Soft elastomeric material with improved dielectric permittivity
Shakun, Alexandra (2014)
Shakun, Alexandra
2014
Master's Degree Programme in Materials Science
Teknisten tieteiden tiedekunta - Faculty of Engineering Sciences
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Hyväksymispäivämäärä
2014-04-09
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tty-201405131161
https://urn.fi/URN:NBN:fi:tty-201405131161
Tiivistelmä
Dielectric elastomeric actuators (DEAs) tend to have good perspectives in artificial muscle applications. This class of materials has properties similar to the natural muscles. However, DEAs generally need very high actuation voltage that limits the possible applications and decreases the lifetime of an actuator. Although much research has been conducted to overcome the mentioned problems, efficient ways of lowering the working voltage are still in demand. Utilization of dielectric rubber composites is one of the popular approaches showing positive results. Namely, higher overall relative permittivity of the material allows reducing the actuation voltage if the mechanical properties are maintained at the initial level.
The aim of the current work is to modify acrylic and epichlorohydrin rubbers by addition of dielectric and ferroelectric fillers, as well as two types of dielectric transformer oils, in order to obtain the a material with enhanced dielectric permittivity and low modulus. Moreover, attention is paid to the mechanical properties, especially elastic Young’s modus and stress at 100 % elongation of the initial elastomers and obtained composites. The effect of crosslink densities of the vulcanizates are is also taken into consideration. While the actuation tests stay are outside the scope of this thesis, actuation behaviour of the materials can be estimated theoretically based on mechanical and dielectric properties. As a result, some improvement was gained in material performance; number of important conclusions about fabrication, sample preparation, dielectric measurements and directions of further research was drawn. Finally, theoretical and experimental knowledge obtained during the preparation of the thesis can be valuable for the further development of the research project.
The aim of the current work is to modify acrylic and epichlorohydrin rubbers by addition of dielectric and ferroelectric fillers, as well as two types of dielectric transformer oils, in order to obtain the a material with enhanced dielectric permittivity and low modulus. Moreover, attention is paid to the mechanical properties, especially elastic Young’s modus and stress at 100 % elongation of the initial elastomers and obtained composites. The effect of crosslink densities of the vulcanizates are is also taken into consideration. While the actuation tests stay are outside the scope of this thesis, actuation behaviour of the materials can be estimated theoretically based on mechanical and dielectric properties. As a result, some improvement was gained in material performance; number of important conclusions about fabrication, sample preparation, dielectric measurements and directions of further research was drawn. Finally, theoretical and experimental knowledge obtained during the preparation of the thesis can be valuable for the further development of the research project.