Thin, Flexible Printable Battery For Smartcards

cornflux writes "This would be a nice way to power a really smart smartcard: Power Paper, Ltd. has created an alkaline-like energy cell that is (among other things) thin, flexible, and "green." Furthermore, it is printable via a silk-screening process onto paper, plastic, and other flexible materials. ABCNEWS.com has the story."

Comments

Re:Replacement

[ho11yw00d]

At roughly $22 for the equivalent power of a AA, I doubt that they will add these to anything that doesn't absolutely require them.

Power/weight ratio

[vlad_petric]

To produce as much power as a standard AA-sized battery, for instance, would require a Power Paper battery of about a square foot in size.

It's pretty obvious that the power/weight ratio of this type of battery is significantly smaller than the one of a standard AA batery. More than that, the article fails to mention the exact capacity or stand-by leaking current. Which pretty much means that the average lifetime of such a battery is inferior to the one of a regular battery (if it were superior, I'm sure they would have mentioned it).

The Raven

Quite nice...but...

[MasterOfDisaster]

Here's a few problems i see with this thing:
* Not much power. 1/22 of an AA batt. wont power much for very long. even LCD screens are rather power intensive. and since it has a rather high cost, wouldnt we have to pay for replacement creditcards quite often?
* Not rechargeable (is it?) You'd either have to replace the entire device or recharge the paper, when the batt. dies. These dont seem too replaceable, they're far too propritary/embedded

Aside from that...I could see all kinds of fun uses for this..especialy when combined with e-ink...You could have, for example..a reuseable newspaper. Hell, make it glow while we're at it. The use this will probly be put to is however some sort of tracking system. Build a little antena into my new smartcard, and Amex can tell exactly where I am at all times. If you put it into my drivers licence, so could the goverment. Fun, aint it?

Re:Battery life

[Karma 50]

If my maths is right - 25 hours at standard drain

http://www.powerpaper.com/tech/technology.html

Nominal current 0.1 mA/cm2
Capacity 2.5 mAh/cm2

Shelf life is 2.5 years.

So between 1 day and 2.5 years depending on usage.

Power Supply Cryptanalysis

[burris]

Unfortunately, information about what the smart card is doing is leaked through the power supply. Giving the smartcard it's own internal power supply can help prevent power analysis attacks from the reader itself. By eliminating an input/output, the black box of the smart card can be made that much "blacker."

burris

Re:patent issues..

[Karma 50]

They have a patent. 5,897,522.

The patent seems to be for a mechanism for allowing the escape of gases produced by the generation.

They give some examples of chemicals in the patent application and the chemistry of batteries of old technology, there are probably a number of different solutions that could be used.

They could be protecting the exact chemicals used just because they're an efficient set to use, not because they're the only ones which work; and the real invention is making the whole thing practical and long-lasting.

What about "smart books"?

[MsWillow]

One reason that ebooks haven't taken off yet is that it's rather cumbersome, carrying your laptop all over creation just to read a book. Using this as a power source, and a single-page lcd screen, you might just have an ebook that was portable enough to carry around like a regular paperback.

The battery is replaceable, and it shouldn't be hard to download different texts into it... or, maybe, store the texts on a novram card. Sell whole textbooks like this, and make it easier for students to carry the whole load.

These paper batteries could easily be used, whereas conventional batteries are rather heavy and bulky, still.