Tiny nuclear battery

University of Missouri engineers are building a nuclear battery the size of a penny. Their aim is to develop a long-lasting power source for tiny sensors, actuators, and labs-on-a-chip. While nuclear batteries sound, er, problematic, they're actually relatively common in larger form factors to power pacemakers and instruments aboard space vehicles. From MU News Bureau:
 News Stories 2009 Nuclear-Battery-Outstanding-At-Conference Images Microbattery-Edit Lg (Professor Jae Kown's) innovation is not only in the battery’s size, but also in its semiconductor. Kwon’s battery uses a liquid semiconductor rather than a solid semiconductor.

“The critical part of using a radioactive battery is that when you harvest the energy, part of the radiation energy can damage the lattice structure of the solid semiconductor,” Kwon said. “By using a liquid semiconductor, we believe we can minimize that problem.”

In the future, they hope to increase the battery’s power, shrink its size and try with various other materials. Kwon said that the battery could be thinner than the thickness of human hair.
"MU Researchers Create Smaller and More Efficient Nuclear Battery"



  1. “University of Missouri engineers are building a nuclear batter the size of a penny. ” Are they gonna make cupcakes with that batter?

  2. Saying that nuclear batteries are “relatively common” in powering pacemakers is misleading: no nuclear pacemakers have been made since the mid 1980s, and as of 2005 only a handful were still in operation.

    Assuming that these are miniaturized RTGs (Radioisotope Thermoelectric Generators), since that is what powers nuclear pacemakers and spacecraft, there is still a big problem: Plutonium-238. First of all, Plutonium is the sixth most toxic material known to man. Second, it bursts into flame when it contacts air, spreading around fine radioactive dust. Third, and most important, we are quickly running out of it.

    The US has not produced plutonium since 1988, and plans to build a new breeder reactor in 2005 were scrapped. Our remaining stockpiles are already spoken for to power three upcoming space missions, but when that’s gone it’s gone. See http://www.npr.org/templates/story/story.php?storyId=113223613.

    Yes, there were other nuclear batteries that weren’t plutonium based, such as Promethium-147, but the half-life of promethium is only 2.6 years, giving a lifespan comparable with lithium batteries.

    1. Are you sure they don’t still use that expensive, unstable and highly toxic stuff for pacemakers? I can’t think of a more fitting substance for powering Cheney.

  3. @Zan – You are right that nuclear powered pacemakers never really caught on. Chemical battery technology and other efficiencies made them unneeded. They were NRC licensed devices which meant that, upon death, someone would track down your body and cut it out to ensure proper disposal ;-)

    You are wrong about this ‘sixth most toxic material’ nonsense. Where did you come up with that? Usually plutonium is called ‘most toxic’ but that is still BS. Toxicity doesn’t neatly rank into some kind of Letterman Top Ten list. It depends on form, quantity, kind, etc.

    Plutonium does not burst into flames in contact with air. Sorry.

    If you understood how nuclear batteries work, you would know that there are many different isotopes that can power them.

    I’ll bet this one uses Nickel-63. It is available from spent nuclear fuel (currently garbage…so it is cheap as far as radioactive stuff goes), has no chemical toxicity in the body (not a heavy metal), has a nice 92 year half life (not too long, not too short on a human timescale), and is a pure beta emitter (when it decays, you get an electron…convenient for generating electricity!), and it decays directly into Copper-63 which is stable (no messy leftovers).

    You would also know that chemicals like plutonium and uranium are more dangerous to the body because they are heavy metals…not because they are radioactive.

    All that said, I’ll betcha this never goes anywhere. Sensors that can generate power from ambient vibration, daily temperature shifts, or small lithium cells will fit the bill moving forward.

    Too bad, cause it is neat.

  4. @ Zan, amuderick:

    I have on pretty good authority that one of the US’s largest manufacturers of implant devices is actively researching and prototyping new nuclear battery packs for upcoming models, so at least from that perspective, this work is more relevant than it may seem otherwise.

  5. And they’ve almost figured out how to eliminate the problems with surgically implanted lead shielding!

  6. Meh, if it’s a pure beta emitter your own skin is overkill to shield the radiation, iirc you can pretty much shield beta radiation with a business card.

  7. As amuderick points out, these miniature nuclear batteries are not RTGs. They simply can’t be, at that size. Nuclear batteries of this sort use tiny amounts of beta emitting radionuclides. Beta radiation is merely electrons, which can be absorbed and used to generate a tiny electrical current. Note that these are very low power batteries, their main advantage is that they produce a steady current for decades.

  8. AirPillo, you’re confusing beta with alpha. Alpha particles can’t penetrate a piece of paper, though you can still get lung cancer if you inhale an alpha emitter. But a beta particle (high energy electron) can penetrate a few inches of wood.

  9. Oh shoot, I did mix up alpha and beta. I should know better, too.

    Well, time to go dig out my textbooks and do some review!

  10. Very interesting article and even more interesting/intelligent comments (for the most part). No trolls, what a refreshing change.

  11. I have a key fob called a “Traser Glowring” that contains a tiny amount of tritium (H2 isotope) gas in a phosphor-coated glass tube encased in plastic. It creates a glow which, though dim, is quite visible in the dark. The tritium has a half-life of 12.3 years. I have heard of ideas based on this (tritium -> phosphors -> micro-photovoltaics) to create long-lasting batteries for very small loads. Tritium is ideal since it is a low-level beta emitter (easily shielded against) and, if the container is broken, it disperses harmlessly into the atmosphere.

  12. @Zan,

    What treehugger site did you get your “facts” from? Plutonium does not combust in open air. And please don’t quote NPR; they usually are half-right when it comes to these kinds of things.

  13. In response to Zan, the isotope they are using is NOT plutonium it’s “sulfur-35 isotope”. I’m not a nuclear physists, but perhaps this addresses your issue.

  14. the possibility of nuclear battery for heavy transportation vehicles, i.e. municipal solid waste trucks and public buses???
    Does it exist, does it function?? This would mean a life log lasting battery not needing recharge.
    Norway Calling!!

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