Trajectory control and random vibration control of nonlinear system with dielectric elastomer actuator

Dielectric elastomer actuators have gained extensive attention in scientific and industrial communities with the rapid development of soft robot technology. There still remain some questions on the control aspect of nonlinear system with dielectric elastomer actuator. The first is whether the soft actuator can successfully drive the primary structure to track an arbitrary prescribed trajectory. The second is how to suppress the random vibration around the equilibrium position when the primary structure is disturbed by external excitation. This article seeks the answers for these two questions. By directly solving the governing equation of motion, an open-loop control technique is designed to track a prescribed trajectory. The effectiveness of the trajectory tracking technique is investigated and the limitation is illustrated by the influence of inertia of the primary structure. Based on the stochastic averaging of energy envelope and stochastic dynamic programming principle, a clipped control strategy is proposed by slightly adjusting the voltage in real time to suppress the random vibration around the equilibrium position. The good effectiveness and high robustness of the clipped control strategy are verified numerically. This work may provide some guidelines for the control aspect of nonlinear systems with dielectric elastomer actuators.

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Highly flexible and transparent dielectric elastomer actuators using silver nanowire and carbon nanotube hybrid electrodes

Soft Matter ◽

10.1039/c7sm01329a ◽

2017 ◽

Vol 13 (37) ◽

pp. 6390-6395 ◽

Cited By ~ 17

Author(s):

Ye Rim Lee ◽

Hyungho Kwon ◽

Do Hoon Lee ◽

Byung Yang Lee

Keyword(s):

Carbon Nanotubes ◽

Carbon Nanotube ◽

Silver Nanowires ◽

Dielectric Elastomer ◽

Silver Nanowire ◽

Dielectric Elastomer Actuator ◽

Dielectric Elastomer Actuators ◽

Transparent Dielectric ◽

Optically Transparent ◽

Highly Stretchable

Electrodes consisting of silver nanowires and carbon nanotubes enable a dielectric elastomer actuator to become highly stretchable and optically transparent.

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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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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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Dielectric Elastomer Actuators with Carbon Nanotube Electrodes Painted with a Soft Brush

Actuators ◽

10.3390/act7030051 ◽

2018 ◽

Vol 7 (3) ◽

pp. 51 ◽

Cited By ~ 11

Author(s):

Hiroki Shigemune ◽

Shigeki Sugano ◽

Jun Nishitani ◽

Masayuki Yamauchi ◽

Naoki Hosoya ◽

...

Keyword(s):

Carbon Nanotube ◽

Electronic Properties ◽

Large Deformation ◽

Dielectric Elastomer ◽

Dielectric Elastomer Actuator ◽

Dielectric Elastomer Actuators ◽

Multiple Trials

We propose a simple methodology to paint carbon nanotube (CNT) powder with a soft brush onto an elastomer. A large deformation of dielectric elastomer actuator (DEA) occurs according to the small constraint of the electrodes. Uniform painting with a soft brush leads to a stable deformation, as demonstrated by the results of multiple trials. Unexpectedly, painting with a soft brush results in aligned materials on the elastomer. The oriented materials demonstrate anisotropic mechanical and electronic properties. This simple methodology should help realize innovative DEA applications.

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On the improvement of the dynamic performance of dielectric elastomer actuators for active compression

Journal of Intelligent Material Systems and Structures ◽

10.1177/1045389x18754348 ◽

2018 ◽

Vol 29 (5) ◽

pp. 986-997 ◽

Cited By ~ 1

Author(s):

Hamza Edher ◽

Armaghan Salehian

Keyword(s):

Dynamic Performance ◽

Hold Time ◽

Compressive Force ◽

Dielectric Elastomer ◽

Output Curve ◽

Dielectric Elastomer Actuator ◽

Dielectric Elastomer Actuators ◽

Low Weight ◽

Output Force ◽

Novel Method

Dielectric elastomer actuators have been considered for an increasing number of applications due to their desirable characteristics of low weight, high strain outputs and favourable material costs. The present work describes the use of a dielectric elastomer actuator in conjunction with a belt mechanism to apply cyclic active compression. The belt mechanism helps convert the stress relaxation upon the voltage application to the dielectric elastomer actuator to a compressive force. Testing is conducted using multi-layered silicone–based dielectric elastomer actuators. A novel method of dynamically charging dielectric elastomer actuators through manipulating the input signal shape, termed the hold method, is introduced. Using this method, cyclic actuation strain output can be increased by 24% with insignificant change in actuation output curve shape. Furthermore, the effect of pre-stretch ratios on the output force amplitudes is characterized. The optimized hold time parameters obtained through cyclic dielectric elastomer force and strain are utilized for active compression physiological testing and a pressure gradient of 10 mmHg is achieved.

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