At the invitation of David Clarke on behalf of the UCSB/Los Alamos Institute of Multiscale Materials and Structures, I gave the following three lectures:
The abstracts follow, and the slides are attached at the end of this post.
I'm attaching slides of a talk that I gave yesterday at the Schlumberger-Doll Research Center. In preparing the talk, I made liberal use of slides prepared by Wei Hong for his own presentations. The talk is mainly based on the following papers:
This letter describes a method to analyze electromechanical stability of dielectric elastomer actuators. We write the free energy of an actuator using stretches and nominal electric displacement as generalized coordinates, and pre-stresses and voltage as control parameters. When the Hessian of the free-energy function ceases to be positive-definite, the actuator thins down drastically, often resulting in electrical breakdown. Our calculation shows that stability of the actuator is markedly enhanced by pre-stresses.
Active polymers are being developed to mimic a salient feature of life: movement in response to stimuli. Large deformation can lead to intriguing phenomena; for example, recent experiments have shown that a voltage can deform a layer of a dielectric elastomer into two coexistent states, one being flat and the other wrinkled. This observation, as well as the needs to analyze large deformation under diverse stimuli, has led us to reexamine the theory of electromechanics.
