scholarly journals Effects of Thinner Compliant Electrodes on Self-Clearability of Dielectric Elastomer Actuators

Actuators ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 121
Author(s):  
Gih-Keong Lau ◽  
Li-Lynn Shiau ◽  
Soo-Lim Chua
Keyword(s):  
Breakdown Strength ◽  
Dielectric Strength ◽  
Dielectric Elastomer ◽  
Thickness Effect ◽  
Substrate Thickness ◽  
Scanning Calorimetry ◽  
Electrode Coating ◽  
Dielectric Elastomer Actuators ◽  
Thin Electrode ◽  
Compliant Electrodes

A metalized plastic capacitor stands a higher chance to clear faults when embodied with thinner electrodes. However, it is not clear whether the same thickness effect applies to carbon-based compliant electrodes in clearing the defects in dielectric elastomer actuators (DEA). This experimental study showed that charcoal-powder compliant electrodes act like fuses and current limiters to successfully clear the defects of an acrylic dielectric elastomer actuator, provided a very thin electrode coating. For example, DEAs with 3 μm thick (average) charcoal-powder electrodes fast cleared faults and sustained high breakdown strength (300 to 400 MV/m), but the ones with thicker charcoal-powder electrodes (30 μm thick on average) succumbed to persisting breakdowns in a weaker electric field (200 to 300 MV/m). Thermo-gravitational analysis and differential scanning calorimetry showed that dielectric elastomer (3M VHB F9473PC) started to ignite at 350 ∘C, and charcoal powders (Mungyo charcoal pastel MP-12CP) started burning above 450 ∘C. This confirmed that flash ignition and its damping of charcoal powder is possible only with a very thin electrode coating relative to acrylic elastomer substrate thickness. Too thick of a charcoal-powder coating could lead to the spread of burning beyond the initial flash point, and incomplete burning that punctures the dielectric layer but shorts across opposite electrodes. With this insight, one can design self-clearable electrodes to improve the dielectric strength of dielectric elastomer actuators.

scholarly journals Exploiting Stretchable Metallic Springs as Compliant Electrodes for Cylindrical Dielectric Elastomer Actuators (DEAs)

Micromachines ◽  
2017 ◽  
Vol 8 (11) ◽  
pp. 339 ◽  
Author(s):  
Chien-Hao Liu ◽  
Po-Wen Lin ◽  
Jui-An Chen ◽  
Yi-Tsung Lee ◽  
Yuan-Ming Chang
Keyword(s):  
Dielectric Elastomer ◽  
Dielectric Elastomer Actuators ◽  
Compliant Electrodes

Development of Dielectric Elastomer Actuators - Part II: Preparation of the High Dielectric Constant Film Actuators Containing BaTiO3 Particles

2012 ◽  
Vol 557-559 ◽  
pp. 1869-1874 ◽  
Author(s):  
Takeshi Fukuda ◽  
Zhi Wei Luo ◽  
Aya Ito
Keyword(s):  
Particle Size ◽  
Dielectric Constant ◽  
High Dielectric Constant ◽  
Volume Fraction ◽  
Breakdown Strength ◽  
Electrical Breakdown ◽  
Dielectric Elastomer ◽  
Dielectric Elastomer Actuators ◽  
Electrical Breakdown Strength ◽  
High Dielectric

Dielectric elastomer actuators with high dielectric constant and flexibility were prepared. These actuators were fabricated by the composite of barium titanate (BaTiO3) and polyester-type thermosetting polyurethane (TSU), which was molecularly-designed to become less hard segment content. In this study, the effects of particle size, volume fraction and manufacturing method of BaTiO3 were investigated. In addition, the mechanically-stretched effect in composites was also evaluated. It turned out that the electrical breakdown strength increased with the increase of particle size of BaTiO3 and in volume fraction as well as the use of BaTiO3 synthesized by the oxalate method. In addition, prestrain of composites also raised the electrical breakdown strength. However, the addition of BaTiO3 to polyurethane didn’t contribute to the actuation under a lower electric field.

scholarly journals Dielectric elastomer actuators based on stretchable and self-healable hydrogel electrodes

2019 ◽  
Vol 6 (8) ◽  
pp. 182145 ◽  
Author(s):  
Yang Gao ◽  
Xiaoliang Fang ◽  
Danhquang Tran ◽  
Kuan Ju ◽  
Bo Qian ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Elastomer ◽  
Soft Robotics ◽  
Self Healing ◽  
High Electrical Conductivity ◽  
Relative Resistance ◽  
Resistance Change ◽  
Dielectric Elastomer Actuators ◽  
Compliant Electrodes ◽  
Pva Hydrogel

Dielectric elastomer actuator (DEA) based on dielectric elastomer holds promising applications in soft robotics. Compliant electrodes with large stretchability and high electrical conductivity are the vital components for the DEAs. In this study, a type of DEA was developed using carbon nanotube/polyvinyl alcohol (CNT/PVA) hydrogel electrodes. The CNT/PVA hydrogel electrodes demonstrate a stretchability up to 200% with a small relative resistance change of approximately 1.2, and a self-healing capability. The areal strain of the DEA based on the CNT/PVA hydrogel electrodes is more than 40%, much higher than the ones based on pure PVA electrodes.

