Energy management

I've been looking at this technology for awhile, since I saw this article in
IEEE . The
Widetronix solution seems a little more straightforward, since it electronically
harvests the charge rather than using the charges to drive a piezoelectric
device that then generates electron current.

What I find scary about it is the thought of it going into consumer electronics
that are designed for short life cycles. Fortunately, the technology is nowhere
near to powering a cell phone for instance.

There is also a very good article on betavoltaics at NextBigFuture.


Tiny Nuclear Batteries to Power Micro Devices
livescience.com – Sat Dec 12, 7:11 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 electrons in betavoltaics - similar
to how semiconductors in photovoltaic cells collect photons from solar energy.

Microwatts envisioned
The first betavoltaics began by using silicon semiconductors over 50 years
ago. But Widetronix has created silicon carbide semiconductors which appear as
tiny chips, and can function for years while resisting radioactive damage.

"It is our professional opinion that the higher the efficiency, the lower the
device cost, and the smaller the unit volume," said Jonathan Greene, CEO of
Widetronix in Ithaca, New York.

Keep in mind that these won't run your netbook or even iPhone anytime soon.
The betavoltaics currently only provide nanowatts of power, where one nanowatt
represents a billionth of a watt. But Widetronix has already begun experimenting
with stacking chips together to create a nuclear battery that can provide a
microwatt of power, or one millionth of a watt.

Such tiny power sources could enable a growing swarm of tiny devices in
civilian life. Greene said that his company is looking toward "ultra low power
implantable devices" that might help physicians monitor the health of patients.

Supporting MEMS and the military
The growing popularity of Micro-Electro-Mechanical Systems (MEMS), which
enable "systems-on-a-chip" and other electronic devices on incredibly small
scales, could also benefit from betavoltaics. They may help transform smart
phones into do-all devices that monitor human health and the environment.

"In general, the opportunity space is around wireless sensors - working with a
host of complimentary power storage and energy harvesting technologies," Greene
told TopTenREVIEWS. "Betavoltaics in my view can be at the heart of the system
providing long life reliability and small size."

The U.S. military also likes what it sees in betavoltaics. Lockheed Martin has
already begun testing some of the Widetronix batteries for use in anti-tamper
military devices, which prevent enemies from tinkering with missiles or other
sensitive military hardware. More powerful betavoltaics could someday power
devices that help U.S. commanders keep track of their warfighters, aircraft,
vehicles and drones.

Back on the civilian side, Greene says that betavoltaics-powered sensors could
monitor the condition of bridges, roads and buildings. Commercial airline fleets
might also use such sensors to alert mechanics about when an aircraft requires
maintenance.

Widetronix still wants to examine new nuclear isotopes, such as
Promethium-147, as sources of more power in future batteries. But the first
commercial products are already slated for rollout sometime in 2011 - most
people just probably won't notice the tiny batteries powering their devices.