Scientists Find That Ice Generates Electricity When Bent

However, it seems that it's a similar but different phenomenon called "flexoelectricity" which was discovered around 1964. It was also predicted before discovery.

Bing Copilot helped me find an article which looks like a good overview of flexoelectricity, although mostly over my head.

https://arxiv.org/pdf/1307.0132

   "First-principles theory and calculation of flexoelectricity"
   Jiawang Hong and David Vanderbilt

Flexoelectricity (FxE) describes the linear coupling between electric polarization and a strain gradient, and is always symmetry-allowed because a strain gradient automatically breaks the inversion symmetry. This is unlike the case of piezoelectricity (coupling of polarization to strain), which arises only in noncentrosymmetric materials.

It goes on to say that interest has been revived after ~50 years because of finding ways to make the effect ~3 orders of magnitude stronger, and because nanoscale structures also magnify the effect.

The earliest reference is to a Soviet physics journal which I assume is not online:

S. M. Kogan, Sov. Phys. Solid State 5, 2069 (1964)