Exploiting micro-structural design to enhance the performance of soft materials

David Wang Auditorium, 3rd floor Dalia Maydan Bldg.
Dr. Noy Cohen

Dr. Noy Cohen

Materials Department, University of California, Santa Barbara noyco5@gmail.com

Following a short overview of my recent work on the modelling of the electromechanical response of liquid metal embedded elastomers and the non-linear behavior of cellular materials, this seminar will focus on the coupled electro-mechanical response of dielectric elastomers (DEs). DEs are materials capable of undergoing large deformations in response to electric excitation. These dielectrics can be employed in a wide variety of applications, such as sensors, actuators, and energy harvesting devices. Currently, the functionality of these materials is limited due to the high electric fields required to obtain meaningful deformations. To overcome this obstacle, a better understanding of the influence of the micro-structural constituents on the overall behavior is required. To this end, I present a rigorous multi-scale entropy-based analysis that begins with a single dipolar monomer and accounts for the physical structure of a polymer chain through statistical considerations. By employing the laws of thermodynamics and variational formulations, the macroscopic response of a polymer network subjected to a coupled electro-mechanical loading is determined. The merit of the proposed model is demonstrated through a comparison with several experimental findings.