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Body Heat Energy Generation

CmdrTaco posted more than 4 years ago | from the i'm-sweating-right-now dept.

Power 214

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."

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I'd prefer a cock ring.$ (0, Troll)

Adolf Hitroll (562418) | more than 4 years ago | (#30535148)

nt

Re:I'd prefer a cock ring.$ (0)

Anonymous Coward | more than 4 years ago | (#30535270)

A fellow such as yourself should be able to find them at any supermarket in a box labelled "Cheerios".

Re:I'd prefer a cock ring.$ (1)

Adolf Hitroll (562418) | more than 4 years ago | (#30535390)

so trolls have no dick on your silly planet?
no wonder you're still a virgin, ac.

Re:I'd prefer a cock ring.$ (0)

Anonymous Coward | more than 4 years ago | (#30535676)

Where do they sell single Cheerios? As one will probably last him quite awhile.

Someone like him will probably have to slice one into two or three rings anyway, due to the comparative length of a Cheerio.

uh oh (0, Insightful)

Anonymous Coward | more than 4 years ago | (#30535152)

The matrix is coming......

Re:uh oh (-1, Troll)

Anonymous Coward | more than 4 years ago | (#30535176)

I'm cuming in your mother's mouth coppertop.

Re:uh oh (-1, Offtopic)

Anonymous Coward | more than 4 years ago | (#30535276)

that's what SHE said

heat can be used to power stuff (0)

Anonymous Coward | more than 4 years ago | (#30535164)

news at 11

Re:heat can be used to power stuff (1)

blai (1380673) | more than 4 years ago | (#30535882)

The news here is how small the heat gradient we're working with.

Truely Fremen fashion (2, Insightful)

gzipped_tar (1151931) | more than 4 years ago | (#30535170)

What's next? A body-movement powered (or better, heat & movement hybrid power), fully functional stillsuit?

Re:Truely Fremen fashion (0, Funny)

Anonymous Coward | more than 4 years ago | (#30535198)

You don't NEED a stillsuit to drink your own pee. Feel free.

Re:Truely Fremen fashion (2, Interesting)

Forge (2456) | more than 4 years ago | (#30535406)

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:Truely Fremen fashion (4, Funny)

camperdave (969942) | more than 4 years ago | (#30535986)

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.

Of course, the problems involved in acquiring and caring for a human sized hamster tend to outweigh the benefits.

There is no spoon. (1)

TravisHein (981987) | more than 4 years ago | (#30535188)

Great, now in the future when robots and machines rule the earth, they can use this to harvest energy from all of us, just like the Matrix.

Re:There is no spoon. (1)

sakdoctor (1087155) | more than 4 years ago | (#30535232)

Thanks to the laws of physics, they will only be micro-power overlords.
Though perhaps they won't need massive amounts of force to subdue humanity; from what I've seen, most people would choose the blue pill.

Re:There is no spoon. (1)

jggimi (1279324) | more than 4 years ago | (#30535506)

Or the woman in the red dress. :)

Blue Smarties. . . (4, Informative)

Fantastic Lad (198284) | more than 4 years ago | (#30535880)

Though perhaps they won't need massive amounts of force to subdue humanity; from what I've seen, most people would choose the blue pill.

I've long believed that the physical reality we live in, being entirely a product of energy and thus little more than an illusion, the idea of matter and as such is inherently linked to consciousness. . , that all things in our reality can be observed as and understood to be metaphors for systems and conflicts we are experiencing in our conscious awareness.

-You have to plug humans into the Matrix at the start of their lives when kids are most inquisitive. Red Smarties are the most popular color, and the battle over Blue Smarties rages on. . !

In 2006 it was announced that Nestlé [wikipedia.org] were removing all artificial colourings from Smarties in the UK, owing to consumer concerns over the effect of chemical dyes on children's health. Nestlé decided to replace all synthetic dyes with natural ones, but as they were unable to source a natural blue dye, the blue Smarties were removed from circulation, and white Smarties were introduced in their place. White Smarties were later removed from the range, and blue Smarties were re-introduced in the UK in February 2008, using a natural blue dye derived from the cyanobacteria spirulina.

