Electrorheological elastomers useful as variable stiffness articles
AssigneeFord Motor Company
InventorsMark E. Nichols, John M. Ginder, Larry D. Elie, Robert A. Pett
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Abstract
This invention is directed to an ER elastomer composition comprising natural rubber and polarizable particles dispersed therein, which elastomer can undergo changes in Youngs modulus when subjected to an electric field and having a Youngs modulus of at least about 2 Mpa when not subject to an electric field, wherein the ratio of the electrical conductivity of the particles to the electrical conductivity of the natural rubber is between about 10.sup.4 and 10.sup.10. The invention also include variable stiffness mounts, such as engine mounts, made from the composition.
Claims8
An electrorheological elastomer composition comprising natural rubber and polarizable particles dispersed therein in a weight ratio of 1:0.5-3.5 of natural rubber:particles, said elastomer (a) having a Youngs modulus of at least about 2 MPa and (b) undergoing changes in said modulus when subjected to a changing electric field, wherein the ratio of the electrical conductivity of said particles to the electrical conductivity of said natural rubber is between about 10.sup.4 and 10.sup.10, said particles consisting of inorganic semiconductor materials selected from the group consisting of aluminosilicate, silicon, germanium, gallium arsenide, group II-IV compound semiconductor materials and metal oxide compounds.
An article comprising an eletrorheological elastomer composition comprising natural rubber and polarizable particle dispersed therein in a weight ratio of 1:0.5-3.5 of natural rubber:particles, said elastomer (a) having a Youngs modulus of at least about 2 MPa and (b) undergoing changes in said modulus when subjected to a changing electric field, wherein the ratio of the eletrical conductivity of said particles to the electrical conductivity of said natural rubber is between about 10.sup.4 and 10.sup.10, said particles consisting of inorganic semiconductor materials selected from the group consisting of aluminosilicate, silicon, germanium, gallium arsenide, group II-IV compound semiconductor materials and metal oxide compounds.
An engine mount comprising an electrorheological elastomer composition comprising natural rubber and silicon particles dispersed therein, said elastomer (a) having a Youngs modulus of at least about 2 Mpa and (b) undergoing changes in said modulus when subjected to a changing electric field, wherein the ratio of the electrical conductivity of said particles to the electrical conductivity of said natural rubber is between about 10.sup.4 and 10.sup.10, said silicon being present in said elastomer in a weight ratio between about 0.5-3.5:1 based on the weight of said natural rubber.
Dependencies are inferred from the claim text.