On the strain-gradient effects in micro piezoelectric-bimorph circular plate power harvesters

摘要

We analyze the first-order gradient effects in micro piezoelectric-bimorph circular plate (PBCP) power harvesters by including the first-order gradient terms in the energy density functions. Considering that the dimension of a PBCP is much smaller in the thickness direction than the in-plane dimensions, the gradient effects can be focused on analysis of the strain-gradient effects in the thickness direction through choosing the strains and the electric displacements as the independent constitutive variables. The paper has shown theoretically that the first-order gradient effects have induced shift in the natural frequency of a PBCP structure and resulted in a small change in the harvester performance.