Design of semi-active variable impedance materials using field-responsive fluids

In this thesis, I explored the design of a thin variable impedance material using electrorheological (ER) fluid that is intended to be worn by humans. To determine the critical design parameters of this material, the shear response of a sandwich of electrodes separated by ER fluid and several different spacer materials was investigated. After a preliminary test to verify that the shear response is controllable by an applied voltage, a single-axis tensile testing machine was designed and constructed to carry out more accurate testing. Two different ER fluids, homogeneous and heterogeneous were investigated. A model of the material for each fluid along with a general model were developed and the parameters of the models were determined through experiments. The model shows a good fit to the experimental data for the heterogeneous fluid based materials, with prediction errors on the order of 30% for two of the spacer materials. The homogeneous fluid based materials show a strong deviation from the model at OV, but fit well when voltage was applied. Polypropylene as a spacer dramatically reduced or eliminated the ER effect. Some critical design parameters identified include: variation in electrode spacing, spacer material selection, and breakdown levels.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2004

Author dc:creator

• Eastman, Douglas Elmer

Advisor dc:contributor.advisor

• Neville Hogan.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/34151

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/34151