Application Cases

Experiment Name: High-Power Testing Platform for Piezoelectric Materials Based on Constant Voltage Method

Research Direction: Focusing on the field of piezoelectric materials, the core research direction is to explore the impact mechanism of PT content on the performance of PMN-PT single crystals in high-power application scenarios, and to build a corresponding testing platform to obtain key data to support the design of related devices. Piezoelectric materials, which can convert mechanical energy and electrical energy, play a significant role in numerous fields such as sensors, actuators, and high-precision positioning systems. As a new type of piezoelectric material, PMN-PT (lead magnesium niobate-lead titanate) single crystals have higher piezoelectric coefficients, electromechanical coupling coefficients, and mechanical quality factors compared to traditional polycrystalline piezoelectric materials, and their use in research and industrial applications is becoming more widespread.

(1) Piezoelectric Material Performance Research: Piezoelectric materials are widely used in many fields, and PMN-PT single crystals, as a new type of piezoelectric material, have significant advantages. However, previous research has mostly focused on low-power scenarios, and there is a lack of understanding of their performance under high-power conditions. This research focuses on the performance of PMN-PT single crystals under high-power conditions. By changing the key variable of PT content, we delve into its impact on material performance. We study the changes in key parameters such as piezoelectric coefficients, elastic coupling coefficients, electromechanical coupling coefficients, and mechanical quality factors of PMN-PT single crystals with different PT contents under high-power excitation, thereby gaining a comprehensive understanding of the material's performance characteristics in high-power applications.

(2) Building a High-Power Testing Platform: To achieve the above research goals, a complete high-power testing platform based on the constant voltage method has been built. An improved constant voltage method was selected, optimizing the triggering mechanism to reduce self-heating and depolarization of piezoelectric single crystals, ensuring the accuracy of experimental data. The platform integrates equipment such as a signal generator, high-voltage amplifier, and oscilloscope. The signal generator produces a frequency-sweeping signal, which is amplified by the high-voltage amplifier and then applied to the piezoelectric material. The oscilloscope monitors the circuit voltage and current, thereby recording and analyzing the material's response under high-power excitation, providing data support for the research.

(3) Providing a Basis for Device Design: The ultimate goal of studying the impact of PT content on the high-power performance of PMN-PT single crystals is to provide reliable data support for the design of sensors or transducers with PMN-PT as the sensitive element. Clarifying the performance changes of materials with different PT contents under high-power conditions helps engineers to precisely select PMN-PT single crystals with the appropriate PT content when designing devices, based on actual application requirements such as sensor sensitivity and transducer energy conversion efficiency. This, in turn, optimizes device performance, enhances their reliability and stability in actual operation, and promotes technological development and innovation in related fields.

Experiment Objective: To study the performance changes of PMN-PT single crystals with different PT contents under high-power voltage excitation.

Testing Equipment: Signal generator, ATA-3080 power amplifier, temperature monitoring equipment, material parameter measurement equipment (impedance analyzer and meter), etc.

Experiment Process: Currently, there are three main methods for high-power testing systems: constant voltage method, constant current method, and transient pulse method. This study adopts a testing method based on the improved constant voltage method. By improving the triggering mechanism, piezoelectric single crystals do not need to work under high electric field excitation for a long time, reducing self-heating and preventing depolarization of piezoelectric materials. Figure 1 shows the flowchart of the testing system based on the improved constant voltage method. As shown in Figure 1, the signal generator produces a frequency-sweeping signal, which is amplified by the high-voltage amplifier (Xi'an Aigtek ATA-3080) and then input into the piezoelectric material. The piezoelectric material is clamped at the center point, with the surrounding area kept in a free state. The oscilloscope is connected to voltage and current probes to monitor the circuit voltage and current, and the collected data is output to a computer for analysis. The frequency-sweeping method records the current and voltage across the piezoelectric transducer. Due to the impedance characteristics of the material, impedance is proportional to the current value. Therefore, the corresponding current curve can be used to plot the impedance curve, which in turn determines the material's resonant and anti-resonant frequencies. These frequencies are crucial for further calculating material parameters.

Figure 1: Constant Voltage Method Testing System

Experiment Results: The results show that the increase in PT content significantly changes the performance of piezoelectric materials, leading to phase transitions. For PMN-PT single crystals with 26% PT content, under 8W power excitation, the piezoelectric coefficient increased by 25%, the compliance coefficient increased by 12%, the electromechanical coupling coefficient increased by 17%, and the mechanical quality factor decreased by 73%. For PMN-PT single crystals with 29% PT content, under 4.49W power excitation, the piezoelectric coefficient increased by 33%, the compliance coefficient increased by 20%, the electromechanical coupling coefficient increased by 21%, and the mechanical quality factor decreased by 78%. For PMN-PT single crystals with 33% PT content, under 1.24W power excitation, the piezoelectric coefficient increased by 20%, the compliance coefficient increased by 30%, the electromechanical coupling coefficient increased by 20%, and the mechanical quality factor decreased by 55%. These results indicate that higher PT content makes PMN-PT single crystals more sensitive to thermal effects in high-power applications, thereby reducing power tolerance and increasing the risk of depolarization. This study, for the first time, provides a detailed description of the performance of PMN-PT single crystals with different PT contents in high-power applications, showing significant differences from previous studies and filling the gap in the literature.

Figure 2: Elastic compliance coefficients, piezoelectric coefficients, electromechanical coupling coefficients, and mechanical quality factors of PMN-PT single crystals with different PT contents

Product Recommendation: ATA-3080C Power Amplifier

Figure: Specifications of the ATA-3080C Power Amplifier