Colour changing platic -- that reacts to impact?

Does anyone know of a plastic or pigment coating that can permanently change colour from impact or from a small electrical pulse, such as one generated by piezoelectrics?

I am aware of thermal sensitive plastics, but they often require a significant amount of energy before they change or they change only temporarily at a specific temperature (e.g. 125C).

Any hints?

Thathertz,

I don’t know where you’re going with this, but thought this link might prove helpful; not too in depth, but perhaps an alternate direction in thinking might come to mind.

http://tt.tennis-warehouse.com/archive/index.php/t-58804.html

thanks for the interesting link

Specifically I am looking for a plastic that could change colour from a small electrical charge. The thread definitely touches on a similar idea.

–I can’t believe that there isn’t anything out there like it.

… it just occurred to me that there is a transparent “glass” material that shifts to opaque when energized.

I may, however, be a “liquid crystal” vs. a “plastic”