Stories
Slash Boxes
Comments

SoylentNews is people

posted by on Wednesday January 04 2017, @05:06PM   Printer-friendly
from the light-excitation dept.

The notion of using solar cells placed under the skin to continuously recharge implanted electronic medical devices is a viable one. Swiss researchers have done the math, and found that a 3.6 square centimeter solar cell is all that is needed to generate enough power during winter and summer to power a typical pacemaker. The study is the first to provide real-life data about the potential of using solar cells to power devices such as pacemakers and deep brain stimulators. According to lead author Lukas Bereuter of Bern University Hospital and the University of Bern in Switzerland, wearing power-generating solar cells under the skin will one day save patients the discomfort of having to continuously undergo procedures to change the batteries of such life-saving devices. The findings are set out in Springer's journal Annals of Biomedical Engineering.

Most electronic implants are currently battery powered, and their size is governed by the battery volume required for an extended lifespan. When the power in such batteries runs out, these must either be recharged or changed. In most cases this means that patients have to undergo implant replacement procedures, which is not only costly and stressful but also holds the risk of medical complications. Having to use primary batteries also influences the size of a device.

[...] To investigate the real-life feasibility of such rechargeable energy generators, Bereuter and his colleagues developed specially designed solar measurement devices that can measure the output power being generated. The cells were only 3.6 square centimeters in size, making them small enough to be implanted if needed. For the test, each of the ten devices was covered by optical filters to simulate how properties of the skin would influence how well the sun penetrates the skin. These were worn on the arm of 32 volunteers in Switzerland for one week during summer, autumn and winter.

No matter what season, the tiny cells were always found to generate much more than the 5 to 10 microwatts of power that a typical cardiac pacemaker uses. The participant with the lowest power output still obtained 12 microwatts on average.

Journal Reference:
L. Bereuter, S. Williner, F. Pianezzi, B. Bissig, S. Buecheler, J. Burger, R. Vogel, A. Zurbuchen, A. Haeberlin. Energy Harvesting by Subcutaneous Solar Cells: A Long-Term Study on Achievable Energy Output. Annals of Biomedical Engineering, 2017; DOI: 10.1007/s10439-016-1774-4

-- submitted from IRC


Original Submission

 
This discussion has been archived. No new comments can be posted.
Display Options Threshold/Breakthrough Mark All as Read Mark All as Unread
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
  • (Score: 2) by VLM on Wednesday January 04 2017, @07:04PM

    by VLM (445) Subscriber Badge on Wednesday January 04 2017, @07:04PM (#449478)

    The math... something feels weird here.

    A genuine 18650 weighs a hair under 50 g and looks like a AA battery and stores almost exactly 10 watthours (the fakes on ebay are much lighter and store much less energy, although they supposedly make up for it by catching on fire much more often). Those are easy figures to remember and I checked and they're even mostly truthful. Close enough to 1 sig fig for engineering purposes...

    If the power drawn is 5 to 10 u-watts thats 114 years between charges on a 10 Wh battery, worst case. More like 228 years best case.

    More likely you could implant something 1/10 the size of a 18650 (which is already pretty small indeed) and charge it every decade or so with a wireless Qi charger like my phone uses. Lets say 50% efficient and 5 watts rate thats two tenths of an hour of charging every decade. Now you can't charge a small cell that fast in only 12 minutes without shortening lifespan quite a bit, but the point is we're not talking about powering a Tesla 0-60 in two seconds or whatever here.

    I suppose a lithium battery fire inside your chest cavity might be problematic. Still, a much lower tech battery a tenth as efficient and implantable the size of a medium turd or large tumor should be implantable in the innards without too much difficulty that would run a pacemaker for a century without charging.

    There must be more to story. Like the entire power unit is encased in 1/2 inch stainless steel to protect against fire and gunshots, or the numbers in the story are milliwatts not microwatts, or when I was a kid pacemakers were the size of a deck of cards and now they go in via a tiny catheter hole instead of chainsawing the entire chest apart, I think there's more to the story....

    Starting Score:    1  point
    Karma-Bonus Modifier   +1  

    Total Score:   2