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Power Portables Science Hardware

A Tablecloth to Charge Your Laptop 119

Posted by CowboyNeal from the unplugged-and-loving-it dept.
moscowde writes "Research scientists at the University of Tokyo have come up with a unique sheet-like material that can transmit electrical energy over a large area to nearby devices without the need for direct contact, so it can be made into a tablecloth or wallpaper and your appliance can be anywhere on a surface to get charged. The system uses organic molecules as transistors, microelectromechanical switches, and miniature copper coils to transmit energy using electromagnetic induction."
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A Tablecloth to Charge Your Laptop More

A Tablecloth to Charge Your Laptop

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  • Replace for power cables and plugs? (Score:4, Interesting)

    by astonishedelf ( 845821 ) on Friday May 04, 2007 @07:42AM (#18986105)
    If this could help get rid of the mess of power plugs and cables under my desk, this would be utterly fantastic. Wonder what happens if a liquid is spilled on the surface though...
    • you would think so, but initially it will probably be like some earlier bluetooth stuff (especially keyboards and mice)...

      Namely, it's nice, but each device works with the adaptor that came with it and nothing else, so you still need one wire per device...

    • Nothing (Score:4, Interesting)

      by CarpetShark ( 865376 ) on Friday May 04, 2007 @08:02AM (#18986267)
      It sounds like magnetic induction -- same thing they use to charge electric toothbrushes without exposing any wiring to water and toothpaste. It should work just fine with water.

      My questions on this would be more focused on how practical it'll actually be, unless it's standardised so that different devices can charge off it, and on how wasteful it is, if it's throwing out energy even when nothing needs it.

      • Re: (Score:2, Insightful)

        by Mythrix ( 779875 )
        Eouldn't a magnetic field affect the hard drives and monitors?

        And standardisation would definitely be good, so we don't end up having to buy a Sony tablecloth for cellphones, Dell tablecloth for laptops and Philips tablecloth for the toaster.

        • There are a lot of standards - too bad SONY chose not to use them. Do you really think they would let you use your no-name charger pad instead of buying their special SONY-pad for three times the money?

          s/SONY/Apple|Nintendo/

      • How efficient is it? In these days of global warming the last thing we should be thinking is replacing all those chargers which are left plugged in 24/7 with something that's even less efficient...

        • Can we please stop trotting out this global warming shibboleth? Global warming, cooling, neutraling, whatevering, doesn't enter into it. If it isn't efficient, you're wasting money and in these days of global warming hype keeping backlash against energy expense increases suppresed, I haven't got a whole lot to go around.

          I don't care if that tablecloth has checkered patterns and makes my Italian cooking better, if it costs me more than it is worth, I ain't buying it.
      • Imagine now that all that magnetic field affecting all you cards in your wallet, it would have to be small so not to interfere , you would probably have problem with tv's and or crt monitor (very bad with magnetic fields)

    • Liquid Spills (Score:3, Informative)

      by moscowde ( 1096675 )
      In original research paper published in "Nature Materials" there is a picture of a fish tank with fish inside. The light inside the tank is powered using this transmitting material. Power cables, sockets, and plugs are not required, and all of the metallic parts are coated with insulating materials. So it is safe.

  • Tablecloths and wallpapers? (Score:5, Insightful)

    by Anonymous Coward on Friday May 04, 2007 @07:44AM (#18986121)
    I'm sure there's nothing harful in wrapping ourselves in yet more electromagnetic fields, not even shielded ones in this case.

    I mean, what could possibly go wrong? After all little Jimmy's third arm is quite handy.

    • Re: (Score:3, Interesting)

      by Goaway ( 82658 )
      Nothing has gone wrong so far except that the psychosomatics have a new thing to complain about, so I don't see why a little more would be a problem.

    • Re: (Score:2, Funny)

      by maxume ( 22995 )
      Yeah, it's a good thing that there isn't some huge electromagnetic source that just appears in the sky all the time, that would be scary.
    • third arm...

      or the big news right now, Colony Collapse Disorder [wikipedia.org].

