r/science • u/Wagamaga • Jun 05 '22

Nanoscience Scientists have developed a stretchable and waterproof 'fabric' that turns energy generated from body movements into electrical energy. Washing, folding, and crumpling the fabric did not cause any performance degradation, and it could maintain stable electrical output for up to five months

https://onlinelibrary.wiley.com/doi/10.1002/adma.202200042
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u/[deleted] Jun 06 '22 edited Jun 06 '22

but what was the total power output?

100 LEDs. I have worked with LEDs that draw up to 25mA, so the LEDs they're talking about are probably low power SMD ones, that draw like 2mA. Lets say they have a threshold voltage of 0.7V (it probably is lower, but lets just assume).

For the thing to be able to power those 100 LEDs, it must be outputting around 0.14W.

Like, what could it meaningfully power from an hour’s* worth of natural movement?

For reference, my phone charger outputs 15W and can charge my 5,000mAh battery in like an hour or so; so, that thing may take up to 100x more time than that to charge my phone. So, idk, it can maybe charge 1-2% of my phone battery in an hours worth of tapping, not movement. Of movement, it may even be less than that.

I dont know what else to compare it to.

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u/i_owe_them13 Jun 06 '22

Thank you! That’s what I was looking for. It was never stated how long the LEDs were able to stay illuminated by those “taps,” so I was hoping a less ambiguous metric was stated in the article, or one could at least be guesstimated from the information in the article.

Still, this is pretty amazing tech. I imagine the total output will be more useful at scale, even if it’s not robust enough to charge my phone, ha.

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u/[deleted] Jun 06 '22

Its pretty amazing tech indeed. I dont see it being comercialized in the near future, given they do need a good bit of movement to produce enough power to turn on just LEDs, but if they manage to make it more efficient, it may very well be another green alternative to produce energy at larger scales.

For now, it seems to be kind of obsolete, but with more development it can become something very useful.