Knee Goo
Magneto-Rheological fluids, those goopy concoctions of magnetic particles and oil have long been used only for damper systems in buildings and cars are now finding a use a little closer to you and me. Researchers at Northeastern University in Boston are bringing "smart fluids" to rehabilitative devices used after knee surgery. Using electro-rheological fluids, Professor Constantinos Mavroidis and Brian Weinberg, a research engineer and a mechanical engineering graduate student, plan to build a brace system that applies varying resistances to the recovering knee. This resistance, like those encountered in physical therapy, helps to encourage joint and tendon healing after the surgery. ER fluids respond to applied voltage, rather than an applied magnetic field, like MR fluids do, which makes then slightly easier to integrate into a mechanical design.
