Dielectric Elastomer Fiber Actuators with Aqueous Electrode

Dielectric elastomer actuators (DEAs) are one of the promising actuation technologies for soft robotics. This study proposes a fiber-shaped DEA, namely dielectric elastomer fiber actuators (DEFAs). The actuator consisted of a silicone tube filled with the aqueous electrode (sodium chloride solution). Furthermore, it could generate linear and bending actuation in a water environment, which acts as the ground side electrode. Linear-type DEFA and bending-type DEFA were fabricated and characterized to prove the concept. A mixture of Ecoflex 00–30 (Smooth-On) and Sylgard 184 (Dow Corning) was employed in these actuators for the tube part, which was 75.0-mm long with outer and inner diameters of 6.0 mm and 5.0 mm, respectively. An analytical model was constructed to design and predict the behavior of the devices. In the experiments, the linear-type DEFA exhibited an actuation strain and force of 1.3% and 42.4 mN, respectively, at 10 kV (~20 V/µm) with a response time of 0.2 s. The bending-type DEFA exhibited an actuation angle of 8.1° at 10 kV (~20 V/µm). Subsequently, a jellyfish-type robot was developed and tested, which showed the swimming speed of 3.1 mm/s at 10 kV and the driving frequency of 4 Hz. The results obtained in this study show the successful implementation of the actuator concept and demonstrate its applicability for soft robotics.

Download Full-text

Dielectric Elastomer Grippers

International Journal of Engineering and Advanced Technology - Regular Issue ◽

10.35940/ijeat.e2548.0610521 ◽

2021 ◽

Vol 10 (5) ◽

pp. 33-36

Author(s):

Mills Patel ◽

Rudrax Khamar ◽

Akshat Shah ◽

Tej shah ◽

Bhavik Soneji

Keyword(s):

Mechanical Properties ◽

Power Generation ◽

State Of The Art ◽

Artificial Muscle ◽

Dielectric Elastomer ◽

Soft Robotics ◽

Artificial Muscles ◽

Dielectric Elastomer Actuators ◽

Working Principle ◽

Soft Actuators

This paper appraisals state-of-the-art dielectric elastomer actuators (DEAs) and their forthcoming standpoints as soft actuators which have freshly been considered as a crucial power generation module for soft robots. DEs behave as yielding capacitors, expanding in area and attenuation in thickness when a voltage is applied. The paper initiates with the explanation of working principle of dielectric elastomer grippers. Here the operation of DEAs include both physics and mechanical properties with its characteristics, we have describe methods for modelling and its introductory application. In inclusion, the artificial muscle based on DEA concept is also formally presented. This paper also elaborates DEAs popular application such as- Soft Robotics, Robotics grippers and artificial muscles.

Download Full-text

Soft Robotic Gripper Based on Multi-Layers of Dielectric Elastomer Actuators

Journal of Robotics and Mechatronics ◽

10.20965/jrm.2021.p0968 ◽

2021 ◽

Vol 33 (4) ◽

pp. 968-974

Author(s):

Witchuda Thongking ◽

Ardi Wiranata ◽

Ayato Minaminosono ◽

Zebing Mao ◽

Shingo Maeda ◽

...

Keyword(s):

Response Time ◽

Low Cost ◽

Fast Response ◽

Dielectric Elastomer ◽

Heel Strike ◽

Soft Robotics ◽

Artificial Muscles ◽

Light Weight ◽

Dielectric Elastomer Actuators ◽

The Relationship

Dielectric elastomer actuators (DEAs) are a promising technology for soft robotics. The use of DEAs has many advantages, including light weight, resilience, and fast response for its applications, such as grippers, artificial muscles, and heel strike generators. Grippers are commonly used as grasping devices. In this study, we focus on DEA applications and propose a technology to expand the applicability of a soft gripper. The advantages of gripper-based DEAs include light weight, fast response, and low cost. We fabricated soft grippers using multiple DEA layers. The grippers successfully held or gripped an object, and we investigated the response time of the grippers and their angle characteristics. We studied the relationship between the number of DEA layers and the performance of our grippers. Our experimental results show that the multi-layered DEAs have the potential to be strong grippers.

