Effect of the deformation dependent permittivity on the actuation of a pre-stretched circular dielectric actuator

Zeng, Chuan; Gao, Xiaosheng

doi:10.1016/j.mechrescom.2019.103420

Cited by 6 publications

(3 citation statements)

References 34 publications

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“…Previous studies have shown that the dielectric constant can indeed be affected by external strain [12][13][14][15][16][17][18]. For example, Vu-Cong et al [19] and Wissler et al [20] experimentally found that the dielectric constant of VHB4910 decreased at stretching deformation.…”

Section: Introductionmentioning

confidence: 98%

Strain Effect on Dielectricity of Elastic Thermoplastic Polyurethanes

Wang,

Yang,

Xie

et al. 2024

Preprint

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Dielectric elastomers, such as thermoplastic polyurethanes (TPU), are widely used as dielectric layer, emulation layer and substrate of flexible and stretchable devices. To construct capacitors and actuators that work stably upon deformation, it has become an urgent need to investigate the evolution of dielectricity under stress and strain. However, the lack of effective methods for estimating the dielectric constant of elastomers under strain poses a big challenge. This article reports a device for in-situ measuring the dielectric constant of TPU under strain. It is found that upon stretching TPU to a strain of 400%, its dielectric constant decreases from 8.47 to 2.94. In addition, combined Fourier-transform infrared spectroscopy, X-ray scattering technique, and atomic force microscopy have been utilized to characterize the evolution of microstructure under strain. The investigation under tensile strain reveals that a decreased density and average size of polarized hard domains, along with a tendency of the molecular chains to align in parallel with the tensile stress. The evolution of the microstructures results in a reduction of the dielectric constant parallel to the electric field in TPU. Our work provides valuable experimental reference for improving the stability of flexible sensors and actuators based on dielectric elastomers.

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Section: Introductionmentioning

confidence: 98%

Strain Effect on Dielectricity of Elastic Thermoplastic Polyurethanes

Wang,

Yang,

Xie

et al. 2024

Preprint

View full text Add to dashboard Cite

show abstract

“…Previous studies have shown that the dielectric constant can indeed be affected by an external strain [ 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. For example, Vu-Cong et al [ 19 ] and Wissler et al [ 20 ] experimentally found that the dielectric constant of VHB4910 decreased at stretching deformation.…”

Section: Introductionmentioning

confidence: 99%

Strain Effect on Dielectricity of Elastic Thermoplastic Polyurethanes

Wang,

Yang,

Xie

et al. 2024

Polymers

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Dielectric elastomers, such as thermoplastic polyurethanes (TPUs), are widely used as the dielectric layer, encapsulation layer, and substrate of flexible and stretchable devices. To construct capacitors and actuators that work stably upon deformation, it has become urgent to investigate the evolution of dielectricity under stress and strain. However, the lack of effective methods for estimating the dielectric constant of elastomers under strain poses a big challenge. This study reports a device for the in situ measurement of the dielectric constant of TPU under strain. It is found that upon stretching TPU to a strain of 400%, its dielectric constant decreases from 8.02 ± 0.01 to 2.88 ± 0.25 (at 1 MHz). In addition, combined Fourier-transform infrared spectroscopy, the X-ray scattering technique, and atomic force microscopy were utilized to characterize the evolution of the microstructure under strain. The investigation under tensile strain reveals a decreased density and average size of polarized hard domains, along with a tendency of the molecular chains to align in parallel with the tensile stress. The evolution of the microstructures results in a reduction in the measured dielectric constant in TPU.

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“…Using deformation dependent permittivity in a dielectric-based tube, Ogden and Dorfman [47] investigated the elastic response of a tube. Motivated by this idea, Zeng et al, [48], recently, employing the deformation dependent permittivity, studied the effect of parameters such as instability, loss of tension and dielectric breakdown of a circular actuator at various applied stretches.…”

Section: Introductionmentioning

confidence: 99%

Multi-Trigger Thermo-Electro-Mechanical Soft Actuators under Large Deformations

et al. 2020

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Dielectric actuators (DEAs), because of their exceptional properties, are well-suited for soft actuators (or robotics) applications. This article studies a multi-stimuli thermo-dielectric-based soft actuator under large bending conditions. In order to determine the stress components and induced moment (or stretches), a nominal Helmholtz free energy density function with two types of hyperelastic models are employed. Non-linear electro-elasticity theory is adopted to derive the governing equations of the actuator. Total deformation gradient tensor is multiplicatively decomposed into electro-mechanical and thermal parts. The problem is solved using the second-order Runge-Kutta method. Then, the numerical results under thermo-mechanical loadings are validated against the finite element method (FEM) outcomes by developing a user-defined subroutine, UHYPER in a commercial FEM software. The effect of electric field and thermal stimulus are investigated on the mean radius of curvature and stresses distribution of the actuator. Results reveal that in the presence of electric field, the required moment to actuate the actuator is smaller. Finally, due to simplicity and accuracy of the present boundary problem, the proposed thermally-electrically actuator is expected to be used in future studies and 4D printing of artificial thermo-dielectric-based beam muscles.

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Effect of the deformation dependent permittivity on the actuation of a pre-stretched circular dielectric actuator

Cited by 6 publications

References 34 publications

Strain Effect on Dielectricity of Elastic Thermoplastic Polyurethanes

Strain Effect on Dielectricity of Elastic Thermoplastic Polyurethanes

Strain Effect on Dielectricity of Elastic Thermoplastic Polyurethanes

Multi-Trigger Thermo-Electro-Mechanical Soft Actuators under Large Deformations

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