Cell Nanomechanics Based on Dielectric Elastomer Actuator Device

Abstract As a frontier of biology, mechanobiology plays an important role in tissue and biomedical engineering. It is a common sense that mechanical cues under extracellular microenvironment affect a lot in regulating the behaviors of cells such as proliferation and gene expression, etc. In such an interdisciplinary field, engineering methods like the pneumatic and motor-driven devices have been employed for years. Nevertheless, such techniques usually rely on complex structures, which cost much but not so easy to control. Dielectric elastomer actuators (DEAs) are well known as a kind of soft actuation technology, and their research prospect in biomechanical field is gradually concerned due to their properties just like large deformation (> 100%) and fast response (< 1 ms). In addition, DEAs are usually optically transparent and can be fabricated into small volume, which make them easy to cooperate with regular microscope to realize real-time dynamic imaging of cells. This paper first reviews the basic components, principle, and evaluation of DEAs and then overview some corresponding applications of DEAs for cellular mechanobiology research. We also provide a comparison between DEA-based bioreactors and current custom-built devices and share some opinions about their potential applications in the future according to widely reported results via other methods.

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Dielectric Elastomer Actuator for Soft Robotics Applications and Challenges

Applied Sciences ◽

10.3390/app10020640 ◽

2020 ◽

Vol 10 (2) ◽

pp. 640 ◽

Cited By ~ 11

Author(s):

Jung-Hwan Youn ◽

Seung Mo Jeong ◽

Geonwoo Hwang ◽

Hyunwoo Kim ◽

Kyujin Hyeon ◽

...

Keyword(s):

State Of The Art ◽

Dielectric Elastomer ◽

Artificial Muscles ◽

Soft Robot ◽

Optical Components ◽

Dielectric Characteristics ◽

Dielectric Elastomer Actuators ◽

Potential Applications ◽

Working Principle ◽

Soft Actuators

This paper reviews state-of-the-art dielectric elastomer actuators (DEAs) and their future perspectives as soft actuators which have recently been considered as a key power generation component for soft robots. This paper begins with the introduction of the working principle of the dielectric elastomer actuators. Because the operation of DEA includes the physics of both mechanical viscoelastic properties and dielectric characteristics, we describe theoretical modeling methods for the DEA before introducing applications. In addition, the design of artificial muscles based on DEA is also introduced. This paper reviews four popular subjects for the application of DEA: soft robot hand, locomotion robots, wearable devices, and tunable optical components. Other potential applications and challenging issues are described in the conclusion.

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Modeling and Actuation Performance Analysis of Conically-Shaped Dielectric Electroactive Polymer Actuator

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.633-634.250 ◽

2014 ◽

Vol 633-634 ◽

pp. 250-256

Author(s):

Yin Long Zhu ◽

Hong Pin Zhou ◽

Hua Ming Wang

Keyword(s):

Dielectric Elastomer ◽

Force Output ◽

Energy Potential ◽

Principal Stresses ◽

Dielectric Elastomer Actuator ◽

Design And Optimization ◽

Dielectric Elastomer Actuators ◽

Proposed Model ◽

Polymer Actuator ◽

Potential Applications

Dielectric elastomer actuators (DEAs) represent one class of electroactive polymers that have already demonstrated excellent performances and show potential applications in many fields. In this paper, we present a simplified conically-shaped dielectric elastomer actuator model to explore the effects of various preloads and actuation voltages on both the actuation displacement and force output of DEA. The strain energy potential of Yeoh is used and the viscoelasticity is also taken into account. Using the developed model, the numerical results of DEA including the actuation displacement, the distribution of the principal stretch ratios and principal stresses in the membrane and the force output can be obtained. With different preloads and actuation voltages, the actuation characteristic of conically-shaped dielectric elastomer actuator is explored experimentally and validates the results determined from the proposed model. The proposed model can be used for the design and optimization of conically-shaped dielectric elastomer actuator.

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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.

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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.

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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”.

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Enhancing dynamic actuation performance of dielectric elastomer actuators by tuning viscoelastic effects with polar crosslinking

NPG Asia Materials ◽

10.1038/s41427-019-0147-5 ◽

2019 ◽

Vol 11 (1) ◽

Cited By ~ 7

Author(s):

Matthew Wei Ming Tan ◽

Gurunathan Thangavel ◽

Pooi See Lee

Keyword(s):

Fast Response ◽

Dielectric Elastomer ◽

Buckling Mode ◽

Polyethylene Glycol Diacrylate ◽

Glycol Diacrylate ◽

Dielectric Elastomer Actuators ◽

Polyurethane Acrylate ◽

Out Of Plane ◽

Viscoelastic Effects ◽

Chemical Crosslinks

Abstract Dielectric elastomer actuators (DEAs) have shown great potential in the field of robotics, energy harvesting, or haptics for wearables. However, existing DEA materials typically require prestretching and exhibit time-dependent deformations due to their inherent viscoelastic properties. In this work, we address these issues by designing and synthesizing a polyurethane acrylate (PUA) DEA copolymerized with a polar crosslinker, polyethylene glycol diacrylate (PEGDA), to reduce viscoelastic effects through chemical crosslinking. We realized a buckling-mode actuator that displays out-of-plane deformations triggered by an electric field without the need for prestretching. Copolymerization with PEGDA showed improved dynamic response actuation performances compared to pristine PUA, wherein the former reached 90% of its maximum actuation in <1 s. In addition, precise and stable actuation was achieved, reducing viscoelastic drifts to a negligible amount. Despite the higher elastic modulus of the DEA incurred by the chemical crosslinks, the polar groups present in the PEGDA comonomer effectively increased the dielectric constant. As such, a higher area strain was achieved in comparison to that exhibited by low viscoelastic elastomers such as silicone. By eliminating the need for prestretching, rigid components can be avoided, thereby enabling greater prospects for the integration of fast response and stable DEAs into soft bodies.

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