How to convert heat into electricity?

Question

Electronics

What are the ways to convert heat into electricity, while being as miniature and silent as possible?

Answer 1

With the help of the Pelte element. It is used to cool the processor in modern computers - you can take it from there.
It needs a temperature difference to work.

Answer 2

Like this: oldradio.onego.ru/ARTICLES/RADIO/tgk.htm :)
The Peltier effect is the absorption or release of energy when current is passed through the contact of two dissimilar materials. This is how the Peltier element works. You also need the opposite effect - the Seebeck effect.
Some devices may indeed exhibit both effects.

Answer 3

Like this

Answer 4

steam engine or stirling engine

Answer 5

Stirling engine, like this , for example.