Orthopaedic Applications of Ferromagnetic Shape

Ferromagnetic shape memory alloys (FSMAs) are a new class of magnetic field-actuated active materials with no current commercial applications. By applying a magnetic field of around 0.4 T, they can exert a stress of approximately 1.5 MPa, exhibiting a strain of up to 6%. This thesis evaluates their technical and commercial feasibility in orthopaedic applications. Remote actuation is a key advantage FSMAs have over current implant materials. Also, the human body temperature is constant, providing a stable environment for FSMAs to operate. A number of potential orthopaedic applications are proposed and evaluated. Out of these, the most prominent application is the spinal traction device. It is a temporary implantable device, intended to perform internal spinal traction. A design has been proposed, with suggestions of suitable materials for its various components and appropriate device dimensions. Preliminary market and cost analyses have been conducted. This orthopaedic technology is currently in its infant stage. To commercialize this device, more trials are needed. Thesis Supervisor: Samuel M. Allen Title: POSCO Professor of Physical Metallurgy