The underlying concept, pyroelectricity, is based on the use of pyroelectric materials, some of which have been known for centuries.
From the sciencedaily.com
Theophrastus made the first known reference to the phenomenon of pyroelectricity, noting that the mineral tourmaline becomes charged when heated.
From the en.wikipedia.org
This and other lattice symmetry properties result in piezoelectricity of the hexagonal and zincblende ZnO, and pyroelectricity of hexagonal ZnO.
From the en.wikipedia.org
For example, he made the first known reference to the phenomenon of pyroelectricity, noting that the mineral tourmaline becomes charged when heated.
From the en.wikipedia.org
More examples
Generation of an electric charge on certain crystals (such as tourmaline) as a result of a change in temperature
(pyroelectric) relating to or exhibiting pyroelectricity
Pyroelectricity (from the Greek pyr, fire, and electricity) is the ability of certain materials to generate a temporary voltage when they are heated or cooled. ...