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Researchers Have Developed A Battery-Free Mobile Phone (hothardware.com)

Posted by EditorDavid on from the fight-the-power dept.

An anonymous reader quotes HotHardware: Researchers from the University of Washington are looking to make batteries a thing of the past when it comes to mobile phones. The team has developed a phone that uses "almost zero power" according to associate professor Shyam Gollakota, who co-authored a paper which detailed the breakthrough... The researchers designed the phone to harvest microwatts of power from RF signals transmitted from a base station that is 31 feet away. Additional power is harnessed via ambient light through the use of miniature photodiodes that are about the size of a grain of rice. While in use, the phone consumes about 3.5 microwatts of power and is capable of communicating with a custom base station that is up to 50 feet away to send and receive calls... The phone ditches the traditional analog-to-digital converter, which turns your voice into data, in favor of a system that uses the vibrations from a microphone or speaker to perform the same task. An antenna then converts that motion into radio signals in such a way that very little power is consumed.
There's two drawbacks. First, modern smartphones "need a lot more than a 3.5-microwatt power budget for blazing fast processor, copious amounts of RAM and internal storage, and power-hungry displays." And more importantly, "you have to press a button to switch between transmissions and listening modes with the phone."

47 of 83 comments (clear)

  1. Congratulations by Anonymous Coward · · Score: 5, Insightful

    You re-invented a walkie-talkie.

    1. Re:Congratulations by thegarbz · · Score: 3, Interesting

      Indeed. Calling this a mobile phone is utterly stupid clickbait. There's nothing "phone" about it.

    2. Re:Congratulations by blindseer · · Score: 3, Informative

      Or a cordless phone.

      The range is 30 or 50 feet. That's barely enough to get across my house, and I don't have a large house. The 1/R^2 law has to put some realistic limits on range.

      This is just another "wireless electricity" article that gets clicks but no real application. Unless page views was the intended application.

      --
      I am armed because I am free. I am free because I am armed.
    3. Re:Congratulations by DontBeAMoran · · Score: 2

      Well it is phony.

      --
      #DeleteFacebook
    4. Re:Congratulations by AmiMoJo · · Score: 1

      It's also bollocks. It must have a battery, there is no way 3.5uW could power a speaker for you to hear the other person. It must harvest energy over time into a battery, and then consume it when you make a call.

      Energy harvesting does have its uses, like wireless sensors for example, but this isn't one of them.

      --
      const int one = 65536; (Silvermoon, Texture.cs)
      SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
    5. Re:Congratulations by Anonymous Coward · · Score: 2, Insightful

      I guess you've never heard of crystal radios. If you RTFA you'll notice that the "speaker" is actually a pair of headphones and, in all likelihood, only one of them will be getting signal.

    6. Re:Congratulations by kqs · · Score: 4, Insightful

      With base stations that are "up to 50 feet away", I have more problems with the word "mobile", actually.

    7. Re:Congratulations by bug1 · · Score: 1

      "A crystal radio receiver, also called a crystal set or cat's whisker receiver, is a very simple radio receiver, popular in the early days of radio. It needs no other power source but that received solely from the power of radio waves received by a wire antenna."

      https://en.wikipedia.org/wiki/...

    8. Re:Congratulations by tlhIngan · · Score: 1

      It's also bollocks. It must have a battery, there is no way 3.5uW could power a speaker for you to hear the other person. It must harvest energy over time into a battery, and then consume it when you make a call.

      You can use capacitors instead as your energy-storage mechanism, or inefficiently, inductors. Batteries are just one form of energy storage, but capacitors may be a better fit as they can provide the spike of power transmitters generally need. Plus there aren't charge cycle issues with capacitors - which may be essential if it charges and discharges that quickly.

    9. Re:Congratulations by omnichad · · Score: 1

      And if we get rid of all encryption, multiplexing, and everything useful, it might sort of work. Otherwise, you need more power.

    10. Re:Congratulations by stooo · · Score: 2

      Yep. Nothing new.

      it's basically this :
      https://en.wikipedia.org/wiki/...
      combined with this :
      https://en.wikipedia.org/wiki/...

      it's basically worthless.

      --
      aaaaaaa
  2. So... by Anonymous Coward · · Score: 1

    They've actually just advanced and optimised a kids' radio set?

