Novel silicone elastomer formulations for DEAPs

Abstract

We demonstrate that the force output and work density of polydimethylsiloxane (PDMS) based dielectric elastomer transducers can be significantly enhanced by the addition of high permittivity titanium dioxide nanoparticles which was also shown by Stoyanov et al [1] for pre-stretched elastomers and by Carpi et al for RTV silicones [2]. Furthermore the elastomer matrix is optimized to give very high breakdown strengths. We obtain an increase in the dielectric permittivity of a factor of approximately 2 with a loading of 12% TiO 2 particles compared to the pure modified silicone elastomer with breakdown strengths remaining more or less unaffected by the loading of TiO 2 particles. Breakdown strengths were measured in the range from approximately 80-150 V/μm with averages of the order of 120-130 V/μm for the modified silicone elastomer with loadings ranging from 0 to 12%.

Silicone elastomers with high dielectric permittivity and high dielectric breakdown strength based on tunable functionalized copolymers

“…A reduction in elastic modulus is often the reason for reduced electrical breakdown strength due to electromechanical instability 32 . The enhancement in the properties of the dipolar elastomers can be compared with the PDMS reference material by calculating the figure of merit, F om , relative to the figure of merit for the reference film 20,33 . The figure of merit is a universal expression defined by Sommer-Larsen and Larsen 33 , which, through a single parameter, can be used to evaluate the performance of a DE (at a constant potential).…”

“…An alternative method is to chemically graft organic dipolar molecules to the silicone elastomer network. This approach potentially leads to a more controlled network structure, as it does not rely on the efficient and perfect mixing of particles or blends and should furthermore provide a more stable elastomer system upon continued actuation of the material 20 . A number of schemes has been developed with this approach in mind: Kussmaul et al 21 and Risse et al 22 added the synthesized dipolar molecule N-allyl-N-methyl-p-nitroaniline, together with compensating amounts of a hydride-functional cross-linker, to a PDMS matrix and a commercial silicone elastomer system, respectively, in one-step processes.…”

The electrical breakdown of thin dielectric elastomers: thermal effects

“…All samples were prepared based on the procedures described by Skov et al (2013) 10 as specified below:…”

Novel encapsulation technique for incorporation of high permittivity fillers into silicone elastomers

“…One of the most frequently reported methods is based on mixing elastomers with high permittivity fillers like carbon nanotubes, carbon black, titanium dioxide etc. [2,3]. Composites containing different amounts of fillers can potentially improve not only the actuation performance but also mechanical properties of final material.…”

“…= 0 = 0 (1 + ) [2] = 0 [3] Different approaches have been performed in order to increase relative permittivity of dielectric elastomers. One of the most frequently reported methods is based on mixing elastomers with high permittivity fillers like carbon nanotubes, carbon black, titanium dioxide etc.…”