Study of The Effect of Connection Type on Piezoelectric Energy Harvester

The ability to convert mechanical energy into electrical energy by piezoelectric materials makes them suitable alternatives to use in energy harvesters. So, the efficiency of a piezoelectric energy harvester is the main limitation. One of the desired approaches to increase efficiency is using a piezoelectric array in the harvester. In this paper, a numerical method has been used for the comparative study of series and parallel array behavior in different types of input force. The effect of input force type, frequency of input force, and type of array connection on energy harvester efficiency with the proposed design have been investigated. Numerical results have been verified with experiments. Results indicated that a series connection can produce 2.2 times the maximum voltage larger than a parallel connection. Also, they show that the input force shape function is the effective parameter for a piezoelectric energy harvester with an array structure. The results show a similar effect of the input force shape function on the behavior of piezoelectrics in both types of electric connections (parallel or series). In general, it can be seen that the waveform of the output voltage after applying the load with a square function was similar to its function. Also, the change in the parameters of the input force with the sinusoidal function causes a direct change in the same character of the generated voltage waveform.