The need for high driving electric fields currently limits the diffusion of dielectric elastomer actuation in some areas of
potential application, especially in the case of biomedical disciplines. A reduction of the driving fields may be achieved
with new elastomers offering intrinsically superior electromechanical properties. So far, most of attempts in this
direction have been focused on composites between elastomer matrixes and high-permittivity ceramic fillers, yielding to
limited results. In this work, the electromechanical response of a silicone rubber (poly-dimethyl-siloxane) was improved
by blending, rather than loading, the elastomer with a highly polarizable conjugated polymer (undoped poly-hexyl-thiophene).
Very low percentages (1-6 wt%) of poly-hexyl-thiophene yielded both an increase of the dielectric
permittivity and an unexpected reduction of the tensile elastic modulus. Both these factors contributed to a remarkable
increase of the electromechanical response, which reached a maximum at 1 wt% content of conjugated polymer. This
approach may lead to the development of new types of improved dielectric elastomers for actuation.
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