      • Re: (Score:2)

        by geekoid ( 135745 )
        SIgh...You know that they found out what's doing that, right?

        And it is happening in a lot of places no where near enough to man made magnetic fields right?

        No, lets look at something that couldn't possible do it.
    • Get with the program! Plugging in the power adaptor is HARD WORK. We should not have to do such manual labor when technology can save us from drudgery.

      • Re: (Score:1)

        by Jeta ( 1097915 )
        Especially when it's handwashable technology. I can see it now... Electric napkins for PDAs and cell phones! :P This is actually quite interesting. I hope they can get it off the ground and into production for the masses, unlike all that other cool tech that you hear about and never see in action. Although, there's just something about the personality of the Power Cord that I've lived with for so long, I don't think I could get used to never having to plug something in ever again.
    • The FCC is definitely not going to like the sound of this
  • Nothing I want more than putting my metal cup down on a frayed kink on the basement table with my bare feet. Wearing a pacemaker?

    • Re: (Score:3, Funny)

      by Charcharodon ( 611187 )
      Grampa if you don't get me a pony and take me to the zoo, I'm going to recharge my ipod! Then you'll be sorry!

    • Nothing I want more than putting my metal cup down on a frayed kink on the basement table with my bare feet.


      You would be more likely to put your metal cup down on the table and then burn your hand trying to pick it up. Induction is a widely used method of heating pots and pans for cooking. Induce a current in a metal pot and it will heat up due to the resistance of the metal.

    • Re: (Score:2, Funny)

      by account_deleted ( 4530225 )
      Comment removed based on user account deletion
  • Sweet, no cords for my laptop! but i still need to plug in my dinner table. personaly if i wasnt at a work station id be in a chair with my notebook on my lap
  • It sounds cool and convenient, and unlike the RF couplers that have cropped up lately they are up-front about efficiency: >80%, which they achieve by activating only the area where the power "receiver" sits--not blanketing a large area. However, the energy-conservation targets set by EPA, California, etc. are even higher. There needs to be further improvements before this can be a marketable solution. I hope they happen soon!
    • The 80% efficiency could be compensated for if the mat has 1) low standby consumption and 2) an efficient power supply itself. Remember that you're potentially replacing several inefficient wall warts which are frequently left plugged in 24x7 even when the ipod/cellphone/pda/... is off in your pocket.

  • Waiter! (Score:5, Funny)

    by Timesprout ( 579035 ) on Friday May 04, 2007 @08:01AM (#18986257)
    My soup has electrocuted a fly!

  • Tesla did it 100 years ago (Score:3, Interesting)

    by 140Mandak262Jamuna ( 970587 ) on Friday May 04, 2007 @08:05AM (#18986291) Journal
    One of the intriguing Nichlai (sp?) Tesla did in his lab was to place an inductive ring just below the cieling like crown molding. Then he had electric motors powered by inductive coupling. Instead of "plugging" in the device to the wall socket, all he has to do was to raise a ring the ceiling. To "unplug", lower the ring by a few inches. Will try to find some references and post it soon.
    • Nicoli Tesla (finally got the spelling right) experimented with wireless transmission of power. Jagdish Chandra Bose was working on wireless transmission of data. Tesla was into transmission of power. The key to transmit data was what Bose called "coherer" which is essentially a coil with a very precise resonating frequency. The second issue was an amplifier that would not distort the signal. Marconi saw Bose's coherer design and built his radio based on that. Bose remained in India in 1890s did not see the

      • Re: (Score:3, Informative)

        by Cyberax ( 705495 )
        "Coherer" is NOT a coil. See http://en.wikipedia.org/wiki/Coherer [wikipedia.org] for details.

        Wardenclyffe tower would have never worked, intensity of electromagnetic field obeys inverse square law, so you'll need a LARGE antennae to catch more than a few milliwatts at a distance more than a few hundred meters.

        • Re: (Score:2)

          by fatboy ( 6851 )
          Radiator/antenna efficiently can be affected by it's length. The length of the radiator/antenna required is determined by the frequency of the electromagnetic wave. All of this has little to do with inverse square law.