Download Full-text

Linear-Quadratic Regulator for Control of Multi-Wall Carbon Nanotube/Polydimethylsiloxane Based Conical Dielectric Elastomer Actuators

Actuators ◽

10.3390/act9010018 ◽

2020 ◽

Vol 9 (1) ◽

pp. 18

Author(s):

Titus Mulembo ◽

Waweru Njeri ◽

Gakuji Nagai ◽

Hirohisa Tamagawa ◽

Keishi Naito ◽

...

Keyword(s):

Carbon Nanotube ◽

Rise Time ◽

Electromechanical Coupling ◽

Linear Quadratic Regulator ◽

Fast Response ◽

Dielectric Elastomer ◽

Soft Robotics ◽

Artificial Muscles ◽

Linear Quadratic ◽

Dielectric Elastomer Actuators

Conventional rigid actuators, such as DC servo motors, face challenges in utilizing them in artificial muscles and soft robotics. Dielectric elastomer actuators (DEAs) overcome all these limitations, as they exhibit complex and fast motions, quietness, lightness, and softness. Recently, there has been much focus on studies of the DEAs material’s non-linearity, the non-linear electromechanical coupling, and viscoelastic behavior of VHB and silicone-based conical DEAs having compliant electrodes that are based on graphite powder and carbon grease. However, the mitigation of overshoot that arises from fast response conical DEAs made with solid electrodes has not received much research focus. In this paper, we fabricated a conical configuration of multi-walled carbon nanotube/polydimethylsiloxane (MWCNT/PDMS) based DEAs with a rise time of 10 ms, and 50% peak overshoot. We developed a full feedback state-based linear-quadratic regulator (LQR) having Luenberger observer to mitigate the DEAs overshoot in both the voltage ON and OFF instances. The cone DEA’s model was identified and a stable and well-fitting transfer function with a fit of 94% was obtained. Optimal parameters Q = 70,000, R = 0.1, and Q = 7000, R = 0.01 resulted in the DEA response having a rise time value of 20 ms with zero overshoot, in both simulations and experiments. The LQR approach can be useful for the control of fast response DEAs and this would expand the potential use of the DEAs as artificial muscles in soft robotics.

Download Full-text

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

Royal Society Open Science ◽

10.1098/rsos.182145 ◽

2019 ◽

Vol 6 (8) ◽

pp. 182145 ◽

Cited By ~ 1

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.

Download Full-text

Monolithic Stacked Dielectric Elastomer Actuators

Frontiers in Robotics and AI ◽

10.3389/frobt.2021.714332 ◽

2021 ◽

Vol 8 ◽

Author(s):

Jun Shintake ◽

Daiki Ichige ◽

Ryo Kanno ◽

Toshiaki Nagai ◽

Keita Shimizu

Keyword(s):

