We investigated the dependence of electromechanical coupling and the piezoelectric response of a micromachined Pb(Zr 0.52 Ti 0.48)O 3 (PZT) diaphragm on its curvature by observing the impedance spectrum and central deflection responses to a small AC voltage. The curvature of the diaphragm was controlled by applying air pressure to its back. We found that a depolarized flat diaphragm does not initially exhibit electromechanical coupling or the piezoelectric response. However, upon the application of static air pressure to the diaphragm, both electromechanical coupling and the piezoelectric response can be induced in the originally depolarized diaphragm. The piezoelectric response increases as the curvature increases and a giant piezoelectric response can be obtained from a bent diaphragm. The obtained results clearly demonstrate that a high strain gradient in a diaphragm can polarize a PZT film through a flexoelectric effect, and that the induced piezoelectric response of the diaphragm can be controlled by adjusting its curvature.
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机译:我们通过观察阻抗谱和对小交流电压的中心偏转响应,研究了微机械加工的Pb(Zr 0.52 Ti 0.48)O 3(PZT)膜片的机电耦合和压电响应的曲率。隔膜的曲率通过向其背面施加气压来控制。我们发现,去极化的平坦振动膜最初不会表现出机电耦合或压电响应。然而,在将静态气压施加到隔膜上时,在最初去极化的隔膜中会引起机电耦合和压电响应。压电响应随着曲率的增加而增加,并且可以从弯曲的振动膜获得巨大的压电响应。获得的结果清楚地表明,隔膜中的高应变梯度可以通过柔电效应使PZT膜极化,并且可以通过调节其曲率来控制隔膜的感应压电响应。
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