I am into flexible filament printing at the moment and this was my idea for 3D printing combination of materials, to give interesting results. This could be printed with a dual extruder machine, with each material being printed with each extruder.

The idea wasn't to offer a direct prosthetic, just to sow the seed of thought into those developers out there who are more specialised in this field. Having said that the hinged figers could be a direct replacement on the Robohand project, using nylon fishing wire as the tendons instead.