The heat-powered flashlight

[pendell]

Story (http://www.people.com/people/article/0,,20791083,00.html?xid=outbrain_sandbox). Girl has a poor friend who can't get her homework done because the batteries run out. Invents flashlight powered by body heat.

AWESOME stuff. I hope she makes a phone charger which works the same way.

Respectfully,

Brian P.

[T-Mick]

This is a sweet story, but what if it's hot outside? Do you have to put it on an ice cube?

[roseawebs]

Great flashlight story brother. Just enjoyed to read your story ;)

[HandofShadows]

Story is a couple of years old now. Wonder how it's progressing? :smallconfused:

[noparlpf]

If somebody could figure out how to turn heat back into useful energy like electricity directly (i.e., not using heat to move vapor to turn turbines) that would be amazing.

And we might have to rethink thermodynamics again.

[NecroRebel]

If somebody could figure out how to turn heat back into useful energy like electricity directly (i.e., not using heat to move vapor to turn turbines) that would be amazing.

And we might have to rethink thermodynamics again.

You mean like a thermoelectric generator? These things already exist, no rethinking of thermodynamics necessary. You're still simply taking energy in one form and converting it to another, with the inefficiency that that implies. Thermoelectric generators aren't very common because they require some very expensive materials to make and the energy you get out of even really big temperature gradients isn't really that huge - Wikipedia's article on them (https://en.wikipedia.org/wiki/Thermoelectric_generator) gives a figure of 5-8% efficiency.

Steam turbines are usually used because that is the efficient way of converting heat to electricity, despite all the potential energy lost to friction and such. Thermoelectric generators have their place, in that they've got no moving parts and are thus more durable, but they'll probably never replace turbines even if better materials are developed for them.

[Grinner]

Well, pendell, you got your wish. (http://www.huffingtonpost.ca/2015/12/23/ann-makosinski-inventions_n_8868916.html)

[pendell]

Awesome!

Respectfully,

Brian P.

[Kami2awa]

Big problem with thermoelectric generators is reliance on bismuth telluride, which is expensive, heavy and brittle.

[mike201689]

Give each flashlight