Prosthetic finger movement simplified

I have seen many research paper dedicated to enabling finger movement when the user needs to catch something. For something to move with 1 degree of motion only needs 1 axial of motion. Hence, I propose the idea of having a balloon attached to both ends of the finger joint and a pump to push fluid into or out of the balloon. And the expansion and contraction of the balloon would enable finger motion. For a normal human being, to grab something is to push the object against the palm and the fingers. So, if the pump were to be placed at the palm, this same action would initiate the appropriate curvature of the prostatic finger to be able to grab and hold onto anything (e.g. glass of water)

There are many advantages to this design:

1. The fluid could be water or air. So, the user does not need to worry about replacement of fluid if something were to go wrong
2. The balloon could be made to rubber or the various forms of polymers, which help the user plug hole if any occur due to frequent usage or find a cheap replacement
3. Due to cleverly positioning the pump at the palm, the user with the prostatic finger would have the correct motion of fingers to hold an object

Legend:



Blue – the 2 parts of the finger to move about an axis

Red – pump

Arrow show the direction of fluid flow

This help us visualize the concept