[amelius]

You could add encoder patterns to the tendons, like stripes. And then use something like a mouse-sensor to track them. This is still much lighter than servos.

Another idea is to use an external camera or two and to track the fingers with a deep learning model. But this can become messy if other objects are in view. And it might also introduce more control delay in the feedback loop than a simple sensor.

[stefanka]

If space permits you should add absolute encoders in the joints. In a finger that’s likely a challenge. In an arm, that’s easy