Your body, the battery: Powering gadgets from human “biofuel” | Hacker News Reader

Your body, the battery: Powering gadgets from human “biofuel”

arstechnica.com

45 pointscyang0817 comments

I'm surprised they don't mention methane. Given that a natural byproduct of e.coli is methane as it reduces organic waste in your intestine, a fuel cell which could transfer oxygen from the blood and methane from the bowel would potentially generate milliwatt or two. As I recall there was some work on a methane recapture facility for grazing animals as a way of powering remote monitoring as well. Easy to joke about too, "Honey, pull my finger, I need to charge my phone."

Messing with the gut is really dangerous, your probably far better off just harvesting some sugars from the blood stream than trying to use methane.

Messing with the blood is not danger-free either. Wrong blood-sugar levels or acidity, bloodclots, gas-bubbles...

Slightly off-topic, but i find impressive that with the same 2,500 calories needed to power daily my moderately used smartphone, my body can walk, go up the stairs, lift heavy objects, do math, laugh and think.

Way to go to match the efficiency of the human body.

I can't make sense of this statement in the article - it seems to be off by two orders of magnitude.

A typical smartphone battery (Xiaomi Mi4i) is specified at 3.12Ah @ 4.4V. Multiplying, we get an energy content of about 50 kilojoules, which is about 1/200th of the a typical daily human energy requirement (10MJ).

As snaily said above, your smartphone really doesn't need 2500kcal/day. I think what they were trying to say is that, given 100% perfect energy transfer, you'll be able to power your phone from your daily calories without missing much. As in, "this is so much, you can power a phone without realising something's missing".

Dietary calories are actually kilocalories. 2500 kcal is approximately 3kWh..enough to run a thousand phones for an hour.

What's impressive isn't the efficiency of the body's use of energy (electric motors are already pretty good) , but rather how efficiently it extracts and stores it.

If smartphones had our stomachs, we wouldn't need to charge them..just let throw a hamburger in there once a month.

Best diet ever. I wonder how many people would abuse this and crank everything up to 11 just to burn calories.

Assuming just for a second that they could do it relatively safely, why shouldn't they?

Possibly because they will figure out a way to bypass any safety requirements and maybe hurt themselves which usually happens with most technology. People will attempt to dive into rushing water when they lose their phones.

If they're going to hurt themselves voluntarily, I am of the opinion that we should let them

under the supervision of a qualified doctor and a bio-engineer, sure, go for it. I think the guy you replied to was talking about a more "hacker" approach. And keep in mind no hacker worth his salt has ever gotten where they have in life without frying a few circuits or crashing a server.

"If at first you don't succeed, then hacking your own organs and/or skydiving are probably not for you"

I'm assuming that if there's a safe way to do it, there's also an unsafe way to do it even further ("crank it up to 11"). I'm sure it would be a really strong temptation for a lot of people. That's what I was wondering about in the comment. But yeah if it's safe, I'd be all for it!

I would — that was my first thought.

I can't wait for this stuff to come out! It'll be so neat.

How can no one mention Matrix?

I've seen this documentary, comes in three parts, the fist one is great, the other two less so. I seem to recall a particularly vexing cave rave scene, which, to this day, makes no particular sense to me. As you were.

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