The functionality of Artificial hands is being expanded rapidly by some new developments that are changing things for people who use artificial hands. In 2005 a University of Southampton research team developed a prototype prosthesis that uses six sets of motors and gears to that each of the five fingers can move independently. Plus, the new hand has an opposing thumb that can rotate as well as "pinch". The next stage will be to integrate the latest Load cell technology to create a 'clever' hand which can sense how strongly it is gripping an object, or whether an object is slipping.
Another super prosthesis is being built by Advanced Arm Dynamics. It is faster than other myoelectric artificial hands, and has autograsp which allows the wearer to simply hold an object without wasting energy on monitoring whether the item is slipping or not.
Industrial robots have an amazing number of specialized artificial hands that can be used in a wide variety of jobs. A robot's artificial hand can pick heavy things up, or manipulate the most delicate of microchips. They can drill holes, operate spray painters, and tighten bolts. Even with all their capability, robotic artificial hands are simple when compared to an artificial hand for a human. Robots do one job over and over. On the other hand, Humans use their hands to do many different jobs. Robotic hands can be arbitrarily heavy since the robots don't get tired. Heavy prosthetics can be extremely uncomfortable and cause injury to the area where it joins with the arm. The human hand has 27 bones and can make a number of complex movements and actions. Robots working in industry need only the relatively limited motions dictated by their specific job so they can only clutch something in a single type of grip. Robotic hands, once they have grasped an object, don't let go until they are told to do so. A humanusing a real hand to grasp something simply invokes the 'keep holding until I tell you to do something else' behavior in their subconscious, so that a human using his real hand can walk and hold a cup of coffee at the same time. By contrast an advanced artificial hand requires much more conscious attention from the user to make sure the object isn't dropped.
One of the most difficult problems in designing a functioning artificial hand is making it responsive to muscular contractions of the wearer. A robotic hand, even a very complex hand with multiple fingers, is trivial to control by comparison.
