all) with no power.

      Crystal radios get their power from the radio signal itself, and you absolutely can power a transmitter the same way. It just transmits a really, really weak signal. In fact, if you're using a crystal radio, the leads for the earphone are doing exactly that -- only as a side effect rather than by design.

  • Why don't they just plug an outlet strip into itself, then plug the phone charger into that? Infinte power! xD xD xD

    That's what this reminds me of: Troll Physics memes.
  • RF power is no way close to powering your cell phone even 30 min a day of basic operation of talk time. Solar phone covers are already existing and works pretty well.

  • ....an article, I believe from Byte Magazine, about micro tesla coils on a chip that too advantage of all the latent ratio signals that always are around us. About time someone figured out how to actually implement a device that can turn these radio waves into useful energy to power up devices. :)
  • Imagine how long one of these will last with a battery! The problem is not with the capacity of batteries - the problem is with how many things a modern phone is asked to be.

  • How many "battery breakthroughs" announced in Slashdot over the years have ever made it to the masses? One in fifty? One in a hundred? None/
  • I built a crystal radio when I was 6. It also required the user to wear a mono earpiece. https://en.wikipedia.org/wiki/... [wikipedia.org] I guess my 6 year old self was smarter than the researchers they have at the University of Washington.
  • by SuperDre ( 982372 )

    This really isn't a phone, because what they forget to mention is that this is actually nothing more than the 'receiver' (as in microphone/headphone), it has a basestation that does the actual digitizing and has the rest of the phoneparts (it's not even to be compared to a DECT handset and it's basestation), which ofcourse drinks it's juice from the wallplug.

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