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   COLLOQUIUM OF THE LABORATORY FOR COMPUTER DESIGN OF MATERIALS
                   School of Computational Sciences
                           (CSI 898-Sec 001)
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                Conducting Polymer Micro-Actuators

                          Elisabeth Smela

   Department of Mechanical Engineering, University of Maryland
                          College Park, MD


Conjugated polymers are organic semiconductors and smart materials,
 and thus have a wide range of interesting applications, including 
actuators (or "artificial muscles").  These materials can be 
electrochemically oxidized and reduced by applying a small voltage, 
which changes their conductivity, color, volume, and other properties.  
Volume change is based on ion and water transport in and out of the 
polymer in response to the change in charge on the polymer backbone.  
We have developed micro-actuators based on bilayers of gold and 
polypyrrole and have demonstrated devices such as self-folding boxes 
and a micro-robot arm.  Current work includes basic studies of the 
volume change mechanisms:  physics-based models must be developed if 
we are to have a predictive capability that allows us to design improved 
systems.  For this, carefully designed experiments must be performed that 
are targeted to provide data needed by the models.  The models must 
ultimately take into account what is happening at the molecular level.  
This is challenging, but is in the long run is faster than experimentally 
searching the entire space of experimental variables, which is too large 
for that to be practical.  
		
                Monday , October 20, 2003
                         4:30 pm
                Room 206, Science & Tech. I

Refreshments will be served at 4:15 PM.
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Find the schedule at http://www.scs.gmu.edu/lcdm/seminar/schedule.html