Three Dimensional ◽

Dielectric Elastomer ◽

Free Form ◽

Microfluidic Channels ◽

Successful Implementation ◽

Elastomeric Matrix ◽

Dielectric Elastomer Actuators ◽

Multiple Electrodes ◽

Output Force

Dielectric elastomer actuators (DEAs) are a promising actuator technology for soft robotics. As a configuration of this technology, stacked DEAs afford a muscle-like contraction that is useful to build soft robotic systems. In stacked DEAs, dielectric and electrode layers are alternately stacked. Thus, often a dedicated setup with complicated processes or sometimes laborious manual stacking of the layers is required to fabricate stacked actuators. In this study, we propose a method to monolithically fabricate stacked DEAs without alternately stacking the dielectric and electrode layers. In this method, the actuators are fabricated mainly through two steps: 1) molding of an elastomeric matrix containing free-form microfluidic channels and 2) injection of a liquid conductive material that acts as an electrode. The feasibility of our method is investigated via the fabrication and characterization of simple monolithic DEAs with multiple electrodes (2, 4, and 10). The fabricated actuators are characterized in terms of actuation stroke, output force, and frequency response. In the actuators, polydimethylsiloxane (PDMS) and eutectic gallium–indium (EGaIn) are used for the elastomeric matrix and electrode material, respectively. Microfluidic channels are realized by dissolving a three-dimensional printed part suspended in the elastomeric structure. The experimental results show the successful implementation of the proposed method and the good agreement between the measured data and theoretical predication, validating the feasibility of the proposed method.

Download Full-text

Printing 3D dielectric elastomer actuators for soft robotics

10.1117/12.815746 ◽

2009 ◽

Cited By ~ 47

Author(s):

Jonathan Rossiter ◽

Peter Walters ◽

Boyko Stoimenov

Keyword(s):

Dielectric Elastomer ◽

Soft Robotics ◽

Dielectric Elastomer Actuators

Download Full-text

A Co-Axial Dielectric Elastomer Actuator

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.61.81 ◽

2008 ◽

Vol 61 ◽

pp. 81-84 ◽

Cited By ~ 8

Author(s):

Hristiyan Stoyanov ◽

Guggi Kofod ◽

Reimund Gerhard

Keyword(s):

High Energy ◽

Dip Coating ◽

Dielectric Elastomer ◽

Thin Layers ◽

High Energy Density ◽

Dielectric Elastomer Actuator ◽

Dielectric Elastomer Actuators ◽

Active Layers ◽

Potential Applications ◽

Actuation Strain

Dielectric elastomer actuators based on Maxwell-stress induced deformation, are considered for many potential applications where high actuation strain and high energy density are required. They usually rely on a planar actuator configuration, however, a string-like actuator would be less bulky, and more versatile for several applications. In this paper, a co-axial dielectric elastomer actuator that produces relatively high actuation strain is presented. The actuator is manufactured through alternating dip-coating steps with insulating and conductive thin layers. A soluble thermoplastic block-copolymer, SEBS(poly-(styrene-ethylene-butylene-styrene), is used for the dielectric layers as well as for the host material of the compliant electrodes. Electrical conductivity of the electrodes is achieved by incorporation of conductive carbon-black particles in the elastomer matrix. Actuators with a single and with multiple active layers (up to three) have been successfully demonstrated. This geometry is advantageous in that it is compact and can be bundled easily, and should therefore be practical in applications such as “artificial muscles”.

Download Full-text

Broadening the Actuation Temperature Range for Acrylic Dielectric Elastomers

Volume 1: Active Materials, Mechanics and Behavior; Modeling, Simulation and Control ◽

10.1115/smasis2009-1438 ◽

2009 ◽

Author(s):

Antony Jan ◽

Wei Yuan ◽

Paul Brochu ◽

Han Zhang ◽

Qibing Pei ◽

...

Keyword(s):

Glass Transition ◽

Transition Temperature ◽

Glass Transition Temperature ◽

Room Temperature ◽

Dielectric Elastomer ◽

Temperature Range ◽

Dielectric Elastomer Actuators ◽

Soft Polymer ◽

Important Branch ◽

Actuation Strain

Dielectric elastomer actuators are an important branch of electroactive polymers with a host of applications proposed. However, the temperature range over which these elastomers are active has been limited by the glass transition temperature and thermal stability. Acrylic elastomers, VHB adhesive films from 3M Company, exhibit high actuation strain and stress at room temperature, but become too rigid to actuate below 0 °C. By lowering their glass transition temperature with the addition of a plasticizer, we show that the soft polymer actuators can be made to function at −40 °C. The plasticized films have been able to achieve >100% areal strain at −40°C. This helps extend the scope of dielectric elastomer actuators to demanding automotive applications.

Download Full-text