For centuries, manufacturers of limb prostheses have tried to maximally - externally and functionally - bring them closer to the missing "original". TouchBionics just posted a YouTube video detailing the steps to create hyper-realistic skin for limb prostheses, complete with nails, hair and texture.
It all starts with fixing the external physical characteristics of the limb (in this case, the hand) and creating its digital model for subsequent adjustment to select options for skin, hair, freckles, veins and nail shape.
Then the shape of the hand is cast: first, the hand is covered with a special compound, which, after drying, completely reproduces its configuration in the form of a kind of glove. Then another substance is poured into it, which, in turn, after cooling, repeats the cast of the hand, and the “glove”, which has become unnecessary, is removed.
The next stage is the application of a metal film to the product, after which the future prosthesis is filled with silicone. It is he who reproduces the final configuration of the limb in the form of a transparent flexible glove.
In conclusion - tuning, when the color of the skin, the shape of the nails, veins, hairs and even a tattoo are selected. After "vigorous testing", the prosthesis is equipped with electronics and mechanics.