US Patent 7369396 Composite electroactive material for electromechanical actuators

A composite electroactive material having a plurality of particle cores, each particle core surrounded by a polymer covering having one or more strands of an electroactive polymer. In one embodiment, the particle cores have a relatively small size, e.g., between about 10 and 50 nm, and include a material having a relatively large dielectric constant, e.g., greater than about 30. Each polymer strand includes an electroactive elastomer that is bonded to the surface of the corresponding particle core by a linker. Representative examples of the particle core material, elastomer, and linker are titanium dioxide, polybutadiene, and a phosphonate group, respectively.