Bailibo Testing--Detection and analysis of the piezoelectric response of piezoelectric films under cyclic stress

Piezoelectric film is a core functional material in the fields of intelligent sensing, energy harvesting, precision driving and other fields. Its piezoelectric response characteristics under cyclic mechanical loads are the key basis for evaluating the service reliability of materials and optimizing the preparation process. Open-circuit voltage and short-circuit current testing under cyclic stress can accurately characterize the dynamic behavior of mechanoelectric coupling of piezoelectric films, providing important data support for basic materials research and device applications.

The essence of the piezoelectric effect is the reversible conversion of mechanical energy and electrical energy. When the piezoelectric film is subjected to cyclic tension, compression or bending stress, the internal electric domain undergoes directional deflection, thereby generating induced charges on the electrode surface, forming measurable open circuit voltage and short circuit current. Open-circuit voltage refers to the potential difference between electrodes when there is no external current path. Its amplitude and stability directly reflect the charge generation ability and interface state of the material; short-circuit current is the instantaneous current when the electrodes are short-circuited, reflecting the charge release rate and dynamic response characteristics of the piezoelectric film. The combination of the two can comprehensively evaluate the piezoelectric activity and mechanoelectric conversion efficiency of the material.

The testing process follows the principles of standardization and high precision to ensure the accuracy and repeatability of data. Before testing, the piezoelectric film sample needs to be pretreated to clean surface stains and impurities to ensure good contact between the electrode and the film. The sample must be placed in a constant temperature and humidity environment to eliminate interference from environmental factors. During the test, a servo-controlled mechanical loading platform is used to apply controllable periodic cyclic stress to the sample. The stress amplitude, frequency and waveform (sine wave, square wave, etc.) can be accurately adjusted according to the testing requirements. Through the high-precision voltage acquisition system (resolution up to microvolt level) and the high-sensitivity current detection module, the open-circuit voltage fluctuation and short-circuit current signal under cyclic stress are captured in real time to achieve the simultaneous acquisition and recording of force load and electrical signals.

Compared with the traditional static piezoelectric coefficient test, the piezoelectric response test under cyclic stress is closer to the actual service conditions of the material. In application scenarios such as flexible sensing and wearable devices, the piezoelectric film is subjected to repeated mechanical deformation for a long time. The attenuation law, fatigue characteristics and dynamic response stability of its piezoelectric performance directly determine the service life and reliability of the device. Through this test, the change curves of voltage and current with the number of cycles can be obtained, the performance evolution rules of the material under long-term cyclic load can be analyzed, the intrinsic mechanism of electromechanical coupling can be revealed, and scientific basis can be provided for material formula optimization, polarization process improvement and device structure design.

Currently, with the expansion of applications of piezoelectric films in high-end electronics, new energy and other fields, higher requirements have been put forward for the detection accuracy and test dimensions of piezoelectric responses. Open-circuit voltage and short-circuit current testing under cyclic stress, as an important means of characterizing the performance of piezoelectric films, can effectively make up for the limitations of single static parameter testing, help scientific researchers gain an in-depth understanding of the dynamic mechanical and electrical coupling characteristics of materials, and promote the development and industrial application of high-performance piezoelectric film materials.