Design and fabrication of a cross-shaped piezoelectric generator for energy harvesting

In this paper, a cross-shaped piezoelectric generator was proposed for generating electric power at low frequency range. The generator has centrosymmetric four elastic body legs which have equivalent vibration mode. The centrosymmetric structure of the generator is able to generate in each elastic body legs at the same time using only one vibration source. Vibration is transferred from center of the generator and is equally applied to each elastic body leg. So each elastic body leg of the generator has the same resonance frequency and vibration mode. Resonance and output characteristics of the generator were analyzed by FEM program. Output characteristics of the generator could be changed by elastic body length, elastic body thickness, ceramic width, ceramic thickness and additional mass at the edge of elastic body legs. Based on FEM result, a generator was fabricated and experimented. As a result, resonance frequency of the generator was verified lower than 35 Hz. So we confirmed generating possibility of the generator at low frequency range.