Engine by capillarity. It's possible?

[gegyx]

Already prototypes

[dedeleco]

We can make a motor based on any reversible physical or chemical phenomenon where thermodynamics intervenes with changes depending on the temperature, and other variables, pressure, chemical composition, etc.
It suffices to describe a generalized thermodynamic cycle of Carnot.
The yield is a function of these physical properties and of the heat losses.
We can also use oil on water (or soap) with the surface of this oil which replaces the volume of gas in a piston and take out exactly the same thermodynamic arguments!
We can use the dissolution of a body in water like sugar or other and its precipitation at different temperatures too !!
Capillarity is visible in any finely divided body such as porous flower pots, toilet paper, concrete blocks, walls soiled by salt deposits, etc ... and the ascent height is higher the finer it is divided (typically 20cm is easy in a concrete block).
If the height (or surface tension) changes depending on the temperature you can dig your brains to find a body with large variations and design a micro motor with good efficiency similar to the Stirling engine or the steam engine !!!
One can also use the piezoelectric effect which changes strongly with the temperature to generate movements and electric currents.
A rubber band was used to mount fun engines with hot and cold !!
etc ...
Finally, plants and trees are very efficient in using capillarity and other phenomena to raise the sap up to almost 100 meters high in the largest trees !!
Biologists are trying to understand their tips at the cell level, in particular whether it is by capillary action or by suction depression ??