Characterization of slide ring materials for dielectric elastomer actuators

2021 ◽  
Author(s):  
Jun Shintake ◽  
Koya Matsuno ◽  
Kazumasa Baba ◽  
Hiromitsu Takeuchi
Keyword(s):  
Electric Fields ◽  
High Performance ◽  
Mechanical Performance ◽  
Dielectric Strength ◽  
Dielectric Elastomer ◽  
Elongation At Break ◽  
Dielectric Elastomer Actuators ◽  
Elastomeric Materials ◽  
Mechanical Performances

Abstract This paper investigates the characteristics of sliding ring materials (SRMs), which are promising elastomeric materials for dielectric elastomer actuators (DEAs). Two different types of SRMs with Young's modulus of 0.8 MPa and 3.3 MPa, respectively, are prepared, and their material and mechanical properties and electro-mechanical performances at electric fields of up to 30 V/um are characterized. For comparison, the same tests are also performed on several commercially available elastomers: Elastosil 2030, Ecoflex 00-30, CF19-2186, and VHB 4905. The results reveal that SRMs demonstrate negligible Mullins effect and hysteresis, while their dielectric strength (62.4‒112.4 V/µm) and viscoelasticity (tan⁡δ 0.07‒0.24 at 10 Hz) are comparable or even superior to those of other elastomers. In addition, elongation at break is found to be 163.8‒172.1%. SRMs exhibit excellent electro-mechanical performance; for instance, one of the two types has an actuation force 293.2 mN at 24.9 V/µm and a strain of 5.2% at 22.3 V/µm. These values are the largest or larger than most of the tested elastomers. The high performance of SRMs results from their dielectric constant, which ranges from 10.3‒13.4, leading to an electro-mechanical sensitivity of up to 15.3 MPa-1. These results illustrate SRMs as attractive material options for DEAs.

A Robust Multilayer Dielectric Elastomer Actuator

2015 ◽  
Vol 1718 ◽  
pp. 145-155
Author(s):  
Mason A. Wolak ◽  
Lei Zhu
Keyword(s):  
Vinylidene Fluoride ◽  
Breakdown Strength ◽  
Electrical Breakdown ◽  
Layer Structure ◽  
Axial Strain ◽  
Dielectric Strength ◽  
Dielectric Elastomer ◽  
Effective Field ◽  
Electromechanical Performance ◽  
Multilayer Dielectric

ABSTRACTWe recently fabricated and characterized a new class of multilayer dielectric elastomer films comprising alternating layers of two different polymers, at least one of which is an elastomer. The films discussed here contain THV (a terpolymer of poly(vinylidene fluoride)) and poly(ethylene octene) [EO] elastomer. The multilayer structure provides improved dielectric and electromechanical performance relative to monolithic films of THV or EO. These properties are controlled by the composition and the layer structure. For example, increasing the concentration of the elastomeric EO component increases the maximum axial strain (sz). Layering EO with THV also increases the breakdown strength (EB ∼ 265 - 300 V/µm) relative to monolithic EO (EB ∼ 150 V/µm) or THV (EB ∼ 245 V/µm) control films. This enhancement in breakdown strength is consistent with a barrier effect that is also observed in multilayer polymer capacitor films. The increase in breakdown strength allows 512-layer 75 vol% EO / 25 vol% THV films to achieve maximum axial strains of sz nearly 4%, higher than can be attained by either EO or THV films alone. In addition, layering reduces remnant strain and electromechanical hysteresis by limiting the effective field within the THV layers. The 75% EO/ 25% THV films show robust operational longevity with little loss in axial strain when subjected to repeated actuation at Emax = 225 V/µm (producing sz = 2.2%). Under these conditions, we observe 3,000 consecutive actuation cycles with no electrical breakdown. In comparison, single component EO control films undergo electrical breakdown at this field and THV control films survive only a few hundred actuation cycles under these conditions. The results demonstrate that multilayering is an effective technique to increase the dielectric strength of elastomer materials and in turn improve upon strain and operational longevity (repeated actuation cycles) characteristics.

scholarly journals Characterization and Optimization of Elastomeric Electrodes for Dielectric Elastomer Artificial Muscles

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5542
Author(s):  
Guangqiang Ma ◽  
Xiaojun Wu ◽  
Lijin Chen ◽  
Xin Tong ◽  
Weiwei Zhao
Keyword(s):  
High Performance ◽  
Dielectric Elastomer ◽  
Elastomeric Matrix ◽  
Dielectric Elastomer Actuators ◽  
Lower Elongation ◽  
The Cost ◽  
Long Term Performance ◽  
Term Performance ◽  
Conductive Particles ◽  
Compliant Electrodes

Dielectric elastomer actuators (DEAs) are an emerging type of soft actuation technology. As a fundamental unit of a DEA, the characteristics of compliant electrodes play a crucial role in the actuation performances of DEAs. Generally, the compliant electrodes can be categorized into uncured and cured types, of which the cured one commonly involves mixing conductive particles into an elastomeric matrix before curing, thus demonstrating a better long-term performance. Along with the increasing proportion of conductive particles, the electrical conductivity increases at the cost of a stiffer electrode and lower elongation at break ratio. For different DEA applications, it can be more desirable to minimize the electrode stiffness or to maximize its conductivity. In examination of the papers published in recent years, few works have characterized the effects of elastomeric electrodes on the outputs of DEAs, or of their optimizations under different application scenarios. In this work, we propose an experimental framework to characterize the performances of elastomeric electrodes with different formulas based on the two key parameters of stiffness and conductivity. An optimizing method is developed and verified by two different application cases (e.g., quasi-static and dynamic). The findings and the methods developed in this work can offer potential approaches for developing high-performance DEAs.

Conductive stretchable composites properly engineered to develop highly compliant electrodes for dielectric elastomer actuators

2018 ◽  
Vol 27 (10) ◽  
pp. 105005 ◽  
Author(s):  
Adrian Bele ◽  
Codrin Tugui ◽  
Mihai Asandulesa ◽  
Daniela Ionita ◽  
Lavinia Vasiliu ◽  
...  
Keyword(s):  
Dielectric Elastomer ◽  
Dielectric Elastomer Actuators ◽  
Compliant Electrodes
Sign in / Sign up

Export Citation Format

Share Document