Magnetorheological fluid compositions and prosthetic knees utilizing same

A magnetorheological fluid consisting of polarizable particles and a fluid component,

• wherein the fluid component consists essentially of a carrier fluid and an additive;
• wherein the carrier fluid consists essentially of one of the group consisting of silicone, hydrocarbon, esters, ethers, fluorinated esters, fluorinated ethers, mineral oil, and unsaturated hydrocarbons;
• and
• wherein the additive consists essentially of a functionalized perfluorinated polyether fluid.

A magnetorheological fluid comprising polarizable particles and a fluid component

• wherein the fluid component consists essentially of a carrier fluid and an additive;
• wherein the carrier fluid consists essentially of one of the group consisting of silicone, hydrocarbon, esters, ethers, fluorinated esters, fluorinated ethers, mineral oil, and unsaturated hydrocarbons;
• and
• wherein the additive consists essentially of a functionalized perfluorinated polyether fluid
• wherein the functionalized perfluorinated polyether fluid additive comprises a poly(hexafluoropropylene epoxide) with a carboxylic acid located on the terminal fluoromethylene group.

A magnetorheological fluid comprising:

• about 32% (v/v) polarizable iron particles;
• and
• about 68% (v/v) fluid component;
• wherein said fluid component consists essentially of about 5% (v/v) additive and about 95% (v/v) perfluorinated polyother carrier fluid;
• wherein said additive consists essentially of poly(hexafluoropropylene epoxide) with a carboxylic acid located on the terminal fluoromethylene group.