michinyon:
It's known that the major part of the use of our hand is just grasping.
Known by who ? You just claiming it, does not make it true.
As I said, I type thousands of characters a day, and I pick up maybe a dozen things.
I quite like your hand, it's good ! It is just the dodgy claims in your captions that I don't like.
My source is a TED Lecture i saw about the "Intelligence of hand", by Antonio Bicchi, who is a Professor of Robotics at University of Pisa. You can find it here:
but unfortunately I found it only in Italian. He explains that our human hand is incredibly complex, and has more than 20 degrees of freedom. Nevertheless, we can have a quite useful robot hand with only ONE degree of freedom, and in his lecture he explains the possible important implications of this discovery.
Above all, he says this can be useful to make simple but light and cheap prosthetic hand.
My youtube video is not a TED talk, and I'm not a professor of Robotics and I've not 20 minutes to explain my ideas. I just tried to summarize all the important facts in just one frame, and English is not even my mother language. If you find my effort a "dodgy claim", I don't know what to say 
michinyon:
you did claim that your hand uses only one motor/servo. To have a usable hand for picking anything up,
you would need some kind of arm which will require more than one motor or servo.
Sorry but I think you confuse the end effector with the rest of the robot (whatever it is). The end effector I realized is complete, and requires only one motor to do his job (grasp something). You can just google "end effector"...
Then, if you want to realize a whole humanoid robot, probably you will need other 40 motors, but this is another issue. 