The following article appeared in a copy of New Scientist awhile back.
" HOT ANSWER TO SHAKY PROBLEM
To damp down problem vibrations in aircraft, cars, buildings and power tools researchers working for the US
army in Virginia have designed a material that dissipates the vibrational energy as heat (US 2005/0073222).
The plastic or concrete materials contain particles of piezoelectric ceramic and a web of conductive wires. When
the ceramic vibrates, the particles generate electricity, which heats the wires. The heat is absorbed by the
surrounding material and dispersed into the air. The loss of energy to the piezoelectric material damps the vibrations before they build and begin to resonate."
Skimming through the patent I couldn't find any suggestions that they should use the generated heat for anything. This
is understandable since they were looking to reduce vibrations and not generate power. It does give rise to a couple of possible applications though.
1. Line the floors in hydroelectric plants with this material to take advantage of the vibrations generated by the huge turbines in there. If nothing else, there might be enough energy to cut down on the power needs of the dam itself.
2. Line the body of aircraft with this material in such a way that if the plane lost electrical power the system could be quickly converted from dissipating heat to converting it into electrical energy.
Of course, both of these ideas might already be tucked into the patent somewhere (or left out because they were unfeasible). I'm just adding the idea here in case the oversight was accidental.