Qucs-based development of an energy harvester compact model

In the paper a simple compact model of a transfer of a mechanical energy into an electrical energy is presented. The mechanical energy is stored in a vibrating bimetallic membrane with an electret layer. The membrane vibrations are forced by a set-up consisting of a cold and hot surfaces. During the vibrations this set-up acts as a variable capacitor with one of the electrodes being constantly charged. The charge stored on the other plate of this capacitor varies periodically and is transferred to the external storage capacitor via a simple Graetz circuit. Acompact model of this mechanism has been derived and implemented in an open-source Quite Universal Circuit Simulator (Qucs) program as a circuit including a specific Equation-Defined Device component. The simulation data have been compared with experimental ones, demonstrating promising features of the proposed approach.