Now into robotics
Robotics is the field of biomechanical science where the knee is made of various materials and replaces the lost knee.
(source: singularity, where man and machine merge, by ray kurzweil). Or it can be separattheron body, serving some human need (source: the age of artificial machines, by ray kurzweil--since ur wondering, our fathers were brothers). Regarding fields to go in: this one is hot.