Piezoelectric energy harvesters (EHs) are designed to operate at resonance in order to have the most electric power harvested. Three challenges have been confronted by these EHs: (1) low output power scavenged from low frequency vibrations, (2) limited effectiveness of harvesting mechanism in a narrow band, and (3) being unidirectional. To overcome these challenges, in this thesis a novel 3D configuration is proposed and the proposed configuration has more numbers of natural frequencies less than 500 hertz and more numbers of peaks in the frequency response function of the structure in response to base acceleration excitation compared to the traditional configuration of contilever beam. This novel configuration leads to the increase in the bandwidth and the produced power of the harvester. The proposed harvester has the ability to vibrate and bend in different directions which will be resulted in decrease in the magnitude of the natural frequencies of the structure. In this research, after introducing a 3D novel configuration and placing piezoelectric patches in appropriate locations, open circuit voltage plots produced on the piezoelectric patches are derived. Afterwards, in order to maximize the surface surrounded by produced voltage versus frequency plot, the longitudinal dimensions of the proposed structure are optimized by Hook-Jeeves method. At the end, electrical responses of the proposed harvester and its corresponding contilever and space frame ones such as produced voltage, current and power are obtained and compared. Keywords: Energy harvesting, Piezoelectric, Wideband, Produced Power, Optimization, Hook-Jeeves method