Dieticians [...] said that the blue coloring was the one which was most likely to cause intolerance in kids. [medindia.net] "The thing about blue is there are no natural equivalents. All the others can be obtained from natural sources," said Linda Hodge, a dietitian. "I believe the Brilliant Blue causes the worst symptoms of chemical intolerances."

She added that when consumers are being tested for intolerances, the first color tried out is yellow. "When we are trying to determine if a person is sensitive to food coloring, we test them first on yellow. If there is no reaction we then use red, then blue. We don't start off with blue because it is a the strongest color and gives the worst reactions," she observed.

Humans naturally try to reject the Matrix. "Entire crops were lost."

Neat, huh?

-FL

Re:There is no spoon. (1)

iamapizza (1312801) | more than 4 years ago | (#30536146)

I think it's all a steaming pile of crap. Get it? waste. heat. Oh, I slay myself.

Screw that (3, Insightful)

elrous0 (869638) | more than 4 years ago | (#30535210)

You're wasting the real potential of this thing. I live in an area that gets hot as hell in the summer. If it really does get "uncomfortably cold," I'd pay good money for a whole suit made of the stuff.

Re:Screw that (1)

dintech (998802) | more than 4 years ago | (#30535950)

Good idea and hurry the hell up with that next shipment of Spice.

Re:Screw that (2, Informative)

Thelasko (1196535) | more than 4 years ago | (#30535966)

Unfortunately, the summary and the Physics Buzz article grossly misrepresent the research being done here. The device only becomes "uncomfortably cold" when ambient temperatures are below what are considered comfortable by most people. The AIP article also notes that it is unlikely that this device will ever be able to harvest enough energy to power current portable devices. They instead suggest that future devices be designed around the power output of this device.

Cold? (1)

Hatta (162192) | more than 4 years ago | (#30535220)

I don't understand how it can get cold. You can harvest energy from a temperature gradient, but once the headband is at ambient temperature, there's no more gradient. How does it get cold?

Re:Cold? (0)

Anonymous Coward | more than 4 years ago | (#30535240)

Do you normally harvest heat from dead bodies at nearly ambient temperature? If so, your ideas intrigue me and I wish to subscribe to your newsletter.

Re:Cold? (3, Insightful)

oodaloop (1229816) | more than 4 years ago | (#30535244)

It feels cold because it's sucking heat out and using it. So it's constantly leaching heat out. Hence it would feel cold. Simple, really.

Re:Cold? (1)

Thanshin (1188877) | more than 4 years ago | (#30535310)

It feels cold because it's sucking heat out and using it. So it's constantly leaching heat out. Hence it would feel cold. Simple, really.

Heat can't be turned directly into energy, only difference in heat.

Re:Cold? (3, Insightful)

Hatta (162192) | more than 4 years ago | (#30535512)

It's not sucking heat out, that would actually require extra energy input. It's not a pump, it's more like a water wheel.

But my question has been answered. It doesn't get below ambient temperature. We just don't feel ambient temperature as cold as it actually is, because air is a pretty good insulator.

Re:Cold? (1)

Thangodin (177516) | more than 4 years ago | (#30535718)

Yeah, I was wondering the same thing. Either the ambient temperature has to be pretty cool, or the thing has to be fitted with liquid coolant--which makes it essentially a battery. Leaving this out of the explanation makes all the claims pretty underwhelming.

Re:Cold? (0)

Anonymous Coward | more than 4 years ago | (#30535796)

It feels cold because it's sucking heat out and using it. So it's constantly leaching heat out. Hence it would feel cold. Simple, really.

Oh yeah, it's simple really. It literally have little suck things that suck out heat as a liquid. It's so intuitive and easy to understand. With air conditioning systems and fridges being such power hogs, one should wonder where didn't someone put heat suck things on a box to make an air conditioner that not only keeps your room cool, but powers your TV in the process!

