本文设计了实验装置与实验方案，用于演示正压电效应与逆压电效应，并研究了机械能与电能的相互转化关系. 在正压电效应演示实验中，利用电磁铁激励压电双晶片振动，利用示波器观察激励信号与产生的电信号；电信号频率与激励信号频率保持相同，电信号幅值与激励信号幅值成正相关，电信号幅值随激励信号频率先增大后减小. 在逆压电效应演示实验中，利用直流电压源激励压电双晶片产生形变，利用光杠杆放大微小形变；压电双晶片的形变量与激励电压值成线性关系. 相比于现有演示实验，新设计的实验中研究了机械能与电能的相互转化关系，有助于加深实验者对压电效应原理的理解.

The experimental device and scheme are designed to demonstrate the positive and inverse piezoelectric effects, in which the coupling relationships between mechanical energy and electrical energy are studied. A drive signal is applied to an electromagnet to stimulate vibration of piezoelectric bimorph. Both drive signal and generated electric signal are measured by an oscilloscope. Electric signal frequency is consistent with drive signal frequency, while electric signal amplitude is positively correlated to drive signal amplitude. Electric signal amplitude first increases and then decreases with drive signal frequency. The piezoelectric bimorph is excited by DC voltage source to produce deformation, which is amplified by an optical lever. The displacement of the piezoelectric bimorph is linear with the excitation voltage. Compared with the existing demonstration experiments, the conversion relationship between mechanical energy and electrical energy are investigated in this new designed experiment, which is helpful to make participants understand deeply of the principle of piezoelectric effects.