A New Wireless Power Transmission Sheet

Roland Piquepaille writes "Several companies have started to sell power 'pads' that can charge your cellphone when you put it on the pad's surface. But these silicon-based pads are expensive — and relatively 'specialized.' Now, Japanese researchers have built a plastic sheet which could power all the devices placed close to it. So far, this 4-layer sheet, which uses printed organic transistors and plastic MEMS switches, can deliver up to 40 watts of power — enough for some laptops. The technology is apparently efficient and inexpensive to produce. But as the devices to recharge will need to incorporate a special receiver, don't expect to see these plastic power sheets on sale before several years."

Comments

i remember this

[brunascle]

i remember this. good to see it's making its way to the market.

Re:i remember this

[jusDfaqs]

Oh yea, Tesla was playing with this a while back :-)

Re:i remember this

[OldeTimeGeek]

If the brush that they're using is a Sonicare, there aren't any contacts - it uses inductance.

Re:40 watts?

[fiftysixquarters]

Do you really want Sony powering your laptop?

Re:This is stupid

[drinkypoo]

Sorry to be blunt, but this is just stupid. Plug your phone into the little wire, and be done with it.

If you were right, bluetooth would not exist, and we'd just use the little wire.

but you're wrong. wires are a bitch. and now that you can transfer the data wirelessly, it's highly desirable to be able to transmit power wirelessly as well.

This is also absolutely necessary in a hospital setting; currently you have to have covers over all ports. Eliminate the ports, eliminate the covers, make the device more fluid-resistant, it's a win-win-win situation.

Aftermarket receivers will come first...

[TBone]

Just like every Chinese fab is making electronics accessories for laptops and cell phones and such, expect that, if these things get cheap enough, we'll start seeing adapters to clip onto the bottom of phones that will take power from the pad.

Shortly after that, expect to start seeing universal adaptor kits at Radio Shack with a switch-selector voltage output, and 87 plugs, to connect to a generic charger. Maybe a charger base with 3 outputs.

The application for such a pad is MUCH larger than the article implies. It won't require manufacturers to integrate such receivers until well after their acceptance, which will drive down the price per unit to incorporate them into devices.

How Efficient?

[FroBugg]

The article gives some efficiency numbers, but doesn't explain exactly what they're talking about.

The researchers say the transmission of power happens with 81.4% efficiency -- compared to 93% efficiency in the wired grid network as a whole -- with a "quite low" level of leaked electromagnetic radiation.

Now, I may be wrong, but I believe that 93% is the efficiency of electricity being generated at the power plant and then sent to you, however many miles away. So it's not an either-or thing, it's an extra loss. Instead of losing 7% of the generated electricity, you lose nearly 25%. This is ridiculous compared to the effort of just plugging your damn devices in.

Re:How Efficient?

[Big_Breaker]

Wall warts are probably worse for wasting energy, especially since they stay plugged into the wall even when the gadget is not recharging. That burns energy 24/7.

One pad - even with transmission losses - is probably better than the typical 3-6 wall wart chargers in use at a given time.

Re:How Efficient?

[hotdiggitydawg]

And all it's doing is charging cell phones or mp3 players, it would be on for only a few hours a day, at most. Rubbish. Its sole purpose for existence is the convenience/laziness of not having to plug your device in. Do you seriously think anyone lazy enough to want such a charger will bother to turn it off? And "standby" mode is largely useless in cheap electronic goods from an environmental perspective.

Additionally, it is only 40 watts now. Who's to say it won't be capable of, say, 1000 Watts in a few years time? Wireless kettle/microwave, anyone?

Re:How Efficient?

[FroBugg]

http://www.inference.phy.cam.ac.uk/sustainable/cha rger/

Re:How Efficient?

[Sandbags]

First, the pad only "uses" electricity when there is a device inside of it's field of effect. There's no "sleep mode" it just doesn't use any mower when nothing is near it. The magnetic field generated can easily sense the presence or lack of a device and power on only when necessary.

Second, if you understood the technology, you would know there will never be a 1000 watt version. Magnetic field science works on a multiple of squares system. To generate 80 watts instead of 40 takes a field 4 times larger. to go to 160 watts requires 16 times as much field density. To produce induction coils capable of generating a field large enough to charge large devices, or a field strong enough to charge high voltage devices is prohibitively expensive.

