Significant improvements in the electromechanical performance of dielectric elastomers by introducing ternary dipolar groups

2022 ◽  
pp. 105177
Author(s):  
Leipeng Liu ◽  
Kangning Zhang ◽  
Jinru Liu ◽  
Lei Zhu ◽  
Ruiying Xie ◽  
...  
Keyword(s):  
Dielectric Elastomers ◽  
Electromechanical Performance

DESIGNING DIELECTRIC ELASTOMERS OVER MULTIPLE LENGTH SCALES FOR 21ST CENTURY SOFT MATERIALS TECHNOLOGIES

2017 ◽  
Vol 90 (2) ◽  
pp. 207-224 ◽  
Author(s):  
Daniel P. Armstrong ◽  
Richard J. Spontak
Keyword(s):  
Electric Fields ◽  
Thermoplastic Elastomer ◽  
Soft Materials ◽  
Dielectric Elastomers ◽  
Length Scales ◽  
Electric Stimulus ◽  
Profound Impact ◽  
Multiple Length Scales ◽  
Electromechanical Performance ◽  
Strain Cycling

ABSTRACT Dielectric elastomers (DEs) constitute an increasingly important category of electroactive polymers. They are in a class of generally soft materials that, upon exposure to an electric stimulus, respond by changing size, shape, or both. Derived from network-forming macromolecules, DEs are lightweight, robust and scalable, and they are capable of exhibiting giant electroactuation strains, high electromechanical efficiencies, and relatively low strain-cycling hysteresis over a broad range of electric fields. Due primarily to their attractive electromechanical attributes, DEs are of growing interest in diverse biomedical, (micro)robotic, and analytical technologies. Since the seminal studies of these electroresponsive materials (initially fabricated mainly from chemically cross-linked acrylic and silicone elastomers), advances in materials design over multiple length scales have resulted in not only improved electromechanical performance but also better mechanistic understanding. We first review the fundamental operating principles of DEs developed from conventional elastomers that undergo isotropic electroactuation and then consider more recent advances at different length scales. At the macroscale, incorporation of oriented fibers within elastomeric matrices is found to have a profound impact on electroactuation by promoting an anisotropic response. At the mesoscale, physically cross-linked thermoplastic elastomer gel networks formed by midblock-swollen triblock copolymers provide a highly tunable alternative to chemically cross-linked elastomers. At the nanoscale, the chemical synthesis of binetwork and bottlebrush elastomers permits extraordinarily enhanced electromechanical performance through targeted integration of inherently prestrained macromolecular networks.

A Finite Element Method for Dielectric Elastomers Affected by Viscoelasticity and Current Leakage

2018 ◽  
Vol 10 (09) ◽  
pp. 1850102 ◽  
Author(s):  
Choon Chiang Foo ◽  
Jun Liu ◽  
Zhi-Qian Zhang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Large Deformation ◽  
Constitutive Theory ◽  
Dielectric Elastomers ◽  
Simulation Platform ◽  
Current Leakage ◽  
Dissipative Processes ◽  
Finite Element Implementation ◽  
Electromechanical Performance

Dissipative processes such as viscoelasticity and current leakage are known to affect the electromechanical performance of dielectric elastomers. In this work, we describe a constitutive theory that couples electrostatics, large deformation, viscoelasticity and current leakage. We also implement this model in a commercial finite element solver ABAQUS by developing new user-defined elements. The method is used to study the effect of viscoelasticity and current leakage on the behavior of dielectric elastomers. Our finite element implementation will serve as a simulation platform to guide the design of practical dielectric elastomer transducers.

Electromechanical Performance of Viscoelastic Dielectric Elastomer Actuator Undergoing Temperature Variation

2015 ◽  
Author(s):  
Junjie Sheng ◽  
Shuyong Li ◽  
Yuqing Zhang ◽  
Lei Liu
Keyword(s):  
Temperature Variation ◽  
Conversion Efficiency ◽  
Experimental Results ◽  
Time Dependent ◽  
Effect Of Temperature ◽  
Dielectric Elastomers ◽  
Dielectric Elastomer Actuator ◽  
Viscoelastic Creep ◽  
Electromechanical Performance ◽  
Higher Temperature

Viscoelasticity causes a time-dependent performance and affects the conversion efficiency of VHB-based dielectric elastomers actuator (DEA), when subject to voltage and temperature. However, few reports focus on the effect of temperature on the viscoelastic electromechanical performance on the DEA. The viscoelastic performance of a VHB film in a circular actuator configuration undergoing temperature variation is studied both theoretically and experimentally. Subjected to temperature variation and voltage, viscoelastic creep and higher deformation at higher temperature are obtained using thermodynamics models. Subsequently, an experiment was designed to validate the simulation and the results indicate that DEA creeps with time due to the viscoelasticity and a bigger deformation can be achieved at a higher temperature, which shows well consistent with the experimental results.

