Polar–nonpolar interconnected elastic networks with increased permittivity and high breakdown fields for dielectric elastomer transducers

Racleş, Carmen; Bele, Adrian; Dascălu, Mihaela; Musteata, Valentina-Elena; Varganici, Cristian–Dragos; Ionita, Daniela; Vlad, Stelian; Cazacu, Maria; Dünki, Simon J.; Opris, Dorina M.

doi:10.1039/c5ra06865g

Cited by 34 publications

(34 citation statements)

References 38 publications

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“…Favorable results were obtained when mixtures of the cyanopropyl‐functional PDMS and a PDMS pre‐polymer were used to form elastomers (Table ). In a further development with cyanopropyl‐functional materials, (see Figure ) a permittivity of ε' = 4.5 and a breakdown strength of 56 V μm −1 were achieved, while a 13‐times higher actuation strain compared to silicone was also obtained.…”

Section: Investigated Silicone Materials For Dielectric Elastomersmentioning

confidence: 97%

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The Current State of Silicone-Based Dielectric Elastomer Transducers

Madsen

Daugaard

Hvilsted

et al. 2016

Macromol. Rapid Commun.

369

392

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Silicone elastomers are promising materials for dielectric elastomer transducers (DETs) due to superior properties such as high efficiency, reliability and fast response times. DETs consist of thin elastomer films sandwiched between compliant electrodes, and they constitute an interesting class of transducer due to their inherent lightweight and potentially large strains. For the field to progress towards industrial implementation, a leap in material development is required, specifically targeting longer lifetime and higher energy densities to provide more efficient transduction at lower driving voltages. In this review the current state of silicone elastomers for DETs is summarised and critically discussed, including commercial elastomers, composites, polymer blends, grafted elastomers and complex network structures. For future developments in the field it is essential that all aspects of the elastomer are taken into account, namely dielectric losses, lifetime and the very often ignored polymer network integrity and stability.Complete Manuscript

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Section: Investigated Silicone Materials For Dielectric Elastomersmentioning

confidence: 97%

Section: Investigated Silicone Materials For Dielectric Elastomersmentioning

confidence: 99%

The Current State of Silicone-Based Dielectric Elastomer Transducers

Madsen

Daugaard

Hvilsted

et al. 2016

Macromol. Rapid Commun.

369

392

View full text Add to dashboard Cite

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“…To avoid phase segregation, only relatively low fractions of the polar components were used. Consequently, the permittivity of the resulting materials was always below 6 . For the case where a nitrile‐functionalized polysiloxane was used as polar component, one of the best materials has a Y ≈ 300 kPa, ε′ ≈ 5, and shows an actuation strain of about 1% and 7% at electric fields of 10 and 20 V µm −1 , respectively …”

Section: Synthesis and Actuation Of High Dielectric Permittivity Elasmentioning

confidence: 99%

Polar Elastomers as Novel Materials for Electromechanical Actuator Applications

2017

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Dielectric elastomer actuators are stretchable capacitors capable of a musclelike actuation when charged. They will one day be used to replace malfunctioning muscles supposing the driving voltage can be reduced below 24 V. This focus here is on polar dielectric elastomers and their behavior under an electric field. Emphasis is placed on all the features that are correlated with the molecular structure, its synthetic realization, and its impact on properties. Regarding the polymer class, the focus, to some degree, is on polysiloxanes because of their attractively low glass transition temperatures. This enables introduction of highly polar groups to the backbone while maintaining soft elastic properties. The goal is to provide a few guidelines for future research in this emerging field that may be useful for those considering entering this fascinating endeavor. Because of the large number of materials available, a few restrictions in the selection have to be applied.

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“…Three different approaches were followed to prepare silicone elastomers containing polar CN groups. The first one uses a functional cross-linker that carries a CN group, 28 the second one uses a silicone modified with polar CN groups as high permittivity filler and cross-linker, 29,30 while the third approach uses a one step process in which the polar CN groups and the cross-linking occur simultaneously. 21 In the first approch, a hydroxyl end-functionalized polydimethylsiloxane (M W = 139 kDa) was cross-linked via a condensation reaction with varying amounts of 3-cyanopropyltriethoxysilane (Scheme 3).…”

Section: Silicone Based Elastomers Modified With Polar Cn Groupsmentioning

confidence: 99%

“…These fillers were either crosslinked into interpenetrating networks with a polydimethylsiloxane matrix or processed into nanoparticles that were blended into a polydimethylsiloxane matrix with good mechanical properties. 30 This approach led to novel materials with excellent mechanical properties and high breakdown fields (E b = 56 V/μm). The level to which the permittivity increased (ε' = 4.5) leaves space for further improvement.…”

Section: Silicone Based Elastomers Modified With Polar Cn Groupsmentioning

confidence: 99%

Silicones with enhanced permittivity for dielectric elastomer actuators

et al. 2016

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The research efforts for silicone based elastomers with high dielectric permittivity (ε') intensified significantly in the last years since such materials would allow the construction of dielectric elastomer actuators (DEA) with low operation voltages. Polar groups can be introduced to elastomers to adjust their permittivity. The results obtained regarding the functionalization of silicones with polar nitrile (CN) and trifluoropropyl (CF 3) groups are presented. Those with CN groups were synthesized via anionic polymerization of nitrile containing cyclosiloxanes or via a post-polymerization modification of functional polysiloxanes. Polysiloxanes containing CF 3 groups were prepared by anionic copolymerization of 1,3,5-tris(3,3,3-trifluoropropyl)-1,3,5-trimethylcyclosiloxane with octamethylcyclotetrasiloxane. Importantly, we have found that all polysiloxanes have glass transition temperatures (T g) well below room temperature (<-50 °C). This ensures that the materials turn into true elastomers after cross-linking. In addition to this, a linear increase in ε' with increasing content of polar groups was observed with maximum values of ε' = 18 and ε' = 8.8 for polysiloxanes modified at every repeating unit with either CN or CF 3 groups, respectively.

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Polar–nonpolar interconnected elastic networks with increased permittivity and high breakdown fields for dielectric elastomer transducers

Abstract: Polysiloxanes with polar cyano groups were cross-linked with PDMS by a hydrolysis–condensation process. Materials suitable for transducer applications with improved permittivity, good mechanical properties, and high breakdown fields were obtained.

Cited by 34 publications

References 38 publications

The Current State of Silicone-Based Dielectric Elastomer Transducers

The Current State of Silicone-Based Dielectric Elastomer Transducers

Polar Elastomers as Novel Materials for Electromechanical Actuator Applications

Silicones with enhanced permittivity for dielectric elastomer actuators

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