Space charge measurement using pulsed electroacoustic technique and signal recovery

Dielectric properties are considered to be one of the most important properties for the effectiveness of electrically induced actuation of PVC gel actuators. To clarify the actuation mechanism from the molecular motion and polarization of PVC gel actuators in an electric field, the frequency dependent dielectric properties have been investigated by AC impedance spectroscopy. The dielectric constant and dielectric loss of the PVC gel greatly increased at low frequencies due to electrode polarization and dipole orientation. The electrode polarization for negative charge accumulation in the PVC gel was confirmed by space charge measurement. By blocking the electrode with a polytetrafluoroethylene (PTFE) sheet between the PVC gel and the cathode, there was no actuation or electrode polarization. This indicates that charge injection from the cathode and dipole orientation are important factors for the actuation of PVC gels, and electrode polarization is closely related to the actuation of PVC gels in an electric field.

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“…33,34 As discussed above, the dielectric constant greatly increased as the result of electrode polarization.…”

Section: Space Charge Densitymentioning

confidence: 88%

Relationship between electrode polarization and electrical actuation of dielectric PVC gel actuators

Ali

Hirai

2012

Soft Matter

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“…A signal processing algorithm has been employed to recover the signal. 36 In our PEA system for plaque geometry the resolution is less than 10 µm which is considered adequate in the present study.…”

Section: Pea Techniquementioning

confidence: 99%

ac aging and space-charge characteristics in low-density polyethylene polymeric insulation

Chen

Liu

et al. 2005

Journal of Applied Physics

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In the present work efforts have been made to investigate the influence of ac aging on space-charge dynamics in low-density polyethylene ͑LDPE͒. LDPE films with 200 µm were aged under various electric stress levels at 50 Hz for various times at ambient temperature. Space-charge dynamics in the samples after aging were monitored using the pulsed electroacoustic technique. It has been revealed that the space charge under ac aging conditions is related to the level of the applied field, duration of the voltage application, as well as the electrode materials. By comparing with the results of unaged sample the results from aged sample provide a direct evidence of changing trapping characteristics after ac aging. Negative space charge is present in the bulk of the material and the total amount of charge increases with the aging time. The amount of charge increases with the applied field. Charge decay test indicates that the charges are captured in deep traps. These deep traps are believed to form during the aging and related to change caused by injected charge. By using different electrode materials such as gold, brass alloy, and polyethylene loaded with carbon black, it was found that the electrode has an important role in the formation of charge, hence subsequent changes caused by charge. The charge dynamics of the aged samples under dc bias differ from the sample without ac aging, indicating changes brought in by ac aging. Chemical analysis by Fourier transform infrared spectroscope and Raman microscope reveals no detectable chemical changes taken place in the bulk of the material after ac aging. Finally, the consequence of the accumulation of space charge under ac conditions on the lifetime of the material has been discussed. The presence of deeply trapped space charge leads to an electric stress enhancement which may shorten the lifetime of the insulation system.

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“…Space charge is a term used to describe charge accumulation in a volume or area of a material under an applied electric field, and can be measured using the PEA technique. The charge distribution inside a sample becomes accessible by acoustic signal treatment ,…”

Section: Resultsmentioning

confidence: 99%

Dielectric and electromechanical studies of plasticized poly(vinyl chloride) fabricated from plastisol

Ali

Ueki

Hirai

et al. 2013

Polymer International

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Poly(vinyl chloride) (PVC) plastisol is used in many industrial applications and is considered an electrically inactive material. To explore the potential of plastisol as an electroactive material, the dielectric properties, space charge distribution, mechanical properties, internal structure and electromechanical behavior of plasticized PVC (PVC gel) prepared from plastisol by heating were investigated. The gel exhibited a large dielectric constant at low frequencies (1–1000 Hz), an asymmetric charge distribution and excellent mechanical properties. Various DC electric fields were applied to the gel placed parallel between two electrodes and the electrostatic adhesive force to the anode was measured. The results of small‐ and wide‐angle X‐ray scattering suggested that the electromechanical properties of the gel originated from the characteristics of the physical crosslinking distance (ca 20 nm) of PVC in the gel structure. Considering the dielectric properties, space charge density and adhesion force to the anode, PVC gels prepared from plastisol using the heating method have potential for use as electroactive materials. © 2013 Society of Chemical Industry

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Space charge measurement using pulsed electroacoustic technique and signal recovery

Cited by 26 publications

References 8 publications

Relationship between electrode polarization and electrical actuation of dielectric PVC gel actuators

Relationship between electrode polarization and electrical actuation of dielectric PVC gel actuators

ac aging and space-charge characteristics in low-density polyethylene polymeric insulation

Dielectric and electromechanical studies of plasticized poly(vinyl chloride) fabricated from plastisol

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