Improving the electromechanical performance of dielectric elastomers using silicone rubber and dopamine coated barium titanate

2015 ◽  
Vol 85 ◽  
pp. 733-742 ◽  
Author(s):  
Liang Jiang ◽  
Anthony Betts ◽  
David Kennedy ◽  
Stephen Jerrams
Keyword(s):  
Barium Titanate ◽  
Silicone Rubber ◽  
Dielectric Elastomers ◽  
Electromechanical Performance

Significantly improved electromechanical performance of dielectric elastomers via alkyl side-chain engineering

2017 ◽  
Vol 5 (27) ◽  
pp. 6834-6841 ◽  
Author(s):  
Jie Mao ◽  
Tiefeng Li ◽  
Yingwu Luo
Keyword(s):  
Electric Field ◽  
Side Chain ◽  
Dielectric Elastomers ◽  
Alkyl Side Chain ◽  
Electromechanical Performance

Dielectric elastomers (DEs) can be deformed in response to an electric field.

scholarly journals Complex Geometry Strain Sensors Based on 3D Printed Nanocomposites: Spring, Three-Column Device and Footstep-Sensing Platform

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1106
Author(s):  
Alejandro Cortés ◽  
Xoan F. Sánchez-Romate ◽  
Alberto Jiménez-Suárez ◽  
Mónica Campo ◽  
Ali Esmaeili ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
3D Printing ◽  
Complex Geometry ◽  
Uv Light ◽  
Shielding Effect ◽  
Strain Sensitivity ◽  
Printing Technology ◽  
3D Printing Technology ◽  
Sensing Platform ◽  
Electromechanical Performance

Electromechanical sensing devices, based on resins doped with carbon nanotubes, were developed by digital light processing (DLP) 3D printing technology in order to increase design freedom and identify new future and innovative applications. The analysis of electromechanical properties was carried out on specific sensors manufactured by DLP 3D printing technology with complex geometries: a spring, a three-column device and a footstep-sensing platform based on the three-column device. All of them show a great sensitivity of the measured electrical resistance to the applied load and high cyclic reproducibility, demonstrating their versatility and applicability to be implemented in numerous items in our daily lives or in industrial devices. Different types of carbon nanotubes—single-walled, double-walled and multi-walled CNTs (SWCNTs, DWCNTs, MWCNTs)—were used to evaluate the effect of their morphology on electrical and electromechanical performance. SWCNT- and DWCNT-doped nanocomposites presented a higher Tg compared with MWCNT-doped nanocomposites due to a lower UV light shielding effect. This phenomenon also justifies the decrease of nanocomposite Tg with the increase of CNT content in every case. The electromechanical analysis reveals that SWCNT- and DWCNT-doped nanocomposites show a higher electromechanical performance than nanocomposites doped with MWCNTs, with a slight increment of strain sensitivity in tensile conditions, but also a significant strain sensitivity gain at bending conditions.

scholarly journals Supramolecular ionic polymer/carbon nanotube composite hydrogels with enhanced electromechanical performance

2020 ◽  
Vol 9 (1) ◽  
pp. 478-488 ◽  
Author(s):  
Yun-Fei Zhang ◽  
Fei-Peng Du ◽  
Ling Chen ◽  
Ka-Wai Yeung ◽  
Yuqing Dong ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Ion Mobility ◽  
Artificial Muscles ◽  
Ionic Polymer ◽  
Composite Hydrogels ◽  
The Matrix ◽  
Electromechanical Performance ◽  
Carbon Nanotube Composite ◽  
Robotic Devices

AbstractElectroactive hydrogels have received increasing attention due to the possibility of being used in biomimetics, such as for soft robotics and artificial muscles. However, the applications are hindered by the poor mechanical properties and slow response time. To address these issues, in this study, supramolecular ionic polymer–carbon nanotube (SIPC) composite hydrogels were fabricated via in situ free radical polymerization. The polymer matrix consisted of carbon nanotubes (CNTs), styrene sulfonic sodium (SSNa), β-cyclodextrin (β-CD)-grafted acrylamide, and ferrocene (Fc)-grafted acrylamide, with the incorporation of SSNa serving as the ionic source. On applying an external voltage, the ions accumulate on one side of the matrix, leading to localized swelling and bending of the structure. Therefore, a controllable and reversible actuation can be achieved by changing the applied voltage. The tensile strength of the SIPC was improved by over 300%, from 12 to 49 kPa, due to the reinforcement effect of the CNTs and the supramolecular host–guest interactions between the β-CD and Fc moieties. The inclusion of CNTs not only improved the tensile properties but also enhanced the ion mobility, which lead to a faster electromechanical response. The presented electro-responsive composite hydrogel shows a high potential for the development of robotic devices and soft smart components for sensing and actuating applications.

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