Re:Cold? (1)

Thelasko (1196535) | more than 4 years ago | (#30535838)

It feels cold because it's sucking heat out and using it. So it's constantly leaching heat out. Hence it would feel cold. Simple, really.

From TFA:

at lower ambient temperatures, the heat flow rapidly exceeds the sensation of discomfort and the device turns into uncomfortably cold object. For example, at 19C, the TEG already produces 3.7 mW, but the sensation of cold becomes too annoying.

At 19C you would start to become uncomfortable whether you were wearing this device or not.

Re:Cold? (1, Informative)

Anonymous Coward | more than 4 years ago | (#30535258)

Compared to your body temp, ambient temperature is cold. Try putting a piece of ambient steel against your skin and tell me if it's cold.

Re:Cold? (1)

Thanshin (1188877) | more than 4 years ago | (#30535264)

If it gets as cold as the ambient, it's as unconfortable as not wearing anything on that clothing slot. Which, beyond the polar circle, for example, can be between "quite" and "fucking".

Re:Cold? (1)

Yamata no Orochi (1626135) | more than 4 years ago | (#30536106)

If it gets as cold as the ambient, it's as uncomfortable as not wearing anything on that clothing slot. Which, beyond the polar circle, for example, can be between "quite" and "fucking".

You play too many video games.

Re:Cold? (2, Insightful)

sakdoctor (1087155) | more than 4 years ago | (#30535286)

Those of us who descended from the mammalian evolutionary tree, keep our bodies warmer than ambient temperatures.

Re:Cold? (0)

Anonymous Coward | more than 4 years ago | (#30535292)

The only thing I can think of is that air is a pretty rotten conductor. So if you put your skin up against a big heat sink at the same temperature as the air it will "feel" colder because it is more effective at removing the heat from where it contacts your skin.

NASA has used these things for 50+ years except on a hunk of plutonium that is kept warm by naturally decaying. They are called RTG's. The temperature gradient of a person to their surroundings is very small so this is of little use.

Re:Cold? (2, Informative)

confused one (671304) | more than 4 years ago | (#30535392)

It's better at conducting heat away from your skin than air; and, because it's extracting energy and using a small radiator as a heat sink, it remains colder than the skin. It only feels cold. It would never actually reach ambient because your body is keeping it above ambient, with the asumption that "ambient" is well below body temperature. From the article:

"At 22C, it produces about 30W/cm2, i.e., close to the theoretical limit of power generation on people at this temperature in a compact device. There is, however, a drawback of such high power generation: at lower ambient temperatures, the heat flow rapidly exceeds the sensation of discomfort and the device turns into uncomfortably cold object. For example, at 19C, the TEG already produces 3.7 mW, but the sensation of cold becomes too annoying. "

Re:Cold? (2, Funny)

vegiVamp (518171) | more than 4 years ago | (#30535662)

So in warm countries (or during a heat wave), when ambient is *above* body temperature, do yo wear it inside-out ?

Re:Cold? (1)

confused one (671304) | more than 4 years ago | (#30535738)

That might work with some modification but you could see how that might not be a good idea (hyperthermia bad). They did mention an increase in power production when the wearer moves from outdoors to an air conditioned indoor environment.

Re:Cold? (1)

TummyX (84871) | more than 4 years ago | (#30535422)

If it is constantly sucking heat energy away from you then it will feel cold. Your body doesn't feel cold from the cold but rather from change in temperature. Metal at ambient temperature feels cold because it conducts the heat away from your body more efficiently than wood for example. This device must be efficient at sucking heat away from your body in order to generate electricity.

Re:Cold? (5, Informative)

Issarlk (1429361) | more than 4 years ago | (#30535466)

The headband is at ambiant temperature, but your body is much warmer. Heat flow from your body to the headband and leaves a cold sensation on your skin. The material of the headband applied to the body is probably a good conductor of heat ; it's like with a piece of metal that feels cold to the touch and a piece of wood that doesn't while both are at room temperature.

