Conducting polymer actuators : temperature effects

Abstract

In order to utilize conducting polymer actuators as a viable engineering solution, it is necessary to produce usable levels of force with a reasonable bandwidth. Polypyrrole actuated at temperatures as high as 100 °C increases stress magnitudes by as much as 4x and stress rates by 5x. The effect is caused by a combination of decreased solution resistance and increased ion diffusion within the polymer. However, these temperatures cause accelerated degradation due to the time-temperature correlation common to viscoelastic polymers. Actuation at these temperatures can decrease cycle life by as much as 20x. Excessive heating without actuation can also result in poor actuator performance. Impedance spectroscopy coupled with electro-mechanical analysis highlighted previous results and also showed an improved frequency response from actuation at high temperatures.