Date of Award

5-2014

Level of Access

Campus-Only Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Mechanical Engineering

Advisor

Mohsen Shahinpoor

Second Committee Member

Vincent Caccese

Third Committee Member

Senthil Vel

Abstract

This dissertation is concerned with three major areas pertaining to the experimental and theoretical characterization, fabrication and application of Ionic- Polymer-Metal-Composites (IPMCs).

The first effort is focused on the characterization and modeling of IPMC for curvature monitoring of deployable/inflatable dynamic structures. We explore the dynamic response of an IPMC sensor strip with respect to the controlled curvature deformations subjected to different forms of input functions. Experimental results show that IPMC sensor maintains linearity, sensitivity and repeatability required for curvature sensing. Besides, in order to describe the dynamic phenomena such as rate dependency of IPMC sensor, a chemo-electro-mechanical model based on Poisson-Nernst-Planck (PNP) equation for the kinetic of ion diffusion is presented. By solving the governing PDE equations the frequency response of the IPMC sensor is derived. The presented multiphysics model describes the dynamic properties of IPMC sensor and the dependency of signal on rate of excitations.

The second area addressed in this dissertation involves the fabrication of a novel multi-functional ionic polymeric transducer based on poly (ethylene-co-methacrylic acid) or (E-MMA) ionic polymer in a nanocomposite form with a metal. The polymeric backbone of the ionic actuator is the commercially available ionic polymer called Surlyn® ionic polymer by DuPont. Surlyn® is a copolymer of ethylene and methacrylic acid groups which is partially neutralized with Na+ ions. The existence of cation-exchange sites as well as the porosity of the membrane allowed it to perform a redox-based electroless chemical plating to form highly conductive electrodes on both sides. E-MMA-IPMC exhibits actuation with high efficiency. Besides, high sensitivity and accuracy to the applied mechanical excitations is observed in the sensing mode.

The last area of this dissertation is concerned with the application of IPMCs in minimally invasive surgery procedures. Novel bio-compatible electro-active polymeric actuators can improve the design and functionality of the robotic forceps through introducing smaller and more flexible robotic end-effectors. Here, we introduce the application of IPMCs as flexible actuators with embedded tactile and force feedback sensors for minimally-invasive surgery. It is shown that with a customized fabrication of IPMC, the two degrees of freedom IPMC actuator maintains the required dexterity for two-dimensional manipulation of a robotic distal tip.

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