Re:Cold? (1)

lazn (202878) | more than 4 years ago | (#30535806)

How about those who live in a desert where the ambient temperature is HIGHER than body temp?

Re:Cold? (0)

Anonymous Coward | more than 4 years ago | (#30535984)

Turn the headband inside out. Simple.

Re:Cold? (1)

Rhacman (1528815) | more than 4 years ago | (#30535990)

As long as it isn't the same as your body temperature you would still have a thermal gradient to work with. Your body would be cooling itself by sweating and the device would be harvesting the heat energy that is flowing into your head through the headband rather than the other way around. http://en.wikipedia.org/wiki/Thermopile [wikipedia.org]

Re:Cold? (1)

Thelasko (1196535) | more than 4 years ago | (#30535874)

TFA states that the headband only becomes uncomfortable below 19 degrees Celsius, which is below common room temperatures. One could argue that a human would be uncomfortable below room temperature wheather they are wearing this device or not.

However, you are correct. Humans are not good at judging temperature. We are good at judging heat transfer, which is why metal objects seem colder at the same temperature as nonmetals.

Re:Cold? (1)

Mr. Slippery (47854) | more than 4 years ago | (#30535538)

You can harvest energy from a temperature gradient, but once the headband is at ambient temperature, there's no more gradient.

Unless the ambient temperature is equal to your skin temperature, there's a gradient.

Or are you confused by the idea that something at ambient temperature can feel uncomfortably cold? A surface at 19 C (66 F) right against your forehead, actively conducting away heat, is a different sensation than air at the same temperature. It's not just the temperature, but the thermal conductivity For example, air at that temperature is fairly comfortable (little chilly for my taste), but water at the same temperature can (with long exposure) cause mild hypothermia.

Re:Cold? (1)

carvalhao (774969) | more than 4 years ago | (#30535756)

Although I can't name it, there was a movie in the 80's about a building that recycled human body heat for energy... until the computer went awry and started killing everyone for their body heat.

Re:Cold? (0)

Anonymous Coward | more than 4 years ago | (#30536012)

Although I can't name it, there was a movie in the 80's about a building that recycled human body heat for energy... until the computer went awry and started killing everyone for their body heat.

Illogical computer ... killing a human is certain way to halt the heating process!

Re:Cold? (1)

mcgrew (92797) | more than 4 years ago | (#30535938)

Seventy degree air (21.11 C) is comfortable. Jump into a pool of eighty degree (26.66 C) water and it feels like it's freezing. Water that comes from your cold water tap in the summer is close to the ambient temperature, but soak a rag in it and wrap it around your neck and it will cool you off quickly (until the water in the rag raises its temperature to match yours).

Re:Cold? (1)

selven (1556643) | more than 4 years ago | (#30536128)

As you said, the headband approaches ambient temperature. In the winter, ambient temperature is -4, ie. cold.

Ah, the joys of biofuels (1)

bradm (27075) | more than 4 years ago | (#30535228)

I suppose now we'll all wear parkas and cram energy bars during our kernel compiles?

Anyone know the cost per KWH of corn syrup?

A personal airconditioner? (2, Interesting)

rolfwind (528248) | more than 4 years ago | (#30535252)

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:A personal airconditioner? (1)

DallasMay (1330587) | more than 4 years ago | (#30535444)

Probably wouldn't work in Iraq. If this does work, it would pull heat from you and into the ambient environment. That means that there has to be a temperature drop between you and the air for it to work.

Re:A personal airconditioner? (3, Interesting)

dvoecks (1000574) | more than 4 years ago | (#30535470)

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? (2, Funny)

Adhemar82 (958364) | more than 4 years ago | (#30535486)

Time to invade Siberia!

Re:A personal airconditioner? (1)

vegiVamp (518171) | more than 4 years ago | (#30535744)

You'd still have a temperature gradient, just the other way round.

