IEEE Trans Ultrason Ferroelectr Freq Control. 2011 Apr;58(4):849-52. doi: 10.1109/TUFFC.2011.1878.
The effects of first-order strain gradient in micro piezoelectric-bimorph (PB) power harvesters are investigated by including the first-order gradient terms in the energy density functions. For a PB, the gradient effects can be focused on the analysis of the strain gradient effect in the thickness direction through choosing the strains and the electric displacements as the independent constitutive variables. It is shown theoretically that the first-order gradient effects have raised the natural frequency of the PB and effectively enhanced the output power density of the harvester.
通过在能量密度函数中包含一阶梯度项来研究微压电双晶片（PB）电源收集器中的一阶应变梯度的影响。对于 PB，可以通过选择应变和电位移作为独立的本构变量，将梯度效应集中在厚度方向的应变梯度效应的分析上。理论上表明，一阶梯度效应提高了 PB 的固有频率，并有效地增强了收集器的输出功率密度。
