1/5/16

You are invited to attend a lecture

By

Electroactive Polymer Microactuators

Leeya Engel

Ph.D. student of

Professor Yosi Shacham-Diamand of Electrical Engineering, Physical Electronics Department and Professor Slava Krylov, of Mechanical Engineering, Tel Aviv University

The biomedical applications of electroactive polymer (EAP) actuators, also known as "artificial muscles", have the potential to vastly improve human life in tools for less invasive surgery, active prosthetics, and lab-on-a-chip devices. In this talk, I will present the emerging field of EAP micro-actuator systems, highlighting the actuation mechanisms of ionic and field-activated polymeric materials, while noting the importance of device scale. The main challenges inherent in developing these polymer microsystems lie in the integration of unconventional materials with silicon-based microsystems and the creation polymer-electrode interfacing that allows for chemically and mechanically stable operation. The goal of my work was to design and fabricate polymer microelectromechanical systems (MEMS) using novel EAP materials, which required actuator architectures and developing new microfabrication methodologies.

The main focus of the research was to explore the suitability of a promising relaxor ferroelectric polymer P(VDF-TrFE-CFE) for microsystems. This required developing custom micro/nanofabrication methodologies for patterning the smart material, such as thermoplastic nanoimprint lithography and developing an understanding of how processing conditions effect the material's electromechanical response. We demonstrated use of the material in two actuator configurations (1) A transparent buckling membrane actuator and (2) a self-sensing electroactive polymer bimorph actuator, which served as a platform for studying the frequency dependence of this EAP. In addition, we characterized the electromechanical response of a novel Pluronic-based biocompatible hydrogel developed for cardiovascular occlusion, shedding light on the role of current in the diffusion mechanisms behind electrically induced deformation of polymer hydrogels in salt solution.

Investigating the downscaled electromechanical and structural properties of smart polymers in actuator test structures contributes to the ”toolbox” of EAP actuator technologies by demonstrating feasibility and providing a scientific basis for understanding EAPs at small scales. These materials have the ability to exhibit property changes much beyond what is achievable with inorganic materials and, combined with their light weight, low-cost processing, flexibility and biocompatibility, present an attractive alternative material for device design. Recent advances in polymer microfabrication (i.e. imprint lithography, laser micromachining, and 3D printing), together with breakthroughs in materials science, and understanding of EAP behavior at these small scales will serve to overcome the technological barriers to full integration with microsystems and usher in a new paradigm of medical microsystems.

Sunday, May 1, 2016, at 11:10

Room 011, Kitot Building