The SFSA Ankle: A Novel Smart Fluidic Servo Actuator for Low-Cost, Low-Power, High-Efficiency Transtibial Prosthetics

Modern prosthetic limb technology continues to evolve rapidly, with more focus on control and human-prosthetic interaction. However, overall accessibility to powered prosthetics remains low due to specific issues with power efficiency and cost. This paper presents the design and evaluation process of a novel electrofluidic actuator implemented in an ankle prosthetic, which is able to address the aforementioned problems through mechanical innovation. The actuator was developed through a three-stage process: proof-of-concept, theoretical evaluation, and empirical evaluation. The end results prove that the implementation of this actuator in an ankle prosthetic results in an up to 94% reduction in cost while maintaining a max current draw equivalent to standard powered prosthetics’ continuous current draw. These results prove the actuator’s efficacy as an alternative to conventional joint actuation in powered prosthetics.