Shape memory alloys (SMA) can be used for powerful, lightweight and highly dynamic drives in prosthetics and orthotics. This needs to be investigated and implemented. Specifically, FGL wires are to be energised and thus heated to reach the actuation temperature. The change in resistance that occurs can be used to record the deflection. With the help of suitable kinematics, swivel and linear actuators can be constructed whose force density can become remarkably high. To improve the dynamics, we are also working on adaptive cooling systems with which the FGL actuator can be quickly brought back to its initial temperature.
Test stand for evaluation of an SMA actuator for knee orthoses
Photo: Peter Emmerich