          Go higher in frequency, a smaller antenna is required, yet RF density at a distance will not change (much).

          • Re: (Score:2)

            by Cyberax ( 705495 )
            It has EVERYTHING to do with inverse square law. Antenna can't catch more energy than that of passing through the space occupied by it.

            Additionally, energy density of electromagnetic WAVES is proportional to the cube of its frequency, so it's much easier to transmit a lot of power at high frequences. For example, ELF transmitters use hundreds of kilowatts of electric power but output just a few _watts_ in ELF radio frequences. But the ease of transmission has nothing to do with inverse square law.

            And you'll

            • Re: (Score:2)

              by fatboy ( 6851 )
              Thanks for making my point. Inverse square law has little to do with the size of the antenna required. The frequency has more to do with size of the antenna than the surface area used to receive the signal. Placing parasitic elements around the antenna do more in helping increase it's efficiency than lengthing it.

              BTW, the reason ELF antennas have such small ERP is because of the relationship of the distance of the radiator above the ground compared to the wavelength, as well as, the relatively short length

    • Re: (Score:2)

      by WoLpH ( 699064 )
      I'm just wondering, why don't we hear anything about the fuel cells anymore? It was in the news daily a couple of years ago and right now I haven't seen any news about it in months.

      Either way, great to see that they've been able to keep the efficiency heigh, 80% is really not bad for an induction system.
      From TFA

      The sheet is 21×21 cm, 1 mm thick, and weighs 50 g. It contains a grid of 64 position-sensing units and 64 power-transmission units. The sheet is capable of providing 40.5 watts of power wit

    • Re:Tesla did it 100 years ago (Score:5, Interesting)

      by Lumpy ( 12016 ) on Friday May 04, 2007 @08:40AM (#18986645) Homepage
      yup and I did it 15 years ago in college. I made a charging mat that was basically a thick tablecloth that did the EXACT SAME THING. I based my thesis and final project on Tesla's work and even gave details. One thing I did was to increase the Frequency to 400hz that allowed me to have a weaker field to transmit the same power to eliminate the magnetize everything in a 4 foot radius effect.

      It worked great and if you did your calculations right the tailored recivers for each device were incredibly easy to build and interface to the device. I modified a Motorola Brock phone to charge from a coil I placed in it's battery compartment.

      The only reason thses things do not take off is that device makers make HUGE $$$ off of "accessories" like chargers. Dell rapes you blind on their charger prices, Apple and Nokia do the same. and they all go out of their way to make sure it uses a wierd voltage and wierd connector to make sure you cant easily use something else.
      • The only reason eh? I'd wager another big reason is because of people who make posts like "what happens if I put my elbows on the table" or "what if I spill water on it?" i.e. The public's fear of electricity.

        • Re: (Score:2)

          by Lumpy ( 12016 )
          "what happens if I put my elbows on the table" or "what if I spill water on it?"

          I was a big smart-arse back in college and I was asked that question by someone else in the class.

          my response was "Why you Die a horrible electric death of course. It also fuctions as a Gene pool cleaning device."

          In reality it's 100% safe unless you put it under your pillow and sleep with your head on it. I demoed it with a glass of water sitting on it as well as a set of keys. The keys did not even warm up but do act as a co
          • Is the head thing is a result of the constant exposure to the radiation, or something more nefarious like you hooked it up to a mind control device?

            Any idea what the efficiency of something like this is compared to say, a wire?

            How about "standby mode" as has become so popular in all sorts of appliances these days, can the tablecloth sense that no one is drawing its current and dial it back a notch until someone is?
      • This is a complete tangent, but I can't help myself. Would that paper happen to be available online? I heard about Tesla doing this and I never could grasp the concept of wireless transmission of electricity (then again, I'm a computer scientist, and my understanding of electricity ends with Ohm's Law... which I've actually forgotten a third of at the moment), but I'm quite curious and I hate wondering about the same thing for more than a decade without at least trying to figure it out. The only way I can

      • Re: (Score:1)

        by mu22le ( 766735 )

        yup and I did it 15 years ago in college

        care to post a link to your work? I'd be courious to take a look at it...

