A Thermoelectric Bracelet To Maintain a Comfortable Body Temperature

rtoz writes "Heating or cooling certain parts of your body — such as applying a warm towel to your forehead if you feel chilly — can help maintain your perceived thermal comfort. Using that concept, four MIT engineering students developed a thermoelectric bracelet that monitors air and skin temperature, and sends tailored pulses of hot or cold waveforms to the wrist to help maintain thermal comfort. The product is now a working prototype. And although people would use the device for personal comfort, the team says the ultimate aim is to reduce the energy consumption of buildings, by cooling and heating the individual — not the building. The team estimates that if the device stops one building from adjusting its temperature by even just 1 degree Celsius, it will save roughly 100 kilowatt-hours per month."

Comments

What about the humidity?

[Bill_the_Engineer]

Personal comfort involves more than just temperature.

Re:What about the humidity?

[MightyYar]

And 1 degree C is pretty cold... ~

Re:What about the humidity?

[MightyYar]

At my office, we are all required to inhale the office air, but exhale through little snorkels placed throughout the office which exhaust to the outside.

Re:What about the humidity?

[fuzzyfuzzyfungus]

A man's body is his own. His water belongs to the corporation.

Re:What about the humidity?

[chuckinator]

Yes, I wear my owl costume to them.

Sold!

[i kan reed]

Give one to me to keep cool, one to my girlfriend to keep warm, and we'll set the AC in the middle.

Re:Sold!

[Penguinisto]

Wait until she hits menopause... then you'll have to swap out that AC unit for a ginormous pile of dry ice.

Re:Sold!

[icebike]

Well, it actually is the same amount of energy transfer, its just that our cooling systems aren't as efficient as our heating systems.

Waveforms?

[fiannaFailMan]

Quoth TFA:

sends tailored pulses of hot or cold waveforms to the wrist to help maintain thermal comfort

"Waveforms?" What does that mean? Does it work by convection, conduction, radiation or what?

Personally I like the little space heater I keep under my desk. Makes it nice and cozy in winter. Much nicer than wrapping up with more layers.

Re:Waveforms?

[RealGene]

Thermoelectric coolers are typically controlled with PWM, to adjust their temperature. The polarity determines which direction the heat is pumped, the duty cycle of the PWM determines how much.

Re:Waveforms?

[icebike]

Once your follow the link from the self promoting blog to the actual article from MIT you find this

Over the course of developing its technology, the Wristify team made a key discovery: Human skin is very sensitive to minute, rapid changes in temperature, which affect the whole body. They found they needed to heat or cool any body part (in their case, the wrist) at a rate of at least 0.1 C per second in order to make the entire body, overall, feel several degrees warmer or colder.

After 15 prototypes, the team landed on its final product, which resembles a wristwatch and can be powered, for up to eight hours, by a lithium polymer battery. This prototype demonstrated a rate of change of up to 0.4 C per second.

The “watch” part of the prototype actually consists of the team’s custom copper-alloy-based heat sink (a component that lowers a device’s temperature by dissipating heat). Attached is an automated control system that manages the intensity and duration of the thermal pulses delivered to the heat sink. Integrated thermometers also measure external and body temperature to adjust accordingly.

Its clear from the article that there is no actual heating of the body involved. Their system does not have enough power to heat 150 pounds of (essentially) water even one degree in the time period mentioned, let alone maintain any elevated temperature over 8 hours.

They are simply tricking the body into thinking it is warm enough or cool enough so that you don't FEEL cold / hot. You still actually ARE too cold or too hot.

This sounds interesting but I wonder just how safe it is to trick the body's thermal regulation its cool enough such that it no longer pays attention to the fact that it might be running dangerously close to heat induced stroke? Or trick it into thinking its cold, so it ramps up the metabolism.

In fact this might be a more useful as w weight loss device than an energy saving device.
But I'm still not convinced we should let engineers start micromanaging bodily functions, when all they are worried about is the device and the energy consumption.

Technology to do the same thing was invented a LONG time ago. Its called a sweater.

Even cheaper is a simple cap. Put it on, and you reduce heat loss through your head sufficiently enough to actually warm your entire body. Take it off and the reverse happens. The cap will last for years with no need for environment polluting batteries, and never has to be plugged in or recharged.

Sounds dangerous

[punkr0x]

Isn't this basically tricking your body into thinking you're hotter or cooler than you really are? It might work temporarily but wearing this thing all day, every day sounds like it could mess up your body's ability to regulate your temperature.

Re:Sounds dangerous

[MightyYar]

You are supposed to take some ecstasy to balance things out. They have a pacifier version, too.

Re:Sounds dangerous

[unimind]

Actually, there have been some studies indicating placebos work regardless of whether the person knows it's a placebo.

Re:that powersaving claim might want to come

[jcochran]

Does it really cool you or give you just a cool feeling for a small while on your wrist?

Neither, it instead tricks your body into thinking the overall temperature is comfortable.

Heat allergies

[LongearedBat]

A few years ago my gf got an infection that now causes her to get rashes whenever she's warm, and being hot makes her skin terribly itchy. (Please don't bother with sordid jokes here. They're too easy, I'm tired and I'm actually being serious.) So far she's had to resort to taking antihistamines almost daily, and she's likely going to have to do that for the rest of her life.

This bracelet doesn't actually cover the body, so it's not actually making the skin cool. And I don't understand what the mean by waveforms across the skin. Does that mean it's telling the skin that it's cool/warm even when it's not?

So I'm wondering, could this be something to help her feel cool, and thereby less itchy, especially during summer?

Clothes?

[bananaquackmoo]

Am I missing something? Isn't this the exact same thing as putting on or taking off clothes?

Free alternative

[pla]

How about just letting most of us work from home, and only maintaining enough office space to host a handful of meeting/collaboration rooms? Bam, your whole "office building" just reduced to a 2nd story loft.

But hey, sure, let's instead try playing games with peoples' heads rather than address the real problem. And then the PHBs can ask themselves why the electric bill has actually gone up, when everyone starts keeping an electric space heater under their desk.

Re:that powersaving claim might want to come

[icebike]

but I could take drugs for that.

Sure, I would pass out once the body got too warm and I had tricked my sweat glands to not work to keep me cool, so it would be rather pointless and maybe horrifying... which gets us to that the bracelet would have to either do that(block sweating) or not really work at all then.

Exactly. Our use a cap, or a sweater, or thinner clothing in hot weather.

Letting engineers regulate the human body so that the building can be run on less energy is the perfect definition of ASS BACKWARDS.

MIT should grow a Medical school instead of leaching off of Harvard. Perhaps then they might actually understand what they are messing with and perhaps grow to have a concept of ethics as well.

Re:that powersaving claim might want to come

[icebike]

The real article is here: http://web.mit.edu/newsoffice/2013/madmec-design-competition-1017.html

(Damn slashdot editors allowing blog hyping instead of linking to the actual sources!!!)

Close reading of that indicates this is just a huge trick played on the body's temperature regulation system.
There is no actual heating or cooling of the body. Its probably dangerous at some level, and the body would
also probably "learn" to ignore it.

It's more of a technique than technology.

[denzacar]

Technology to do the same thing was invented a LONG time ago. Its called a sweater.

It's keeping one foot out from under the covers.