Re:A personal airconditioner? (0)

Anonymous Coward | more than 4 years ago | (#30535832)

So the ambient heat would flow ... into my body? Methinks this is not a good idea.

Re:A personal airconditioner? (1)

Jake Griffin (1153451) | more than 4 years ago | (#30535890)

Which means it would feel uncomfortably hot rather than uncomfortably cold. Kinda defeats the purpose of cooling off the soldiers.

Re:A personal airconditioner? (1)

Jake Griffin (1153451) | more than 4 years ago | (#30535904)

Sorry for the double post, but I had another thought. I honestly don't believe that this would work as well with the hotter ambient temperature because of how much better our skin is as a conductor as opposed to the air... I could be mistaken however, as I'm not totally sure how this works.

Re:A personal airconditioner? (1)

mcgrew (92797) | more than 4 years ago | (#30536016)

Sure, it would work well at room-temperature, but who needs cooling at room-temp?

If you live in a dry climate, over a hundred degrees F isn't bad unless you're in the sun. In a humid climate eighty five is uncomfortably hot, as your sweat won't evaporate as well. It probably wouldn't work well in Arizona in the summer, but it would be great in a place like St Louis or (moreso) Thailand.

It would have worked well in Viet Nam, probably wouldn't work at all in Iraq.

Re:A personal airconditioner? (3, Interesting)

Thelasko (1196535) | more than 4 years ago | (#30535616)

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!

not usually how it works (5, Informative)

v1 (525388) | more than 4 years ago | (#30535256)

As a side benefit, the power sources help cool you down

Typically if you take something that's trying to dump waste heat, and install something that recovers power from that heat, it creates an insulating effect, reducing the cooling the object was receiving. Heat can't be turned directly into energy, only difference in heat. Adding a heat reclamation system doesn't help cool something down because the power it's getting is from the temperature difference, not the heat itself. Instead it takes power from the temperature gradient, and as such reduces the temperature gradient, thus reducing cooling efficiency.

Re:not usually how it works (2, Informative)

maxwell demon (590494) | more than 4 years ago | (#30535446)

Well, unless they built a perpetual motion machine of the second kind. :-)

But actually, it may be due to the fact that normally you don't really feel the real temperature, but when it's cold, the temperature of the air directly at your skin is still higher than the surrounding air (unless there is wind, which is why you feel cold faster when there's wind). If this device has better heat transport to the surrounding air (e.g. because the surface to air is larger than the surface to you skin), you may feel colder that normally.

Re:not usually how it works (1)

maxume (22995) | more than 4 years ago | (#30535452)

They are also attaching a big radiator to people's foreheads.

And the actual paper doesn't really talk about a cooling effect, it simply states that the contact with the device becomes uncomfortable in ambient temperatures much below 22 Celsius.

Re:not usually how it works (1)

jollyreaper (513215) | more than 4 years ago | (#30535686)

Typically if you take something that's trying to dump waste heat, and install something that recovers power from that heat, it creates an insulating effect, reducing the cooling the object was receiving. Heat can't be turned directly into energy, only difference in heat. Adding a heat reclamation system doesn't help cool something down because the power it's getting is from the temperature difference, not the heat itself. Instead it takes power from the temperature gradient, and as such reduces the temperature gradient, thus reducing cooling efficiency.

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.

Re:not usually how it works (2, Interesting)

vlm (69642) | more than 4 years ago | (#30535940)

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:not usually how it works (2, Funny)

dintech (998802) | more than 4 years ago | (#30536002)

Drinking your own pee has always been free.

Re:not usually how it works (4, Informative)

JerryLove (1158461) | more than 4 years ago | (#30535698)

Yes. Power is generated when heat is moved from an area of high concentration (your head) to an area of low concentration (the air).

If the device facilitates that transfer in order to get more energy from it; then it would indeed cool you down. It requires only tha the headband be more effective at radiating heat than your skin is.

