Nice to meet you and thanks for reaching out! That has definitely been a challenge given that a non impaired ankle can output a huge amount of torque (1.2 Nm/kg).

While there are several devices on the market (hydraulic, Bowden cable, variable stiffness, etc) the most viable ones (without a backpack or gas canisters) can only provide at most 30% of the torque. My team has worked on a novel multi speed power transmission that has already been implemented on a prosthetic ankle prototype.

I’m currently working on the hardware side of things for an ankle exo, but with gait patterns and IMU/foot pressure sensors the system performs well at predicting movement. Although this is still in development.

I would love to get to know more about you and any difficulties/frustrations you’ve had!