Application Cases

Experiment Name: Analysis of Output Characteristics of Electrostatic Enhanced Electric Field Energy Harvesters Based on Electrets

Testing Equipment: ATA-7010 high-voltage amplifier, waveform generator, digital oscilloscope, energy harvester, etc.

Figure 1: Structural Flowchart of the Electric Field Structure Domain Testing System

Experiment Process:

The testing process involves placing the harvester on the horizontal surface of a self-made electric field. The initial digital preset values include the digital waveform generator, high-voltage amplifier, and the relative position of the electrode plate electric field. The testing conditions are selected based on frequency (Hz) and field strength (E). The alternating voltage signal is measured and calculated using the digital oscilloscope to feedback and adjust the effective electric field. An electrostatic voltmeter is used to measure the output current and voltage of the energy harvester after being driven by the electric field force, and the results are recorded. The output power of the harvester is calculated using the formula P=U2/R, thereby establishing the relationship between the output power and environmental conditions (such as field strength, force, frequency, etc.).

Figure: Physical Diagram of the Electric Field Structure Domain Testing System

From the theoretical analysis of energy harvesting, it is known that the output voltage is positively correlated with the surface charge quantity, which in turn is positively correlated with the surface potential. The instruments can directly measure the surface potential. As known from the preparation of electrets in Chapter 2, the surface charge trap stability is related to the charging factors. Therefore, experiments were conducted under the same electric field and frequency conditions to observe different surface potentials of high-insulation polymer films. The experimental conditions were a generator output voltage of 20Vp-p, a frequency of 40Hz, a gain of 50, and an optimal film thickness of 30um. The surface potentials of the high-insulation polymer films were selected as -300V, -400V, -500V, -600V, and -700V. The output voltages obtained under the given experimental conditions for films with different surface potentials are shown in Figure 3.

Figure 3: Influence of Surface Potential on Output Voltage

Experimental Results:

As can be seen from the figure, the higher the surface potential of the electret film, the greater the output voltage of the electric field energy harvester. This confirms the proportional relationship between the surface potential of the electret film and the output power as analyzed in the theory. Therefore, under the condition of optimal electret charging, materials with high surface potential should be used as much as possible. In this experiment, an electret material with a surface potential of -700V was selected.

From the above theoretical analysis, it is known that the resonant frequency point and the size of the electric field energy harvester structure are significantly related to the material properties.

Voltage Amplifier Recommendation: ATA-7010

Figure: Specification Parameters of the ATA-7010 High-Voltage Amplifier

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