Serious fashion (0)

Anonymous Coward | more than 4 years ago | (#30535760)

Yes, I had that issue with the article^Wsummary as well, also, aren't those things fashionable as hell? Must just be the 'cool' of the fashion helping to keep the body heat down.

Re:not usually how it works (0)

Anonymous Coward | more than 4 years ago | (#30535860)

It works just fine, as long as the heatsink on the 'cool' side of the system is significantly better than it would be otherwise. But, you are always going to have worse heat transfer with a power generator in the middle than you would if you simply attached the same heatsink to the heat source directly.

/po

Re:not usually how it works (1)

Shotgun (30919) | more than 4 years ago | (#30535978)

As a side benefit, the power sources help cool you down

Typically if you take something that's trying to dump waste heat, and install something that recovers power from that heat, it creates an insulating effect, reducing the cooling the object was receiving.

Unless, the device dumping the waste heat originally had a very inefficient path for dumping the heat. You can come in, install a more efficient "heat dumping" path and then bleed off some of the difference in the form of useful energy.

Bullshit (-1)

HEbGb (6544) | more than 4 years ago | (#30535316)

Causing any part of the system to cool below ambient requires the net consumption of energy.

Sure, you can harvest a bit of energy from a temperature differential, but you will NOT create "cold". Quite the opposite. These attempts of microenergy harvesting from body heat have been around for decades, and are nothing new.

These guys are either liars, or don't know what the hell they are doing.

Re:Bullshit (4, Informative)

jdunn14 (455930) | more than 4 years ago | (#30535434)

I was going to just mod you down, but the summary at least never said anything about lowering any part of the device below ambient. It said that the headband will "feel cold". Touch a piece of wood at room temperature. It will sometimes "feel" warm. Do the same thing with a piece of steel. It will "feel" cold. This is true even if both are at the exact same temperature. Heat conduction [wikipedia.org]

The kids section of my local science museum even has hand-shaped pieces of different materials to demonstrate the effect.

Re:Bullshit (0)

Anonymous Coward | more than 4 years ago | (#30535500)

Thank you, jdunn. I wanted to make a reply just like this.

Re:Bullshit (-1, Offtopic)

Anonymous Coward | more than 4 years ago | (#30535852)

I was going to just mod you down...

and then you woke up and realized that is NOT what the modding system is for and instead you posted to discuss your disagreement.

More people on slashdot should try this approach maybe.

All I have to say... (1)

ultraexactzz (546422) | more than 4 years ago | (#30535330)

Welcome to the desert of the real...

Free Energy? (2, Insightful)

lobiusmoop (305328) | more than 4 years ago | (#30535338)

FTFA:
"Imagine portable electronics that run on a free, reliable energy source."

Um, I'm already practically there. I can get a KWh out of the wall for 5p (10c), charge up an iPhone from dead to full for a quarter (5KWh battery capacity there) and can get as many cheap chargers as I like. On my list of concerns right now, body-heat chargers are pretty far down.

Re:Free Energy? (1)

Shikaku (1129753) | more than 4 years ago | (#30535386)

Brown energy is the new green! The brown energy is the product of human heat generation. This brown energy can be used to fertilize crops.

Re:Free Energy? (1)

Hoi Polloi (522990) | more than 4 years ago | (#30535530)

Or it can be used to power the Matrix for our computer overlords.

Re:Free Energy? (3, Insightful)

Anonymous Coward | more than 4 years ago | (#30535490)

http://en.wikipedia.org/wiki/Battery_(electricity)#Rechargeable_battery_chemistries [wikipedia.org]

I'd love to know where you get 5 kWh from an iPhone battery. Li-Ion batteries have an energy density of 128 Wh/kg, so your iPhone battery must weigh 39 kg.

Granted, a 5 kWh Li-Ion battery will cost a fortune, so for something of that capacity, you're more likely to use a lead-acid battery of car/alarm/emergency light fame. That battery would weigh 129 kg. My brother-in-law has an iPhone; I'll ask him if it came with a dolly for the battery.

