Clamping thin-film lead zirconate to a substrate unexpectedly improves piezoelectric response

https://engineering.dartmouth.edu/news/dartmouth-contributes-to-a-breakthrough-in-understanding-of-thin-film-materials

"voltage applied to most piezoelectric films would be blocked when film is clamped to substrate, but in this case the energy barrier doesn't become too high... in most materials, stretching in 1 direction leads to contraction in another. but here leads to expansion in all directions... miniaturized electronic systems... future: find a piezoelectric material with this property that is lead-free"