Properties of a Dielectric Elastomer Actuator Modified by Dispersion of Functionalised Carbon Nanotubes

2012 ◽  
Vol 79 ◽  
pp. 41-46 ◽  
Author(s):  
Fabia Galantini ◽  
Sabrina Bianchi ◽  
Valter Castelvetro ◽  
Irene Anguillesi ◽  
Giuseppe Gallone
Keyword(s):  
Carbon Nanotubes ◽  
Dielectric Constant ◽  
Mechanical Performance ◽  
Broad Class ◽  
Dielectric Elastomer ◽  
Low Dielectric ◽  
Dielectric Elastomer Actuators ◽  
Electromechanical Transduction ◽  
The Matrix ◽  
Simple Matrix

Among the broad class of electro-active polymers, dielectric elastomer actuators represent a rapidly growing technology for electromechanical transduction. In order to further develop this applied science, the high driving voltages currently needed must be reduced. For this purpose, one of the most promising and adopted approach is to increase the dielectric constant while maintaining both low dielectric losses and high mechanical compliance. In this work, a dielectric elastomer was prepared by dispersing functionalised carbon nanotubes into a polyurethane matrix and the effects of filler dispersion into the matrix were studied in terms of dielectric, mechanical and electro-mechanical performance. An interesting increment of the dielectric constant was observed throughout the collected spectrum while the loss factor remained almost unchanged with respect to the simple matrix, indicating that conductive percolation paths did not arise in such a system. Consequences of the chemical functionalisation of carbon nanotubes with respect to the use of unmodified filler were also studied and discussed along with rising benefits and drawbacks for the whole composite material.

Improved Materials for Dielectric Elastomer Actuators

2008 ◽  
Author(s):  
Dorina Opris ◽  
Martin Molberg ◽  
Christiane Lo¨we ◽  
Frank Nu¨esch ◽  
Christopher Plummer ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Dielectric Constant ◽  
Electroactive Polymers ◽  
Dielectric Elastomer ◽  
Electromechanical Properties ◽  
Silicone Elastomers ◽  
Broad Application ◽  
Dielectric Elastomer Actuators ◽  
Electromechanical Transduction ◽  
Doped Polyaniline

Dielectric elastomers are an emerging class of electroactive polymers for electromechanical transduction. A broad application of dielectric elastomer actuators (DEA) is limited by the high voltage necessary to drive such devices. The development of novel elastomers offering better intrinsic electromechanical properties is one way to solve the problem. Therefore we prepared composites from thermoplastic or thermoset silicone elastomers and organic fillers as phthalocyanines or doped polyaniline (PANI). We studied the mechanical properties of silicones, synthesized, modified and characterized phthalocyanines and doped PANI. The influence of humidity onto the dielectric properties of CuPc(COOH)8 and ZnPc(COOH)8 was analyzed in detail. First measurements of silicone/PANI blends results in a hundredfold increase for the dielectric constant and an electromechanically strain of 8.5%.

High Breakdown Field Dielectric Elastomer Actuators Using Encapsulated Polyaniline as High Dielectric Constant Filler

2010 ◽  
Vol 20 (19) ◽  
pp. 3280-3291 ◽  
Author(s):  
Martin Molberg ◽  
Daniel Crespy ◽  
Patrick Rupper ◽  
Frank Nüesch ◽  
Jan-Anders E. Månson ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
High Dielectric Constant ◽  
Dielectric Elastomer ◽  
Breakdown Field ◽  
Dielectric Elastomer Actuators ◽  
High Dielectric

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

Soft Matter ◽  
2017 ◽  
Vol 13 (37) ◽  
pp. 6390-6395 ◽  
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.