Now, it would make more sense if that was a 5 Wh battery; then we're talking about 39 grams, which is probably a bit easier to carry around. And your charging cost is down to 0.005p, but will likely be a good deal higher due to energy loss.

Re:Free Energy? (1)

lobiusmoop (305328) | more than 4 years ago | (#30535618)

LOL, sorry, my bad. Need more coffee...

Re:Free Energy? (1)

jeffb (2.718) (1189693) | more than 4 years ago | (#30535516)

Um, I'm already practically there. I can get a KWh out of the wall for 5p (10c), charge up an iPhone from dead to full for a quarter (5KWh battery capacity there) and can get as many cheap chargers as I like.

Um, I think you're off by at least three orders of magnitude there.

On my list of concerns right now, body-heat chargers are pretty far down.

Well, as long as you spend your whole life no more than a few hours away from a power outlet, that makes sense.

I'm still not buying the body-heat solution, though. Let's get something that runs off blood sugar instead.

Re:Free Energy? (1)

oodaloop (1229816) | more than 4 years ago | (#30535562)

And once your phone never needs to be re-charged again, you'll wonder how you ever lived with something as archaic as plugging it in when it was low. Also, it may be cheap to you, but that doesn't mean it's cheap to, say, the environment. Having the population of the UK charge their devices off of coal-fired power plants instead of human generated heat isn't exactly optimal.

Re:Free Energy? (1)

vlm (69642) | more than 4 years ago | (#30535820)

Also, it may be cheap to you, but that doesn't mean it's cheap to, say, the environment. Having the population of the UK charge their devices off of coal-fired power plants instead of human generated heat isn't exactly optimal.

Its a "well known fact" that it takes about 10 kcal of petroleum products to make about 1 kcal of food, on average. Natgas turned into fertilizer, diesel powered everything, processing plants, shipping, etc. And the efficiency of the conversion device is probably not too good. And the efficiency of the human body at turning food into heat is not too good.

So, ignoring capital costs, unless the UK power system is substantially below 1% efficient, you'll end up environmentally ahead using wall outlet power. On the other hand, environmentalism has replaced the old catholic church system of feeling guilty and being inconvenienced, and this tech might work for that, in which case it could be extremely "environmentally optimal" in a sociological sense.

Re:Free Energy? (1)

Skater (41976) | more than 4 years ago | (#30535908)

Flaw in your argument: people already exist and eat that food anyway. This idea is to take heat that already exists and is being wasted (sometimes) and make it do useful work for us.

Re:Free Energy? (1)

mdarksbane (587589) | more than 4 years ago | (#30536118)

Of course, if this device is pulling heat faster than the surrounding air, you will need to burn more calories than before to continue powering it.

If you're in a situation where your body is already dumping heat as fast as it can (ie, you're sweating) it's recapturing waste energy. If you're in a cooler environment, though, the heat will need to be replenished by burning calories to maintain temperature. Users would either lose weight or eat more.

Of course, all of this is a fair amount of bullshit since the effect of any such device is so small as to be completely pointless in environmental terms.

Re:Free Energy? (1)

mcgrew (92797) | more than 4 years ago | (#30536130)

It's only "free" in the sense that an empty potato chip bag is free. You paid for the bag when you bought the chips, and you also paid for the waste heat when you bought the chips.

underpants (0)

Anonymous Coward | more than 4 years ago | (#30535400)

I have always wanted air conditioned underpants. My dream just might come true!

Re:underpants (1)

Shotgun (30919) | more than 4 years ago | (#30536024)

Yeah, and the underpants will be good for playing contact sports also, because they will be made of metal. Give new meaning to the "Under Armour" brand of sportswear.

Wait, What happens if your head gets too hot? (2, Funny)

Anonymous Coward | more than 4 years ago | (#30535402)

If your head gets too hot with the hat on, simply put another heat absorber around your hat. If your head gets too cold again, put on another hat.

