TY  - JOUR
A1  - Risse, Sebastian
A1  - Kussmaul, Björn
A1  - Krüger, Hartmut
A1  - Kofod, Guggi
T1  - A versatile method for enhancement of electromechanical sensitivity of silicone elastomers
JF  - RSC Advances
N2  - Dielectric elastomer actuators (DEAs) draw their function from their dielectric and mechanical properties. The paper describes the fabrication and various properties of molecularly grafted silicone elastomer films. This was achieved by addition of high-dipole molecular co-substituents to off-the-shelf silicone elastomer kits, Elastosil RT 625 and Sylgard 184 by Wacker and Dow Corning, respectively. Strong push-pull dipoles were chemically grafted to both polymer networks during a one step film formation process. All manufactured films were characterized using (13) C-NMR and FT-IR spectroscopy, confirming a successful attachment of the dipoles to the silicone network. Differential scanning calorimetry (DSC) results showed that grafted dipoles were distributed homogeneously throughout the material avoiding the formation of nano-scale aggregates. The permittivity increased with the amount of dipole at all frequencies, while the Young's modulus and electrical breakdown strength were reduced. Actuation strain measurements in the pure shear configuration independently confirmed the increase in electromechanical sensitivity. The ability to enhance electromechanical properties of off-the-shelf materials could strongly expand the range of actuator properties available to researchers and end-users.
Y1  - 2012
U6  - https://doi.org/10.1039/c2ra21541a
SN  - 2046-2069
VL  - 2
IS  - 24
SP  - 9029
EP  - 9035
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Kussmaul, Björn
A1  - Risse, Sebastian
A1  - Wegener, Michael
A1  - Kofod, Guggi
A1  - Krüger, Hartmut
T1  - Matrix stiffness dependent electro-mechanical response of dipole grafted silicones
JF  - Smart materials and structures
N2  - The properties of dielectric elastomer actuators can be optimized by modifying the dielectric or mechanical properties of the dielectric elastomer. This paper presents the simultaneous control of both dielectric and mechanical properties, in a silicone elastomer network comprising cross-linker, chains and grafted molecular dipoles. Chains with two different molecular weights were each combined with varying amounts of grafted dipole. Chemical and physical characterization showed that networks with stoichiometric control of cross-linking density and permittivity were obtained, and that longer chain lengths resulted in higher electrical field response due to the reduction in cross-linking density and correspondingly in mechanical stiffness. Both actuation sensitivities were enhanced by 6.3 and 4.6 times for the short and long chain matrix material, respectively.
Y1  - 2012
U6  - https://doi.org/10.1088/0964-1726/21/6/064005
SN  - 0964-1726
VL  - 21
IS  - 6
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  -