"MIT Wristband Could Make AC Obsolete"

[TopWargamer]

http://www.wired.com/design/2013/10/an-ingenious-wristband-that-keeps-your-body-at-the-perfect-temperature-no-ac-required/

 

 

Wristify, as they call their device, is a thermoelectric bracelet that regulates the temperature of the person wearing it by subjecting their skin to alternating pulses of hot or cold, depending on what’s needed. The prototype recently won first place at MIT’s Making and Designing Materials Engineering Competition, netting the group a $10,000 prize, which they’ll use to continue its development. It’s a promising start to a clever approach that could help alleviate a serious energy crisis. But as Sam Shames, the MIT senior who helped invent the technology, explains, the team was motivated by a more prosaic problem: keeping everyone happy in a room where no one can agree where to set the thermostat.

 

It looks kind of stupid, but you would be wearing it around the house anyways...most of the time. It is definitely a neat invention though, and if the price is right, I would definitely buy one. Hopefully they make it look a bit less like a...well...computer heatsink. 

[everything count to life]

This MIT Wristband is shaping up to be a very good product, that might be worth buying.

[Vitalius]

It looks kind of stupid, but you would be wearing it around the house anyways...most of the time. It is definitely a neat invention though, and if the price is right, I would definitely buy one. Hopefully they make it look a bit less like a...well...computer heatsink. 

It will be developed further. That's a prototype.

They won $10,000 in the MIT competition to work on it more, as it says in your quote. He said he believes the same level of performance can be done in half the area. Which will be nice.

[ionbasa]

I would like to see this technology implemented in smart watches, the basic principle is used through a thermocouple to produce energy. http://en.wikipedia.org/wiki/Thermoelectric_generator

So we could have smart watches that never need to be plugged in, the downside is that the tech isn't very efficient, but I am sure optimizations will follow suit.

 

Edit: Also see: http://en.wikipedia.org/wiki/Thermoelectric_effect

[Canoas]

I would like to see this technology implemented in smart watches, the basic principle is used through a thermocouple to produce energy. http://en.wikipedia.org/wiki/Thermoelectric_generator

So we could have smart watches that never need to be plugged in, the downside is that the tech isn't very efficient, but I am sure optimizations will follow suit.

 

Edit: Also see: http://en.wikipedia.org/wiki/Thermoelectric_effect

It's AC as in Air Conditioners, not Alternating Current

[ionbasa]

It's AC as in Air Conditioners, not Alternating Current

It still works the same way though; just backwards. The wristband can heat up if energy is applied to it, or can produce electricity if energy is absorbed instead of emitted. Also these devices run off of DC, and nowhere in my statement did I mention Alternating Current.

 

I just gave a suggestion on where this technology can also be used.

[Canoas]

It still works the same way though; just backwards. The wristband can heat up if energy is applied to it, or can produce electricity if energy is absorbed instead of emitted. Also these devices run off of DC, and nowhere in my statement did I mention Alternating Current.

 

I just gave a suggestion on where this technology can also be used.

You talked as if the device would replace Alternating Current, not Air Conditioner. And no, it can't work "backwards", that makes no sense whatsoever. If you heat up your cpu with an external flame it won't start producing energy.

[ionbasa]

You talked as if the device would replace Alternating Current, not Air Conditioner. And no, it can't work "backwards", that makes no sense whatsoever. If you heat up your cpu with an external flame it won't start producing energy.

If I have a motor it uses electricity to drive a shaft, it converts electrical energy into mechanical energy. Now if I spin that motor it will become a generator and create current! Same principal with the wristband. Just instead of mechanical energy, it is heat energy (Delta H). 

[werto165]

first i thought wireless ac then it was alternating current then finally i thought air conditioning 

[Canoas]

If I have a motor it uses electricity to drive a shaft, it converts electrical energy into mechanical energy. Now if I spin that motor it will become a generator and create current! Same principal with the wristband. Just instead of mechanical energy, it is heat energy (Delta H). 

Yes, that is true, but if you start spinning your fans fast enough to produce a moderate voltage you'll end up frying your motherboard. Having a cooler and a generator in the same device is not that simple. Not to mention that the efficiency of thermoelectric coolers and generators are super low, I very much doubt it would be enough to power on the device.

[ionbasa]

Yes, that is true, but if you start spinning your fans fast enough to produce a moderate voltage you'll end up frying your motherboard. Having a cooler and a generator in the same device is not that simple.

Read up on: http://en.wikipedia.org/wiki/Thermoelectric_effect#Seebeck_effect

Although I hate to break it to you, yes you can. I am assuming you have some knowledge of physics. Note the images on the right. Same devices two different ways of operating.

[Evil Genius Jr.]

I'm using a thermoelectric plate to power a cell phone charger for my high school science fair, and yeah it works (not with iphones... yet)

I know I know proof lol.

[Canoas]

Read up on: http://en.wikipedia.org/wiki/Thermoelectric_effect#Seebeck_effect

Although I hate to break it to you, yes you can. I am assuming you have some knowledge of physics. Note the images on the right. Same devices two different ways of operating.

