A team in Belgium has been making real progress on one of the holy grails of portable electronics, a system that harvests the waste body heat of the user and turns that heat into power to run things like a call phone. And, bonus for constantly overheated guys like me, the surface area covered by the device, be it armband, headband, or whatever, stays cool no matter how hot the weather gets.
The physical principles of this have been known for decades. What makes the work of this team special is that, from what I can see, they're putting in the time to figure out things like "how do we build such a system so that it can be put in the laundry?" and "how do we optimize manufacture for price and durability?" as well as aggregating the knowledge out there from the work of others. In short, this isn't a bunch of theoreticians. It's a bunch of folks working to get practical, real world products to market. Soon.Picture walking around mid-summer in miserably hot, exhausting weather, with a nice wide band of cool material along your inner arm, back, or neck. Makes the prospect of all kinds of things look a lot more realistic and fun to me. Back when I still hit the massive tech trade shows at infamously poorly air-conditioned venues like The Boston Menace That Must Not Be Named, there were always guys wearing those dorky-looking Sharper Image neck chiller dealies and I've got to admit, they reliably punked all the rest of of us at a whole bunch of things at the shows because they simply didn't get tired as fast.
Reading the actual paper I see that "the produced power depends on the thickness of a [thermal energy generator] and its size: the thicker the TEG, the better its power generation, while the larger the TEG, the less power per unit area is produced." Interesting. This gives us a good sense of the dynamics of it. Also "if … PV cells cover the TEG, the joint power generation improves with no increase in the system weight and size."
Given the megadorky headband they're demoing, clearly the technology has a ways to go but I'll betcha we'll see early implementations at Burning Man in a couple years, hopefully sooner.
Keep in mind, such systems can be used for a hell of a lot more than recovering heat generated by the human body. Picture some of these on a laptop turning that waste heat back into usable power. Kinda like regenerative braking or cogeneration. Or, on a much more massive scale, picture these things recovering waste heat from a car engine. Now we're talking serious amounts of power.
In addition, this kind of thing may well be useful for the implementation of other non-photovoltaic "solar power" systems. Picture some of these hooked up to fresnel lens on the roof of a car to power the fan. If the price goes down far enough, maybe even to power a modest chiller for the vehicle or for a remotely-placed small structure.
Also keep in mind that if such systems become widespread, they will cut down considerably on demand for batteries. Not only is this good for the environment simply because that's so much less in the way of toxic manufacturing, it also cuts demand for batteries, which makes things like fully electric cars more realistic by cutting the purchase and ownership prices.To say the least, I wish them the very best.