    1. Re:So... by Anonymous Coward · · Score: 1

      Im not sure a 10 meter range is an advancement

  3. Not a phone.... by Anonymous Coward · · Score: 5, Insightful

    This is not a phone. Its an ambient RF powered walkie-talkie, the likes of which have existed for 15+ years at least.

    This isnt even a good version, needing its own POWERED RF transmitter with a max range of 10 metres. If you have power 10M away then why not use it to charge a battery and have a device that is actually useful?

  4. Two problems? by 93+Escort+Wagon · · Score: 3, Insightful

    There are more than two major problems. The requirement of a nearby base station (or other RF source) is a significant drawback.

    However the research is interesting - and people need to remember this is intended as rather fundamental research, not something that's ready for commercialization. And the "walkie talkie" comments are really missing the mark, since the person you're talking doesn't have to be local.

    --
    #DeleteChrome
    1. Re:Two problems? by DontBeAMoran · · Score: 1

      Make that a CABBAGE PATCH TICKLE ME ELMO NEW CHERRY COKE and I'll buy one.

                     

      --
      #DeleteFacebook
    2. Re:Two problems? by 93+Escort+Wagon · · Score: 1

      Good point. A cordless home phone would be a more apt comparison than a mobile phone.

      --
      #DeleteChrome
    3. Re:Two problems? by 93+Escort+Wagon · · Score: 1

      So, by that same logic, a cell phone call is a conversation between you and a cell tower. Most people aren't going to see it that way - but you're welcome to employ more tortured verbal gymnastics, if you wish.

      --
      #DeleteChrome
    4. Re:Two problems? by EETech1 · · Score: 1

      Thought 5g had to have a base station every 75 feet or so...
      Sounds perfect.

    5. Re: Two problems? by Ash-Fox · · Score: 1

      They also forgot about the little problem of it being illegal. Taking power from random transmissions to power a device is not any more legal than cutting into you neighbors power lines to power your fridge (in most jurisdictions at least, I know for sure about Germany).

      Why aren't crystal radios illegal in Germany then?

      --
      Change is certain; progress is not obligatory.
    6. Re: Two problems? by AC-x · · Score: 1

      That's not how broadcasting works, that's not how any of this works!

    7. Re:Two problems? by green1 · · Score: 1

      If you insist on trying to torture your verbal gymnastics, you'd try to tell us that a cell phone, a cordless phone, and a wired phone are all the same because they can all talk to people on the other side of the planet. But people know the difference is in how far they can walk with it before they lose a signal (for wired that's the length of the cord, for cordless that's somewhere on their front lawn, and for cellular it's anywhere where there's a tower within a few kilometres)

      Based on that definition, this device is somewhere between the wired and cordless phones. So calling this a cell phone is pretty stupid.

    8. Re: Two problems? by green1 · · Score: 1

      citation needed.

      In most parts of the world it is perfectly legal to receive any signal that hits your antenna. (Often there are caveats for particular types of signals, but usually that's just about decoding and reading/listening to the data contained in the signal, not in whether you took some of the energy out of the air)

  5. Welcome to 1945 by darkain · · Score: 2

    Welcome to 1945. Glad to know you're "invented" something amazing! https://en.wikipedia.org/wiki/...

    1. Re:Welcome to 1945 by green1 · · Score: 1

      Hence the reference to "the thing" because it was in fact a transmitter...

      It's really "the thing" and a crystal radio in the same box. Hardly revolutionary.

  6. It's not a phone .... by PPH · · Score: 1

    ... unless you can play games on it.

    Rovio will be coming out with one soon just for this device: Anemic Birds.

    --
    Have gnu, will travel.
  7. Cordless phones by alvinrod · · Score: 4, Informative

    This sounds more like a cordless phone than a mobile, unless you never move more than a few dozen feet.

    A cordless phone that didn't need to be put on a charger would be a pretty good convenience. Of course who the hell has a landline anymore these days.

  8. April fool's? Just stupid? by ooloorie · · Score: 2

    The phone ditches the traditional analog-to-digital converter, which turns your voice into data, in favor of a system that uses the vibrations from a microphone or speaker to perform the same task. An antenna then converts that motion into radio signals in such a way that very little power is consumed. However, reminiscent of a walkie-talkie, you have to press a button to switch between transmissions and listening modes with the phone.