I never said anything against that. It's not the mechanism that's the problem. Like I said, you can spin your fans to produce energy but that doesn't mean your motherboard will start functioning, quite the opposite actually. The efficiency of a device that keeps changing from a cooler to a generator every few seconds when the temperature difference isn't that big will not be viable. It will simply not generate enough power and will need a completely different circuit for the generator, making it considerably more expensive just to needlessly save a bit of battery. If you don't use a different circuit then the generator will just completely fry everything just like a fan being rotated fast enough would fry your motherboard. Try applying 12V across a fan output if you don't believe me.

[ionbasa]

I never said anything against that. It's not the mechanism that's the problem. Like I said, you can spin your fans to produce energy but that doesn't mean your motherboard will start functioning, quite the opposite actually.

Why bring up a motherboard? This has nothing to do with that. Also this will never work to power a motherboard using your fans because of rectifying diodes to protect the pwm fan circuits.

[Matsy]

Dont really understand what this is supposed to be used for....

[ionbasa]

Dont really understand what this is supposed to be used for....

If you apply current to the device it can either heat or cool your writs.

[Matsy]

If you apply current to the device it can either heat or cool your writs.

 

Erm....ok?

Whats that useful for o_o

[Canoas]

Why bring up a motherboard? This has nothing to do with that. Also this will never work to power a motherboard using your fans because of rectifying diodes to protect the pwm fan circuits.

The diodes in the pwm fan aren't put there with that purpose in mind, I very much doubt they would stop anything at all. Just because a circuit uses diodes doesn't mean it's immune to reverse currents. If you connect a 12V battery to the fan outputs you will fry the motherboard, and the same would happen if you tryed to use their circuit for the cooling as a generator. You would need a completely different circuit if you want to use thermoelectric module as a thermoelectric generator. And this, as I said several times before, would make it considerably more expensive and the energy you would save would be practically 0, the effciency of a device that keeps changing between cooling and generating every 5 seconds would just be terrible.

 

EDIT: I've said everything I had to say, if you don't agree then that's fine, I will not continue this discussion.

[Canoas]

Erm....ok?

Whats that useful for o_o

They're sending pulses of hot or cold to mimick the effect that you get when you enter cold water, for example, forcing your body to adapt to the temperature. So if you're cold then it'll send pulses of cold so your body thinks it's getting even colder when it's not, causing it to increase the temperature. It's actually pretty ingenius.

[ionbasa]

The diodes in the pwm fan aren't put there with that purpose in mind, I very much doubt they would stop anything at all. Just because a circuit uses diodes doesn't mean it's immune to reverse currents. If you connect a 12V battery to the fan outputs you will fry the motherboard, and the same would happen if you tryed to use their circuit for the cooling as a generator. You would need a completely different circuit if you want to use thermoelectric module as a thermoelectric generator. And this, as I said several times before, would make it considerably more expensive and the energy you would save would be practically 0, the effciency of a device that keeps changing between cooling and generating every 5 seconds would just be terrible.

 

EDIT: I've said everything I had to say, if you don't agree then that's fine, I will not continue this discussion.

Yes, but I never said to do both at the same time, I said it could alternatively be used for electric production not do both at the same time.

[qwertywarrior]

i actually would not mind wearing the final product

[ionbasa]

The diodes in the pwm fan aren't put there with that purpose in mind, I very much doubt they would stop anything at all. Just because a circuit uses diodes doesn't mean it's immune to reverse currents. 

Diode: only allows current to flow in one way, try to apply an inverse current, and the diode will burn out, therefore protecting everything up-stream of the diode.

[totjup5]

Putting an icepack on your wrist won't replace air conditioning.

[xRAGExSounDxRIOTX]

Coming from the place that brought you the student that said that he could disprove homosexuality with magnets!  Wrong place.

 

I don't understand this. Would it be able to regulate body temperature? Which, in turn, would make AC units obsolete? It will be interesting to see the end product.

[Canoas]

Diode: only allows current to flow in one way, try to apply an inverse current, and the diode will burn out, therefore protecting everything up-stream of the diode.

No shit. That doesn't mean the diodes are in the correct place to prevent someone from putting a voltage across the output. The semiconductor devices on the pwm circuit are there to change the duty cycle. Do you know what the last block of a DC-DC converter is? A capacitor. Do you know what happens when you invert the current on a electrolytic capacitor? It explodes. It literally explodes. Having a diode somewhere inside the circuit doesn't mean crap. And even then there should only be a single diode in a pwm circuit and it's the free-wheel diode to avoid discontinities in the load current, everything else is done with thyristors and transistors, so I have no idea where you even got the notion that there are "rectifying diodes" in a pwm circuit. Not to mention that the pwm circuit is just on that single pin to provide the modulation, the other two pins have nothing to do with pwm, so why I have absolutely no idea why you even brought up the pwm circuit.

 

 

Coming from the place that brought you the student that said that he could disprove homosexuality with magnets!

That was a university in nigeria or something, not MTI..

 

 

Putting an icepack on your wrist won't replace air conditioning.

It doesn't make your wrist cold, it creates subtle pulses of temperature difference in order to trick your body into thinkiing it's getting colder or warmer. When you jump into water you'll feel really cold, but after a few minutes you'll feel fine. That's what happens when you put a icepack, it feels cold at first but then you adjust. Instead this device mimicks that first reaction over and over again with so it tricks your body into thinking it's still getting colder.