Canada (3, Funny)

Galestar (1473827) | more than 4 years ago | (#30535482)

I live in Canada... I need all of my body heat as it is.

They've come a long way! (1)

Lord Lode (1290856) | more than 4 years ago | (#30535526)

I was a student at this university, some 5 years ago all students who visited IMEC had to do an experiment for them, namely wear a watch with this technology and then it'd generate a few microwatts out of the difference between the outside and body temperature. They even gave a funny speech related to The Matrix before the experiment. It seems they've improved a lot in the meantime, though it's a shame the article doesn't mention how much power it currently generates.

Re:They've come a long way! (1)

confused one (671304) | more than 4 years ago | (#30536054)

Ummm, yeah it did. The pulseox meter required 62 uW. A watch sized device could theoretically generate between 100 and 600 uW per the article. The headband was generating 30uW/cm^2 for 3.7mW at 19C during their testing. The shirt required 0.5mW, was generating 0.8 to 5.5mW. All depending on the users activity level and the ambient conditions.

Overrated (1)

ooctav (1684044) | more than 4 years ago | (#30535534)

Hamsters are overrated.

Wristband blood oxygen sensor? (1)

wcrowe (94389) | more than 4 years ago | (#30535548)

While that's pretty interesting, I'd like to see a non-invasive wristband blood glucose sensor. Now that would be something.

Re:Wristband blood oxygen sensor? (2, Informative)

quercus.aeternam (1174283) | more than 4 years ago | (#30535924)

If you need continuous monitoring, you probably need more accuracy than non-invasive means will get you.

As of 2003 (when I spent a summer internship at Sensys Medical), the best non-invasive method (near-infrared spectroscopy) would get you within 20% of the actual value - and that's with an initial blood sample for calibration. IIRC, most consumer devices are accurate to 10-15%, with cheaper clinical devices being accurate to 5%.

Knowing the hardware necessary for even that degree of accuracy as well as the difficulties we had getting a clean signal while trying to shrink stuff down to shoebox size, there's no way that this would work - not with IR, anyway.

The accuracy should have improved since then, and these numbers are purely from memory. That said, you are right. That would be something - but given accuracy and demand, don't plan on it in your lifetime.

Just call me... (0)

Anonymous Coward | more than 4 years ago | (#30535642)

copper top

Not a heat pump! (1)

burisch_research (1095299) | more than 4 years ago | (#30535728)

Any heat harvesting system relies on a temperature differential - in this case, the temperature difference between your body and the air. If the device were a perfect conductor of heat, a) it would generate no power at all (because there is no temperature differential) and b) this would be pretty much identical to not wearing the device at all.

In reality, all such devices must be imperfect heat conductors (i.e. they insulate heat), and as such your skin temperature will always be higher than it would be if you were not wearing one of these. (obviously this ignores the comparison between how efficiently your skin dissipates heat, vs how quickly the 'cold' end of the thermopile does.)

Listen to me coppertop (0)

Anonymous Coward | more than 4 years ago | (#30535758)

THEY'RE COMING!!!!

It has begun (1)

quatin (1589389) | more than 4 years ago | (#30535804)

Morpheus: What is the Matrix? Control. The Matrix is a computer-generated dream world built to keep us under control in order to change a human being into this. [holds up a Duracell battery]

But in all seriousness. There were previous articles about physical implants into the body that run on body heat. The idea isn't so new, this is just less invasive.

Internal use? (1)

srothroc (733160) | more than 4 years ago | (#30535894)

I'd really be interested in seeing if this could safely be used inside the body somehow. You could use it to power pacemakers. More relevant to my own interests, it could possibly power an internal assembly for a cochlear implant processor. It would be nice to get rid of all of the external bits so I could run, jump, swim, and wear hats normally.

Re:Internal use? (1)

confused one (671304) | more than 4 years ago | (#30536102)

You have to have a heat sink as well as a source. Some component would have to remain outside to act as a radiator.
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