Third, this is a trickle charge technology, taking most of the night to recharge your device instead of an hour. When batteries are rapidly charged, they get hot. This heat is not only energy wasted, but inhibits charge efficiency. Charging times for electric cars are the primary reason they don't exist yet. Trickling the energy into the battery keeps the resistance low, prolongs battery life, and actually makes each charge last longer (rapid charging only gets batteries to about 85% capacity, trickling get it to 100%).

The power efficiency of induction pads is actually quite amazing. 2% on average power loss. In fact, the pad will usually be much MORE efficient that a wall charger since the charger in the wall is 1) always using some power when plugged in, 2) still has 1-2% or more power loss when charging, 3) completes its charge in 1-2 hours, but typically remains plugged in and wasting energy (although not much) for 8-10 hours.

Smart induction only applies power to devices who's antennae resonate on specific frequencies. If you have multiple devices charging at once, the pads can resonate on multiple frequencies at the same time, charging several devices. When one completes its charge, the pad can stop "broadcasting" on that frequency and thus stop wasting that power.

Little plastic pad

[CaptainPatent]

Sure it's cool to charge your gadgets with a little plastic pad, but I contend it's more fun with a Tesla coil

Oblig: Pls tag 'ohnoitsroland'

[siglercm]

Another Roland article. Time to rack up more advertising hits....

Please tag as 'ohnoitsroland' -- thank you :)

Re:40 watts?

[Red Flayer]

Do you really want Sony powering your laptop?

I'm all for Sony implementing this.

Think about it -- when the charging device explodes, there's a chance that your laptop will be blown clear and suffer no harm.

Re:This is stupid

[xenotrout]

Sure, this sheet does require a wire, but that wire can be plugged in once and left connected. Especially useful if many devices can be charged by one pad. In the case of charging and powering mobile devices, the wire isn't as bad as having to plug it in and unplug it, possibly keeping track of multiple plugs and wires. Minor difference for a single device but a larger difference for multiple devices.

Ye Another Ridiculouxs Tesla Power Idea

[Ancient_Hacker]

Folks, *think*. People worry about microwave ovens leaking milliwatts.

Here someone is suggesting letting free many watts.

Just ain't going to ever be approved.

It doesn't take much power, under a watt, to make instant cataracts. Ask any old radar operator.

Re:40 watts?

[mobby_6kl]

My laptop's PSU is rated 2.7 A at 18.5 Volts, and that must be with a good safety margin. Then agian, it's an almost six-year-old, 600Mhz P!!!-M machine, with 3D Rage Pro for video and an 11" screen.

Mordern laptops, judging by the replacement PSUs available, seem to fall between 65-100W, although one Acer unit is rated at 135W.

Re:This is stupid

[drinkypoo]

What is Bluetooth used for? To eliminate wires? Are you serious?

what did you think it was for? eliminating macramé tea cozies?

Re:Environmental reasons why this is stupid.

[zippthorne]

20% of your power.. for LOW POWER DEVICES.

They're not talking about running a refrigerator for these things, they're talking about reducing wall-wart clutter to one wire and one pad. In addition to less clutter, that means that lazy people will leave fewer transformers plugged in without powering anything.

Re:This is stupid

[FrankieBaby1986]

Wouldn't simply using one adapter for all your devices suffice? If cellphones, pda's etc would STANDARDIZE their power adapters (they won't, so cingular, LG, etc. can continue charging $30!!! for a cellphone charger!) to a standard form factor and voltage, then you could use one, more efficient, auto switching power supply. Then a simple daisy-chain style connector could be created, and bingo, less mess. Devices would simply require a diode-square (polarity protection) and a voltage regulator. Then a simple, two or three pin system could be made (5 and 12 volts). Thus eliminating multiple wall-warts, allowing for daisy-chain or octopus charging, etc. Each extension wire would have a male+female end. This would allow for both chaining and octopus connections. Less loss due to transmission losses, less potentially harmful EM radiation, etc.

Re:This is stupid

[GlL]

In his essay WALDO, Robert Heinlein (ahead of his time again), (link to a synopsis http://www.wegrokit.com/jmwami.htm), raises some concerns regarding the health implications of this type of technology. With all of the radiant energy that we are already pumping through ourselves, what are the health implications of this technology? This won't be adopted in my house until the health implications are sufficiently addressed.