A 6 degrees of freedom robotic prosthetic arm built during a masters level course at CMU.
My team focused on the 3 degrees of freedom upper arm and shoulder which is connected to the elbow and the plastic "backpack" that the user wears.
The upper arm and shoulder is made out of aluminium and carbon fibre. It uses bowden cables for flexion/ extension and abduction/ adduction.
It also uses an AC motor for medial rotation/ lateral rotation.
The arm is controlled by motors on the back (not seen in the picture) and could ostensibly grab an object the size of a soda can.
Music from https://www.youtube.com/watch?v=e53UZG6arjE