An MRI-Compatible Needle Manipulator Concept Based on Elastically Averaged Dielectric Elastomer Actuators for Prostate Cancer Treatment: An Accuracy and MR-Compatibility Evaluation in Phantoms

2009 ◽  
Vol 3 (3) ◽  
Author(s):  
Jean-Sébastien Plante ◽  
Kenjiro Tadakuma ◽  
Lauren M. DeVita ◽  
Daniel F. Kacher ◽  
Joseph R. Roebuck ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Parallel Manipulator ◽  
Mechanical Performance ◽  
Low Cost ◽  
Dielectric Elastomer ◽  
Polymer Actuators ◽  
Dielectric Elastomer Actuators ◽  
Viable Approach ◽  
Cancer Biopsy ◽  
Prostate Cancer Treatments

A parallel manipulator concept using bistable polymer actuators has been developed to perform prostate cancer biopsy, and deliver therapy within the bore of a magnetic resonance imaging (MRI) scanner. The dielectric elastomer actuators (DEAs) used in this manipulator concept are promising for MRI-compatible robotics because they do not interfere with the high magnetic fields of MRI while having good mechanical performance and being low cost. In the past, these actuators have been plagued by robustness problems when used in a continuous manner. Recent studies show that reliability significantly improves when DEAs are used in a bistable manner, as proposed here. This paper investigates the potential of the proposed manipulator concept by evaluating the positioning accuracy and MRI compatibility of a laboratory prototype, developed for clinically relevant design criteria. An analytical model of the manipulator kinematics is presented. Analytical and experimental results validate that the proposed technology can provide an accurate needle placement required to perform prostate cancer treatments. The prototype’s MRI compatibility is validated in a 3 T clinical MRI scanner. The parallel manipulator concept using bistable polymer actuators is shown to be a viable approach to perform MRI-guided needle insertions for prostate cancer biopsy and therapy.

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.

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.

Synthesis and Characterization of Polymer Nanofoams

2007 ◽  
Vol 334-335 ◽  
pp. 821-824 ◽  
Author(s):  
Yi He Zhang ◽  
Y. Li ◽  
Hai Tao Huang ◽  
Sha Ming Ke ◽  
Li Hang Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Dielectric Constant ◽  
Polyimide Film ◽  
Dielectric Constants ◽  
Low Dielectric ◽  
The Matrix ◽  
Poly Ethylene ◽  
Polyimide Matrix ◽  
A Minor ◽  
Film Dielectric

In order to obtain thin film dielectric layers with very low dielectric constants for use in microelectronic devices, polyimide nanofoamed films has been prepared from the polyimide precursors (PMDA-ODA) and poly(ethylene oxide) (PEO) in N,N-dimethylacetamide. The synthesization process included blending polyimide as the major phase with a minor phase of the thermally labile PEO blocks. The foamed films were characterized by a variety of experiments including TG and SEM, and the experimental results indicated that the labile PEO would undergo oxidative thermolysis to release small moleculars from the matrix so as to leave voids into the polyimide matrix. The dielectric properties of the films were studied over broad frequency ranges. The dependences of dielectric constant on the PEO content in the films and frequency were discussed. The films with a proper amount of PEO displayed relatively low dielectric constant compared to the pure polyimide film. Thin film foams with high thermal stability and low dielectric constants can be prepared using the approach.

scholarly journals Modified halloysite nanotube filled polyimide composites for film capacitors: high dielectric constant, low dielectric loss and excellent heat resistance

RSC Advances ◽  
2018 ◽  
Vol 8 (19) ◽  
pp. 10522-10531 ◽  
Author(s):  
Tianwen Zhu ◽  
Chao Qian ◽  
Weiwen Zheng ◽  
Runxin Bei ◽  
Siwei Liu ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
High Dielectric Constant ◽  
Halloysite Nanotubes ◽  
Halloysite Nanotube ◽  
Low Dielectric ◽  
The Matrix ◽  
Polyimide Composites ◽  
High Dielectric

Halloysite nanotubes (HNTs) were chosen as the fillers and polyimide (PI) as the matrix to form a series of composites with excellent dielectric properties and thermostabilities.

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