Switching loss reduction in nonlinear piezoelectric conversion under pulsed loading

Energy conversion enhancement of piezoelectric materials has been subject to intensive research over the last decade. Among the proposed solutions (for instance, single crystal), it has been shown that applying a simple and low-cost nonlinear treatment to the voltage output can significantly increase the conversion abilities of such materials. However, such an approach also adds significant electrical losses, dramatically reducing the available electric energy generated from the mechanical excitation. Such an observation is even more important when the energy in the system is limited, for example when the structure is submitted to a pulsed excitation. The purpose of this paper is to describe an efficient approach for reducing such losses, based on the transfer of the electrostatic energy when it starts to decrease. It is shown that such an approach allows increasing the converted energy by a gain up to a factor of 3, especially for weakly coupled electromechanical systems.