Boeing Testing "Smart Rotor"

Interestingly enough, Kaman has had a similar system, albeit not one with piezoelectrics, and likely with a much slower response time, on its intermeshing rotor helos for years.

Smart rotor on trial-05/06/2007-Flight International
Boeing is to test a smart helicopter rotor in a NASA windtunnel to verify the vibration, noise and performance improvements expected in forward flight with in-blade active flaps. The modified MD 900 commercial-helicopter rotor system was tested on a whirl tower in early 2004, demonstrating reduced hover vibration.

Testing of the 10.4m (34ft)-diameter rotor at NASA Ames Research Center's 12 x 24m windtunnel in California will be conducted under a $3 million US Defense Advanced Research Projects Agency contract. The smart-material actuated rotor was built and whirl-tested under a previous DARPA programme.

Each of the rotor's five blades has an active trailing-edge flap