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Ian W. Hunter. Fofonoff, Timothy Andrew, 1977- Massachusetts Institute of Technology. Dept. of Mechanical Engineering. Massachusetts Institute of Technology. Department of Mechanical Engineering 2009-08-26T16:32:40Z 2009-08-26T16:32:40Z 2008 2008 http://hdl.handle.net/1721.1/46482 399645344 Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008. Includes bibliographical references (leaves 128-135). The development of biomimetic devices will benefit from the incorporation of actuators with combinations of properties common to biological systems, for example low density, controllable mechanical flexibility, and compact size. Conducting polymers, such as polypyrrole, exhibit muscle-like properties and the potential to provide the above capabilities while delivering significant forces over useful displacements. Current conducting polymer linear actuators, however, are generally limited to displacements of less than 0.5 mm, forces of less than 1 N, and cycle frequencies of less than 0.1 Hz. These materials are rarely tested on a length scale of more than a few millimeters, and their incorporation into real applications has to date been limited. This work focuses on improving and scaling conducting polymer linear actuators for application in macroscale systems. A new fabrication method is described that delivers polypyrrole ribbons with uniform thicknesses of 10 to 30 [mu]m, widths of 20 [mu]m to 20 mm, and lengths exceeding 5 m. A second method is described where a conductive gold layer is incorporated into the ribbons and is shown to enhance performance and mitigate limiting effects common to longer conducting polymer actuators. Additionally, parallel actuation is explored as a method to achieve greater forces without compromising actuation speed. The integration of these actuators into stand alone systems that include joints and flexures has yielded novel techniques in amplifying motion while minimizing friction, improving electrical connection, and increasing actuator lifetime. The challenges of incorporating these actuators into an example biomimetic system are discussed and an approach is introduced. These methods and systems are shown to have increased conducting polymer linear actuator displacement output, force output, and actuation speed each by a full order of magnitude, thus bringing this technology closer to practical incorporation and use in biomimetic systems. by Timothy Andrew Fofonoff. Ph.D. 135 leaves eng Massachusetts Institute of Technology 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. http://dspace.mit.edu/handle/1721.1/7582 Mechanical Engineering. Fabrication and use of conducting polymer linear actuators Thesis application/pdf false Publication unknown unknown <Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="fba31ea6-2236-4da4-a1b5-132a73db711c"> <Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843</Type> <Language>eng</Language> <Title>Fabrication and use of conducting polymer linear actuators</Title> <PublishedIn> <Publication> </Publication> </PublishedIn> <PublicationDate>2008</PublicationDate> <Authors> <Author> <DisplayName>Fofonoff, Timothy Andrew, 1977-</DisplayName> <Affiliation> <OrgUnit> </OrgUnit> </Affiliation> </Author> </Authors> <Editors> </Editors> <Publishers> <Publisher> <DisplayName>Massachusetts Institute of Technology</DisplayName> <OrgUnit /> </Publisher> </Publishers> <License>http://dspace.mit.edu/handle/1721.1/7582</License> <Keyword>Mechanical Engineering.</Keyword> <Abstract>The development of biomimetic devices will benefit from the incorporation of actuators with combinations of properties common to biological systems, for example low density, controllable mechanical flexibility, and compact size. Conducting polymers, such as polypyrrole, exhibit muscle-like properties and the potential to provide the above capabilities while delivering significant forces over useful displacements. Current conducting polymer linear actuators, however, are generally limited to displacements of less than 0.5 mm, forces of less than 1 N, and cycle frequencies of less than 0.1 Hz. These materials are rarely tested on a length scale of more than a few millimeters, and their incorporation into real applications has to date been limited. This work focuses on improving and scaling conducting polymer linear actuators for application in macroscale systems. A new fabrication method is described that delivers polypyrrole ribbons with uniform thicknesses of 10 to 30 [mu]m, widths of 20 [mu]m to 20 mm, and lengths exceeding 5 m. A second method is described where a conductive gold layer is incorporated into the ribbons and is shown to enhance performance and mitigate limiting effects common to longer conducting polymer actuators. Additionally, parallel actuation is explored as a method to achieve greater forces without compromising actuation speed. The integration of these actuators into stand alone systems that include joints and flexures has yielded novel techniques in amplifying motion while minimizing friction, improving electrical connection, and increasing actuator lifetime. The challenges of incorporating these actuators into an example biomimetic system are discussed and an approach is introduced. These methods and systems are shown to have increased conducting polymer linear actuator displacement output, force output, and actuation speed each by a full order of magnitude, thus bringing this technology closer to practical incorporation and use in biomimetic systems.</Abstract> <Access xmlns="http://purl.org/coar/access_right" > </Access> </Publication>