Yes, flexoelectricity could be useful. But flexoelectricity in ice, which is what this paper is about, I think will have no applications for machines, since nobody is building machines out of ice..
I don't have any idea how flexoelectricity could be used in a machine made of ice. But that's why I wouldn't rule it out. How about medical nanomachines made mainly of ice so they dissolve when their allotted lifespan is up?
People have definitely tried! Keyword "project habbakuk".
https://jaspermuseum.org/habbakuk-1943-model-ice-sawdust-shi...
The largest HN thread I found is:
https://news.ycombinator.com/item?id=40199679
I don't have any idea how flexoelectricity could be used in a machine made of ice. But that's why I wouldn't rule it out. How about medical nanomachines made mainly of ice so they dissolve when their allotted lifespan is up?