2026-09-18T22:20:55Zhttps://dspace.mit.edu/server/oai/request

oai:dspace.mit.edu:1721.1/1187092023-01-06T15:37:27Zcom_1721.1_7582com_1721.1_7581col_1721.1_131023

Xuanhe Zhao. Kim, Yoonho(Scientist in mechanical engineering) Massachusetts Institute of Technology Massachusetts Institute of Technology. Department of Mechanical Engineering. Massachusetts Institute of Technology. Department of Mechanical Engineering 2018-10-22T18:45:53Z 2018-10-22T18:45:53Z 2018 2018 http://hdl.handle.net/1721.1/118709 1057019702 Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2018. Cataloged from PDF version of thesis. Includes bibliographical references (pages 61-63). Soft materials capable of transforming between three-dimensional (3D) shapes have applications in areas as diverse as flexible electronics, soft robotics, and biomedicine. This thesis introduces a method of printing ferromagnetic domains in soft materials that yield fast transformation between complex 3D shapes via magnetic actuation. This approach is based on direct ink writing of an elastomer composite containing hard ferromagnetic microparticles. By applying a magnetic field to the dispensing nozzle while printing, we make the particles reoriented along the applied field direction to impart patterned magnetic polarity to printed filaments. This method allows us to design ferromagnetic domains in 3D-printed soft materials encoded with complex programmed shapes. A mathematical model based on a continuum mechanics framework is developed to predict such complex transformation of printed structures under the applied magnetic fields. For this computational model, a constitutive law is developed to describe the behavior of soft materials incorporating hard ferromagnetic microparticles under applied magnetic fields. The capability to quantitatively predict the shape changes enables designing a set of previously inaccessible modes of transformation such as remotely controlled 3D auxetic behaviors in an extremely fast and fully reversible manner via magnetic actuation. The actuation speed and power density of the printed soft materials with programmed ferromagnetic domains are orders of magnitude greater than existing 3D-printed active materials. Diverse functions derived from the fast and complex shape changes such as reconfigurable soft electronics, interaction with quickly moving objects, rolling-based locomotion and delivery of drug pills, and a horizontal leap of a 3D auxetic structure. by Yoonho Kim. S.M. 63 pages eng Massachusetts Institute of Technology MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission. http://dspace.mit.edu/handle/1721.1/7582 Mechanical Engineering. Printing ferromagnetic domains in soft materials : mechanism, modeling, and applications Thesis application/pdf false Publication unknown unknown <Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="0f6e4b3f-ade7-4057-8a6f-390405f815ec"> <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>Printing ferromagnetic domains in soft materials : mechanism, modeling, and applications</Title> <PublishedIn> <Publication> </Publication> </PublishedIn> <PublicationDate>2018</PublicationDate> <Authors> <Author> <DisplayName>Kim, Yoonho(Scientist in mechanical engineering) Massachusetts Institute of Technology</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>Soft materials capable of transforming between three-dimensional (3D) shapes have applications in areas as diverse as flexible electronics, soft robotics, and biomedicine. This thesis introduces a method of printing ferromagnetic domains in soft materials that yield fast transformation between complex 3D shapes via magnetic actuation. This approach is based on direct ink writing of an elastomer composite containing hard ferromagnetic microparticles. By applying a magnetic field to the dispensing nozzle while printing, we make the particles reoriented along the applied field direction to impart patterned magnetic polarity to printed filaments. This method allows us to design ferromagnetic domains in 3D-printed soft materials encoded with complex programmed shapes. A mathematical model based on a continuum mechanics framework is developed to predict such complex transformation of printed structures under the applied magnetic fields. For this computational model, a constitutive law is developed to describe the behavior of soft materials incorporating hard ferromagnetic microparticles under applied magnetic fields. The capability to quantitatively predict the shape changes enables designing a set of previously inaccessible modes of transformation such as remotely controlled 3D auxetic behaviors in an extremely fast and fully reversible manner via magnetic actuation. The actuation speed and power density of the printed soft materials with programmed ferromagnetic domains are orders of magnitude greater than existing 3D-printed active materials. Diverse functions derived from the fast and complex shape changes such as reconfigurable soft electronics, interaction with quickly moving objects, rolling-based locomotion and delivery of drug pills, and a horizontal leap of a 3D auxetic structure.</Abstract> <Access xmlns="http://purl.org/coar/access_right" > </Access> </Publication>