Shrink wrap heat sink

I saw this article on Gizmodo - A shrink wrap polymer that cools when a current is applied to it.

http://gizmodo.com/5036066/shrink+wrap+like-polymer-cools-when-charged-could-make-an-awesome-heatsink

Paging the laws of thermodynamics, laws of thermodynamics to the white courtesy phone please.

JDB.

ha ha JD "where the hell is the heat going then!" B!

I'm sure it still obeys the laws of thermodynamics in some form. They aren't telling us how it works in that short paragraph.. Surely they don't want to give away the mechanics of the thing until they've patented it or somehow protected their intellectual property..

http://www.engr.psu.edu/newsevents/newsdetail.aspx?NewsID=6367&NewsDate=8/8/2008#6367

http://www.sciencemag.org/cgi/content/abstract/321/5890/821

Get a university friend to pull a PDF copy for you. But it is not fun reading, nor very illuminating.

just the first sentance is enough to scare off the weak

"Applying an electrical field to a polar polymer may induce a large change in the dipolar ordering, and if the associated entropy changes are large, they can be explored in cooling applications"

hahahah

> just the first sentance is enough

That's just the Abstract, a simplified summary of the paper.

> Paging the laws of thermodynamics,...

Actually, the full-text does say "where the heat goes", in almost mundane terms. And since this is a mere refresher, not the point of the paper, I'm going to risk re-posting this snippet here:

"In an ideal refrigeration cycle, the working material must absorb entropy from the load to be cooled while it is in thermal contact with the load... The material is then isolated from the load while the temperature is increased because of an increased applied electric field... The material is then placed in thermal contact with the heat sink, and the entropy that was absorbed from the cooling load is transferred to the heat sink. The working material is then isolated from the heat sink and its temperature is reduced back to the temperature of the cooling load as the field is reduced and the process is repeated."

That's a plain old refrigerator or air-conditioner. You absorb heat (entropy) from beer, squeeze it to a higher temperature, reject heat out the back of the refrigerator, drop the temperature, and repeat. Replace freon PSI changes with V/M electric field changes.

How they move the heat from the beer to the air, contact-isolation-contact, is not discussed, left as a mere detail for the implementation team.

However: "the heat of F-P transition is 20.9 kJ/kg." Now, a J (Joule) is a small pip of heat, 0.000,000,28 KiloWatt-Hours or very near a Watt-Second, while a kg is 2 pounds plus. So 2 pounds of this stuff can soak-up 20 Watts for 1 second... and then what? Can we contact-isolation-contact and repeat faster than every second? (This is similar to asking how often a freon machine moves freon from beer to air and repeat.) If there is a KHz implementation, this thing is a real heat-mover. If there is a little rat-wheel carrying slabs of "P(VDF-TrFE) 68/32 mol% copolymers" from a hot CPU to a heatsink, it seems pretty pointless. I think it is a glimpse of a possible future technique, not something DellWay will be using next year.