Although of simple complexity and using low currents, this tDCS machine is still to be considered a piece of equipment that could be dangerous both in the assembly and in the operation phases, so please inform yourself as best as you can before either of these steps!
The Yale open hand project, has a similar purpose of the open hand project, that is, to make prosthetic hands more widely available through the lowering of costs. They have a different design from the open hand project.