Thermos bottles can keep foods and drinks hot for a long time, but not indefinitely. Microwaves are great for reheating things, but they can't heat thermoses.
To overcome these limitations, I propose a special thermos bottle lid, with a microwave embedded into it.
When you want to consume the contents of the thermos, you simply press a button on the outside of the lid, and the rechargable battery (or capacitor) powers the microwave for several seconds.
A digital thermometer lets the user know how hot the food is, and a digital thermostat can be used instead of a timer, to control how long the reheat process is active.
To conserve battery life, the thermos can also be operated while plugged into an electrical outlet.-- goldbb, Jun 08 2009 Ok, maybe instead of saying "thermos," I should have said, vacuum flask or dewar flask.
Wikipedia says, "Thermos, their tradename for their flasks, remains a registered trademark in some countries but was declared a genericized trademark in the U.S. in 1963 as it is colloquially synonymous with vacuum flasks in general. In fact, it is far more common for Americans to use the term thermos than vacuum flask." Since I'm an American, I hope you'll forgive me for using "thermos," when I meant vacuum flask.
That first link points to a foam insulated container, which is made under the Thermos brand label, but is not a vacuum flask (it uses foam insulation). Perhaps more importantly, it doesn't have a microwave in it... it is merely microwave safe.
None of the other links even indicate how they're insulated.
Naturally, any stainless steel vacuum thermos, or metallized glass vacuum thermos, cannot be put inside of a microwave (or at least, not with useful results).
However, if the microwave emmiter is inside of the flask, the reflective metal (or metallized glass) interior should be perfect for ensuring that any microwaves which pass through the top region of the food, will reflect in a way that gives them another chance to reach the food.-- goldbb, Jun 09 2009 As far as I know, all vacuum flasks are either made of metal, or are made of glass with a metal coating.
If you stick one in a microwave oven, that metal will reflect the microwaves, preventing the contents of the flask from being heated.
The reason a foam insulated flask can be microwaved is that the microwaves pass right through the foam as if it weren't there.-- goldbb, Jun 09 2009 Won't the microwave radiation only have access to the top surface of the flask's contents, whereas in a radiotransparent container in a regular microwave oven it has access to all sides?-- notexactly, Jun 14 2019 If you build a lump of a suitably radioactive isotope into the flask, the contents will stay hot* indefinitely.
*There may also be some slight neutron activation of the beverage.-- 8th of 7, Jun 14 2019 There's got to be a market for neutron-activated beer.-- MaxwellBuchanan, Jun 14 2019 A dirty martini but a dirty beer? Maybe a dirty depth charge.-- wjt, Jun 15 2019 Best thing about this idea is that, if the microwave is battery powered, you can just put the battery in backwards and it will chill a cold drink.-- MaxwellBuchanan, Jun 15 2019 //put the battery in backwards and it will chill a cold drink//
booooo! hisssssss-- Voice, Jun 20 2019 random, halfbakery