More than 90% of piezoelectric actuator failures are due to cracks. Micro cracks are often created in the piezoelectric wafer during the manufacturing process already. Under normal operation (deflection) the inertial force experienced by the piezo actuator (particularly when driven by DC and “rectangular” signal pulses) can induce high cyclic stress (tensile/compression) onto the piezo layer. As the layer consists of a brittle, ceramic material the micro cracks begin to grow under this cyclic stress, causing a reduction in performance of the piezo actuator. These cracks eventually propagate throughout the entire wafer, resulting in total failure. Cracks may also be caused by thermal shocks associated with soldering, handling and other mechanical impact.