Tiny Nuclear Batteries to Power Micro Devices

[n2doc]

By Jeremy Hsu, Special to TopTenREVIEWS
posted: 09 December 2009 09:59 am ET



Typical chemical batteries just don't cut it when a device needs to run for years without fail. Enter the betavoltaics, or tiny nuclear batteries that harvest energy from radioactive sources such as tritium.

Now a company called Widetronix has developed new betavoltaics that can run for up to 25 years and perhaps power tiny devices in everything from military hardware to smartphone sensors.

Nuclear in this case does not refer to fission power and splitting atoms, but instead means the natural decay of electrons given off by radioactive sources. A semiconductor such as silicon harvests the decaying electrons in betavoltaics — similar to how semiconductors in photovoltaic cells collect photons from solar energy.

more:

http://www.livescience.com/technology/091209-nuclear-batteries.html

[JonQ]

1. Neat

I am concerned that with the word "nuclear" in it many of the scientifically illiterate folks will have . . . well . . . the usual response to anything with the word nuclear in it.

You're going to put atomic bombs in batteries! And put those near my children!

[bananas]

2. nanowatts

This doesn't really belong in the E/E forum.
The Science forum would be a better place.

[joshcryer]

9. There was a guy who claimed to be able to make batteries using this mechanism.

Batteries that would power a laptop for 20 years. It was on slashdot and the posters noted how asinine his "battery" was and that it simply wouldn't work. He was found to be a crackpot in the end.

But yeah, this probably belongs in Science more so than E&E.

[lapfog_1]

3. We used to make watches with radium on the hands

which would glow in the dark while the radium decayed.

Which it would for a few thousand years.

http://www.periodictable.com/Elements/088/index.html

Here is a good quote from this article:
"Radium was widely used in self-luminous clock and watch hands, until too many watch factory workers had died of it."

Not that this is the same, just pointing out that we've had a checkered past with using radioactive devices in the past.

[drm604]

4. They died because they painted the radium on the watch dials,

and used their mouths to bring the paint brush to a point, and got bone cancer in their jaw because of it. We know better than that now.

[lapfog_1]

5. Yup, we won't die from THAT again.

Next time, it will be something else.

[drm604]

6. I'll grant you that that's a possibility.

But it's a possibility with any new technology (and even some old ones.) Does that mean that we should stop all progress?

Hell, we'll probably at some point find some unexpected dangers and unintended side-effects from things like solar and wind power. Does that mean that we shouldn't go forward with them? Absolutely not.

We need to weigh the risks and regulate sufficiently and then proceed... with caution.

[lapfog_1]

7. Nope, but the general problem of radioactive materials

is now understood, perhaps we should think of other technologies.

The amount here is tiny, but some radioactive material is poisonous even in very tiny amounts.

And, as we have seen over and over again, regulations on corporations often fail when they conflict with profit motive.

[wtmusic]

10. Tritium is probably less harmful than the chemicals used in a lead-acid battery

"Tritium is a naturally occurring radioactive form of hydrogen that is produced in the atmosphere when cosmic rays collide with air molecules. As a result, tritium is found in very small or trace amounts in groundwater throughout the world. It is also a byproduct of the production of electricity by nuclear power plants.

Tritium emits a weak form of radiation. The radiation emitted from tritium is a low-energy beta particle that is similar to an electron. Moreover, the tritium beta particle does not travel very far in air and cannot penetrate the skin.

How do people become exposed to tritium?

Tritium is almost always found as a liquid and primarily enters the body when people eat or drink food or water containing tritium or absorb it through their skin. People can also inhale tritium as a gas in the air.

Once tritium enters the body, it disperses quickly and is uniformly distributed throughout the soft tissues. Half of the tritium is excreted within approximately 10 days after exposure.

Everyone is exposed to small amounts of tritium every day, because it occurs naturally in the environment and the foods we eat. Workers in Federal weapons facilities; medical, biomedical, or university research facilities; or nuclear fuel cycle facilities may receive increased exposures to tritium.

Is the radiation dose from tritium any different than the dose from natural background radioactivity or medical administrations?

The type of radiation dose from tritium is the same as from any other type of radiation, including natural background radiation and medical administrations.

The tritium dose from nuclear power plants is much lower than the exposures attributable to natural background radiation and medical administrations.

