New Artificial Muscles to Generate Human Movements in Robots

  One of the reasons you realize that a robot like this is indeed artificial and not a human being is because it's movements are jumpy and jerky. So what exactly is the difference between a mechanical movement and a "natural" one?  And is it possible to make a robot move more "naturally?"

   Jun Ueda, Assistant Professor at the Georgia Institute of Technology (photo), is set to find that out.
 
  In a human being, every time there is an electric signal from the brain - let's say - to wave an arm, different cells respond to that signal. The stochastic - or random - way the cells respond to a certain signal explains why every wave of the arm is slightly different from the last, which is something that doesn't occur with robots. A robot's wave will be exactly the same every time.
 
  So Prof. Ueda is developing a "stochastically-controlled, biologically-inspired actuator" to see if he can imitate the stochastic human process in robots. With current artificial muscles, if you send a signal at a regular interval, the movement will be jerky. Prof. Ueda thinks with his new cell-structured actuator combined with the right timing of electric pulses, he could generate a natural motion artificially.

(Photo: Actuator using 6 piezoelectric devices.) 
 
  The new actuator is made from an array of small piezoelectric devices (cells) that are linked together to build a muscle-like formation. Each device can only move a tiny bit depending on the electric voltage but linking many of them together and covering them with a mechanical frame enables it to make bigger strokes as a whole. The new actuator can respond more quickly than the existing artificial muscles which use air pumps or shape memory alloys. The cell structure is also useful in a way that you can change the length and size of the artificial muscle, as well as fix it more easily by replacing the tiny devices.

(Photo: Goal is to create a human muscle-like structure using a number of the small actuators, as seen in the model on the left. Sending electric signals to each actuator (cell) randomly may realize movements that are closer to humans.)
   
  Besides the intellectual merit of finding out the "missing link" that bridge the gap between biological movements and artificial ones, Prof. Ueda is eager to develop a robotic arm driven by a number of stochastic array actuators.