Leaf Spring with High Resolution Stiffness Control

A variable stiffness leaf spring mechanism and method of locking parallel leaf springs allow for a wide range of stiffness settings in a low-mass package. By varying the number of parallel leaf springs as well as the thickness and stiffness of each layer the system stiffness and range of stiffness settings can be optimally tuned to each application. Additionally, by locking leaf springs without inducing large normal forces from a clamping mechanism, the frictional wear on the system is greatly diminished. In addition to increasing the life cycles of the system, this will decrease auditory noise emitted during operation. The system and method can be applied to lower extremity prostheses to allow for more biological emulation than passive prostheses in a lower mass package than powered prostheses.