Humans receive approximately 82% of their annual radiation dose from natural background radiation, 15% from medical procedures (e.g., x-rays), and 3% from consumer products. Doses from tritium and nuclear power plant effluents are a negligible contribution to the background radiation to which people are normally exposed, and they account for less than 0.1% of the total background dose (NCRP, 1987)."

http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/tritium-radiation-fs.html

[struggle4progress]

16. The quantity of cosmic-ray produced tritium is rather small:

... The world wide production of tritium from natural sources is 4 x 106 curies per year with a steady state inventory of about 70 x 10^6 curies ... The specific activity of T2O is 2,700 Ci/g ... http://www.physics.isu.edu/radinf/tritium.htm

So if the naturally produced T were all captured as HTO, one would have just under 50 kg (only a bit more than 100 pounds) of HTO -- perhaps a total global inventory of 7.5 kg (16 pounds) of natural T

[drm604]

11. They've worked with small amounts of radioactive materials in hospitals for a long long time.

Their may have been an incident of some kind here and there but I've never heard of a major problem.

Tritium, the isotope mentioned in the article is already in use in commercially available products.
http://en.wikipedia.org/wiki/Tritium

Self-powered lighting
A tritium illuminated watch face
Main article: Self-powered lighting
The emitted electrons from small amounts of tritium cause phosphors to glow so as to make self-powered lighting devices called betalights, which are now used in watches, exit signs, and a variety of other devices. This takes the place of radium, which can cause bone cancer and has been banned in most countries for decades. Commercial demand for tritium is 400 grams per year.

Firearms night sights
The radioactive decay of tritium is used in firearms night sights in much the same way as the clock hands discussed above. The electrons emitted by the radioactive decay of the tritium cause phosphor to glow, thus providing a long lasting (several years) and non battery powered firearms sight which is visible in dim lighting conditions. The tritium glow is not noticeable in bright conditions such as during daylight however. As a result, some manufacturers have started to integrate fiber optic sights with tritium vials to provide bright, high-contrast firearms sights in both bright and dim conditions.

I agree that corporations can't always be trusted, but if we allow that fact to rule us then we would have to stop the production of all potentially dangerous materials and that would pretty much put an end to a large number of our day to day technologies.

I think you're making the mistake of assuming that all nuclear technologies are inherently too dangerous to deal with. There are different levels and kinds of radioactivity and different kinds and amounts of radioactive materials.

Nobody's suggesting nuclear reactors in people's basements here. They're suggesting amounts of material that, from what I can see, are less than the amount you have in your smoke detectors.

[lapfog_1]

12. No, I'm suggesting that we, as a race, exhibit hubris

and, worse, when profit motive is inserted into the equation, corporations can't be trusted.

Now it all might be perfectly safe... and I'm sure that it is... but I, for one, don't stick my cell phone handset up to my ear (I use a bluetooth earbug). And I try not to eat GMOs. I even limit the amount of beef, pork, chicken, or fish that I eat due to a number of man made issues with those products (hormones, mercury, etc). Yes, there is risk in all we do, but all too often we don't fully understand the risk until it's too late.

Example: My father worked in the Navy for 20 years, quite a number of those were aboard ships and, as part of shake down crews, sometimes in the ship building yards. He died from Mesothelioma some 15 years ago now, probably 10 to 20 years before "his time". They showed me an X-ray of his lung where there was this bright spot, with little tendrils radiating around it. That was asbestos. But back in the 40s and 50s, it was thought to be "perfectly safe".

Now, of course, we know better. But do we really? I'm not a luddite, in fact, I worked for NASA for many years (right on top of a superfund site), but I do have a healthy amount of doubt about "new whizzy" stuff.

[drm604]

13. What can I say. Everything was "new whizzy stuff" at some point.

No doubt in the future we'll discover that some things we currently consider harmless are causing some kind of problem for some people. But are we to suddenly give up on anything new because we live in an imperfect world? I would maintain that, at this point in history, giving up on progress would be more dangerous than not. At this point the human race, if for no reason other than our sheer numbers, requires technological progress to simply continue to warm and feed ourselves without destroying our biosphere.

That progress will almost certainly contain some nasty surprises here and there, but what's the alternative?

[lapfog_1]

14. Precisely,

everything was "new whizzy stuff" at one point. So.. what's the take home lession. Slow down. Don't use materials to build things that have proved to be dangerous when used in something else. Stuff like that.

And make sure those regulations are reviewed and enforced.

[drm604]

15. I could be wrong but I don't think that there have been many problems with tritium.

You're concern is about an incident with radium, a totally different material. We don't totally avoid acetic acid (vinegar) because of the dangers of sulfuric acid. Do we avoid all radioactive materials because of the dangers of the worst of them?

[madokie]

8. Won't be using this on my yard cart any time soon, sounds like

it would be cool for what it would be good for though