Body Heat Energy Generation

BuzzSkyline writes "Researchers in Belgium have developed devices to harvest the waste heat our bodies throw off in order to convert it to electricity to run devices such as a wristband blood oxygen sensor and an electrocardiogram shirt. As a side benefit, the power sources help cool you down and keep you looking cool, all while running sundry micropower devices. In fact, the researchers mention that the energy harvesting head band works so well that it can get uncomfortably cold. In that case, they say, 'This problem is solved in exactly the same way as someone solves it on the body level in cold weather: a headgear should be worn on top of the system to limit the heat flow and make it comfortable.' But it would be such a shame to cover up the golden heat-harvesting headband with a hat."

A personal airconditioner?

[rolfwind]

If this is true:

In fact, the researchers mention that the energy harvesting head band works so well that it can get uncomfortably cold.

Wouldn't it be extremely marketable? Especially for the military with troops in hot places and with bulky body armor and probably all types of personal electronic equipment to keep charged?

Re:Truely Fremen fashion

[Forge]

You do if you want to drink the water expelled in your pee and sweat without any of those pesky toxins.

As for me, electricity costs are getting so high that a human sized hamster wheel attached to a basic generator coil looks really attractive right now. Additional benefits like exercise and looking cool on that thing should clinch the deal.

Re:A personal airconditioner?

[dvoecks]

That only works if the air temp is lower than 98.6. This sort of thing works by harnessing the difference in energy between the "hot" side and the "cold" side. Sure, it would work well at room-temperature, but who needs cooling at room-temp? About the only time you really need cooling when the air is significantly below normal body temperature outside is when you've got a fever, or are heavily exerting yourself. I definitely could get behind a headband that powers an mp3 player when I'm on a jog. It could have military applications, but it would be fairly limited. When it's 120 degrees in Iraq, this thing wouldn't work even if the soldier was running a marathon while dragging a broken down Humvee.

Re:A personal airconditioner?

[Thelasko]

Wouldn't it be extremely marketable? Especially for the military with troops in hot places and with bulky body armor and probably all types of personal electronic equipment to keep charged?

This also defies the laws of thermodynamics. Allow me to explain:

1. In Iraq, the surroundings are hotter than the human body. Therefore, it is impossible to harvest energy from human waste heat because heat is flowing to the human, not away from it.

2. The temperature gradient between a humans body and it's surroundings is not large enough to generate significant amounts of electricity. If it was, internal combustion engines would be a hell of a lot more efficient than they are today.

3. If the temperature gradient between a human body and it's surroundings were large enough to generate significant amounts of electricity, you might want that energy to keep warm!

Re:not usually how it works

[vlm]

This would be the reason why fremen stilsuits would be impossible, right? Even as a kid it struck me that someone was trying to have a free lunch.

The part that kills the stillsuit is there is an inherent minimum energy requirement to separate drinkable water from uh, bodily output, and there is also an inherent minimum energy requirement to condense water out of the air. Unfortunately, to generate that energy, the human body requires MORE water than would be produced by either process... Healthy human kidneys already do a pretty near optimal job of "recycling water".

Human powered camping filters only work because only a small fraction of the water is filtered, most bypasses into the waste outlet. Getting "all the H2O" would be way too hard. Hence the lack of commercially available human powered distillation apparatus. As for condensation, human powered bicycle air conditioners are not commercially viable, nor are human powered dehumidifiers... The navy would probably find a human powered exercisebike/dehumidifier to be useful, but it just doesn't work, you'll exhale/excrete more water than you could realistically condense.

This might make a weird mythbusters episode... can someone boil away a quart of water using an exercise bike hooked up to a generator without eating/drinking/sweating/excreting more than a quart of water? Answer appears to not only be "no" for boiling, but "no" for condensing too.

Re:Blue Smarties. . .

[camperdave]

Back in the 1960s, or perhaps the 1970s, before the "When you eat your Smarties, do you eat the red ones last?" campaign, Smarties were marketed with a song that included the line: "You'll see red, two shades of brown, but you'll never, ever, ever see blue". To this day, I feel betrayed every time I eat a blue Smartie.

Re:Blue Smarties. . .

[plasticsquirrel]

You are reinventing Buddhism, actually, which is mostly what the Matrix copies as well. The Buddha taught 2500 years ago that you don't have a body, the entire world is an illusion, and that mind is the only reality that human beings have ever experienced, or could even hypothetically ever experience. That all reality is observable through eight consciousnesses, some of which are associated with sense organs, and others which are more fundamental. There is a complete model of the mind all of its faculties, including the conception of thoughts. At the most fundamental level is a consciousness that is the complete non-duality of mind and matter.

If you want the details, the consciousness-only school developed them in India and then in China. However, most academics cannot understand the texts because they are heavily dependent on logic, technical terminology, and a model of the mind based on empirical observation of thoughts and phenomena in meditation. However, if anyone is interested, the basic text is quite short and is called the Sandhirnirmocana Sutra [wikipedia.org]. However, the most technical text in English, is the book written by the Chinese master Xuanzang Treatise on the Perfection of Consciousness-only [wikipedia.org]. Even for Lisp or Haskell-breathing intellectual programmers, these texts should prove quite challenging. And I fear westerners who pride themselves on their understanding of western philosophy would have no chance at all. There are extremely few people who read and understand this material, sadly.