        Or do you have paper copies only?
    • Inductive coupling is only the first step of the idea, because of a couple of important problems:
      - you can't select who receives the power: your laptop will recharge, but your engagement ring will burn your finger off.
      - most of the emitted power will dissipate into thin air.

      Of course, this product improves on the idea by powering only the area closest to the device to recharge.

      Dammit, I had this nice article explaining some promising research in the field, but I'm unable to find it again...
      T
  • Some of these types of EM sources really bother me. At certain frequencies I can actually feel the EM field as a slight tingling in my skin. My Wacom tablet does it but my hand has to be pretty close to it to feel anything (which is really annoying because I otherwise love that tablet).

    I wonder what this would feel like? I imagine it would have a pretty high level of output, I wonder what frequency it runs at and if it will bother some people. It could make being anywhere near one of these charging tabl

    • Re: (Score:2, Funny)

      by Anonymous Coward
      At certain frequencies I can actually feel the EM field as a slight tingling in my skin. My Wacom tablet does it but my hand has to be pretty close to it to feel anything (which is really annoying because I otherwise love that tablet).

      If I were you I'd be experimenting with that tablet using my own fleshy stylus. Assuming you have one.
    • >My Wacom tablet does it but my hand has to be pretty close to it to feel anything

      I dont think the tablets create anything yuo can actually feel. Hell, the tablets are passive, the actual power is in the pen with the battery. Chalk this up to being psychosomatic. I used to believe I could feel wifi signals if they were too close to my head. Doing a blind test proved I was wrong.

      Maybe things are different nowadays with the battery free pen. Still, thats really a small amount of energy.
  • I see a lot of sparks when i use wool blankets and a acrylic t-shirt, maybe thats what started this project?

  • http://hardware.slashdot.org/article.pl?sid=07/04/ 30/1630217 [slashdot.org]

    Article references to University of Tokyo and organic molecules as well.

  • 1. What are the power losses like?
    2. Will it give me brain cancer?
    • 1- Not that bad, since the system is supposed to only power the area where power is required. Of course, it's hard to beat a good old AC/DC converter.
      2- No risk. EM field have been studied for long, and such a low power quasi static field is way below things known to be harmless. Plus, since the field is supposed to be located only where it is needed and not all the time in the whole room, it won't probably not even reach you. Using an electric shave will probably send more EM radiation to your head.

      • Re: (Score:1)

        by maxume ( 22995 )
        Don't you mean modern AC/DC converter? The nice adapter for my laptop is barely bigger than the janky one for my cell phone.

    • Re: (Score:1)

      by Mythrix ( 779875 )
      1. What are the power gains?
      2. Will it give me superspeed and/or ability to manipulate electricity at will?
  • I cannot find any reference, however I recall reading an article several years ago which detailed a consumer deskpad which contained dozens of micro contacts. The idea was you simply lay your laptop, mobile phone, pda on the pad, and it begins to charge. Of course this product assumed that your devices were outfitted to use the charger. A microcontroller would actively sense the current between pad contacts, allowing charging, but preventing short circuits. Again, as I cannot locate this product now, I

  • A Victorian Idea! (Score:3, Interesting)

    by Goth Biker Babe ( 311502 ) on Friday May 04, 2007 @09:05AM (#18986897) Homepage Journal
    Lord Armstrong, a Victorian inventor and armaments manufacturer had one of, if not the first, electrically lit house in the work. Cragside" [wikipedia.org] was lit (initially by carbon arc lamps but then by Joseph Swan's incandescent light bulbs) powered by hydroelectric power. During the day horses pumped water to a lake up the hill side. During the night that water generated electricity.