    So, in different words, they have built a very-low-powered analog transmitter and receiver... something people have been doing for about half a century.

    Congratulations on the completion of a high school science project! I'm afraid it's still just an also-ran, however.

  9. Re:Two types of gays by DontBeAMoran · · Score: 1

    If God hates fag why did he create them?

    --
    #DeleteFacebook
  10. Re:Why should I care? by DontBeAMoran · · Score: 1

    Here you go (probably NSFW unless you're in Japan).

    --
    #DeleteFacebook
  11. Re:Soon on Apple News by DontBeAMoran · · Score: 1

    Only Apple can invent a battery-free iPhone.

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    #DeleteFacebook
  12. Comms Badge? by Anonymous Coward · · Score: 1

    If you could make it small enough, it might work as a standalone Communications Badge.

    1. Re:Comms Badge? by Gavagai80 · · Score: 2

      It would be so much easier to just put a 15 year watch battery in it for consistent power.

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      This space intentionally left blank
  13. 2 cans and a string.... by tekrat · · Score: 1

    This is not a phone. It's a solar powered walkie talkie. You're limited in range, it's not cellular, it's not a phone. I can invent a mobile phone that uses no power using two soup cans and a string to communicate with a base station (Amazon Echo).

    --
    If telephones are outlawed, then only outlaws will have telephones.
    1. Re:2 cans and a string.... by scdeimos · · Score: 1

      I agree, there's nothing cell-phoney about this thing. To be fair TFA just took UW's bait hook, line and sinker: a photo of the device clearly shows the silk screened words, "UW Battery-free Cellphone."

    2. Re:2 cans and a string.... by omnichad · · Score: 1

      there's nothing cell-phoney about this thing

      There's something cell-phony about this thing.

  14. It's a walkie-talkie with a base station by Proudrooster · · Score: 1

    Why not just get a solar powered walkie talkie and forget it?
    This is not a full-duplex nor is it a cell phone communicating in the 2.4Ghz band to a cell tower 1-10 miles away.

    News flash, you can build something far superior to this today, get a Nokia brick phone and a solar panel case. Boom! Done! No base station required, not PTT (Push to Talk) button required. It will have a battery but never need traditional charging.

    How is this high-tech geek news?

    Anyone?

    1. Re:It's a walkie-talkie with a base station by viperidaenz · · Score: 1

      Cellphones don't communicate with cell towers in the 2.4GHz band either

      It's usually 750MHz, 850MHz, 900MHz, 1.8GHz 1.9GHz or 2.1GHz

  15. Re:Soon on Apple News by viperidaenz · · Score: 1

    Cisco could too...
    https://en.wikipedia.org/wiki/...

  16. It is not a phone. by 140Mandak262Jamuna · · Score: 1
    It is not a phone. It does not even have MMS, don't even think about whats app. Neither forward facing camera, nor rear facing. Absolutely no selfie mode. No wifi and no bluetooth. No calender, no apps, no games, not even snake.

    At best it can do some voice communication using electric signals. How anyone would confuse this with a phone, I can't imagine.

    --
    sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
  17. Not a phone by jandjmh · · Score: 1

    The described device is equivalent to a blue tooth headset.

    1. Re:Not a phone by green1 · · Score: 1

      Bluetooth actually has over 3 times the range of this device, and can support transmitting and receiving at the same time, so I don't think this is a good analogy either.

  18. Star Trek Combadge by Anonymous Coward · · Score: 1

    This could be used to make a combadge like device.

  19. Awesome surveillance device. by Anonymous Coward · · Score: 1

    says it all

  20. No Sources by Verdatum · · Score: 1

    The closest thing to a source in this clickbait article is a crummy YouTube-like video. The other links are just links to tags on that same woefully named "hothardware" site. EditorDavid, don't accept submissions like this.

  21. Re:vocal vibrations by green1 · · Score: 1

    Not at all a fair comparison. With a long enough string you could easily get a longer range than they did on this device...

  22. Re:mobile phone != smartphone by green1 · · Score: 1

    Apparently you missed that this "invention" also != mobile phone.

    Unless by "mobile phone" you mean a device that can't talk and listen at the same time, and has a usable range from the handset to the "tower" shorter than the distance from my bedroom to my kitchen.