pls help me to make a robotic arm which moves though a specific path.
Mechanical hand http://slsa.3dn.ru/load/1
YOu would need: a) a suitable robot arm B) a controller that can remember the training path c) quite a lot of electronics and controller software to make it work.
Tried websearching yet? There are a lot of designs; which one is appropriate depends on what you actually want the arm to do.