    The table lamps replicated old oil lamps in style but had spikes which poked in to table clothes which were threaded with copper wire carrying current. This meant you could carry them around, put them down, and they would just light.
  • So if I wear gingham trousers I can use my laptop on my lap without having to plug it in? Fantastic.
  • Induction - doesn't this mean your hair will stand on end whenever you're holding cutlery? Or is the field too weak/short-ranged for humans to notice?
    • You won't notice anything because 1- it is too weak and 2- you don't have enough metal in your body to be affected even by strong magnetic fields anyway, and BTW, it is not induction but static charge that makes your hair stand on end.
  • The first great add-on I see to this is the ability to crank up the current and voltage so that all the people at the conference table are shocked into paying attention. Too many people brings their Notebook PC's to meetings, and then they glue themselves to the screens. Answering instant messages, typing notes, playing games, who knows what! And they all clamor for the plug because they all seem to be low on power...

    With this, they can be 'charging' and also 'shocked' when needed...
  • I saw a TV Program about something Phillips developed a few years ago, for the kitchen of the future. They showed a table cloth that you could put electric candles, heated plates, and even a food tester on.
  • Just get a wool tablecloth, a dozen hamsters running in circles with cables in their mounths and you'll get the same effect.

    I'd be willing to try this out with my laptop. Aero on my Vista eats the battery so if this'll give me power without cords..woo hoo!

  • Induction is nothing new. Submersible waterpumps use inductive impellers. Every chemistry lab I've ever been in has used both inductive mixers and inductive heaters. This is all established, stable technology.

    Even inductive charging is nothing new - I've had a toothbrush that does this for years.

    So when I read articles about inductive mats saving me from my rat's nest of cables, don't think I'm not enthusiastic about the prospect. My concern, though, which I haven't yet seen addressed adequately, is what

    • Re: (Score:2)

      by geekoid ( 135745 )
      YOu do know that hard drives have powerfull magnets in them, right?

      I seriously doubt this gives off a strong enough magnetic force to damage your equipment.

      • YOu do know that hard drives have powerfull magnets in them, right?

        I do, actually. I also know that, as part of the device, the fields the generate are taken into account when designing the device.

        Floppy drives have their own magnets, too, but I have never seen a disk erased by such. I have seen a disk done in by environmental EM, though.

        I seriously doubt this gives off a strong enough magnetic force to damage your equipment.

        Perhaps not. I hope not. Still, it's enough for me to wonder, and want to proceed with caution.

  • There's a company commercializing a similar concept called splashpower [splashpower.com]. I don't work for them, although I have worked with them. It's really cool technology and, suprisingly enough, it's not vaporware.

    Hopefully they'll actually have their modules out for public use sometime soon...
  • I don't see this so much as an 'electric tablecloth' concept rather an inlay for pressboard style tables (large conference room tables come to mind)..if these are manufactured to a standard spec, then all that needs to be done for each individual device is a receptor to take that power source and convert it into the voltage/ampereage necessary for that device. Another neat use for it would be a mousepad for your wireless mouse to keep it charged all the time..just imagine, being able to game with a wireles
  • Women's stilletto heels are made with steel spikes.

    Have you ever been in a ground-floor office where the electric power was run over the concrete floor below the carpet, without trenching the concrete? And if you've worked in an office like this you know that women's high heels tend to drive that steel spike down into the material and cause an explosive short across the damp concrete.

    Best not use your electric table cloth in the wrong kind of establishment. Spill a beer, go to jail!
  • Magnetic fields fall of as the CUBE of the distance, so don't expect this tablecloth to be all that useful. It will probably require no more than a centimeter between the sending and receiving coils, possible less. Also note that any uncaptured power ends up being dissipated in the sending coil, so it will make a nice heating pad for your sore muscles. If you don't mind a magnetic field going into you as lagniappe.
  • wouldn't it be great if you had a small stand that you could mount on the wall or put on your desk, where you would put your cell phone, pda, and other gadgets? Between me and my wife we have 2 phones, two pda's, game boy ds, wireless mice, mp3 player etc.. and all the matching (and different) wall warts to charge them.

    How about also building in the ability to communicate when on the pad? That way your pda or cell phone could automaticaly sync when on the pad. How about mouse pads that charge the mouse?

    H

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