{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/29807"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/29807","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Investigation of defects on acoustic scattering in cloak by molding process","abstract":"For this paper, molding- and casting-based microfabrication of metal microstructures was developed in order to replicate the acoustic cloak. The metal was cast into a stretchable PDMS mold, which was cast from micromachined aluminum cloak. For the PDMS mold, the mold release agent, trichlorosilane ([tridecafluoro-1,1,2,2-tetrahydrooctyl] trichlorosilane), was enhanced to imprint the micro-sized features of aluminum cloak in a circular area with a diameter of 105mm. This micromold process with trichlorosilane was also demonstrated by casting silicone rubber into original acoustic cloak. The low-temperature metal alloy, CerroBend, was used to microcast the metamaterial networks at a melting point of 70°C. Some damaged replicas were prepared to investigate defects in the cloak, and the performance of the broken cloak was estimated by the acoustic measurement in the water at an operating frequency of 60 kHz. We demonstrated that the broken cloak could accomplish the cloaking function depending on the direction of defects. Moreover, this study of microcasting process for the mass production and investigation of the defects in the acoustic cloak may apply to the understanding of the broken symmetric effects of an acoustic metamaterial.","abstract_html":"For this paper, molding- and casting-based microfabrication of metal microstructures was developed in order to replicate the acoustic cloak. The metal was cast into a stretchable PDMS mold, which was cast from micromachined aluminum cloak. For the PDMS mold, the mold release agent, trichlorosilane ([tridecafluoro-1,1,2,2-tetrahydrooctyl] trichlorosilane), was enhanced to imprint the micro-sized features of aluminum cloak in a circular area with a diameter of 105mm. This micromold process with trichlorosilane was also demonstrated by casting silicone rubber into original acoustic cloak. The low-temperature metal alloy, CerroBend, was used to microcast the metamaterial networks at a melting point of 70°C. Some damaged replicas were prepared to investigate defects in the cloak, and the performance of the broken cloak was estimated by the acoustic measurement in the water at an operating frequency of 60 kHz. We demonstrated that the broken cloak could accomplish the cloaking function depending on the direction of defects. Moreover, this study of microcasting process for the mass production and investigation of the defects in the acoustic cloak may apply to the understanding of the broken symmetric effects of an acoustic metamaterial.","abstract_has_math":false,"creators":["Cho, Shinhu"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Mechanical Engineering","degree_department":null,"school":null,"contributors":["Fang, Nicholas X."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2012,"date_issued":"2012-02-06T20:18:20Z","date_published":"2012-02-06T20:18:20Z","updated_at":"2026-07-22T22:25:29Z","subjects":["Acoustic Metamaterial","Micro-molding","Micro-casting","Scattering effect"],"languages":["en"],"rights":["Copyright 2011 Shinhu Cho"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/29807","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Fang, Nicholas X."]},{"key":"dc:creator","label":"Author","values":["Cho, Shinhu"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2012-02-06T20:18:20Z","2011-12"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation / Thesis","text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mechanical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Acoustic Metamaterial","Micro-molding","Micro-casting","Scattering effect"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2011 Shinhu Cho"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/29807"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["For this paper, molding- and casting-based microfabrication of metal microstructures was developed in order to replicate the acoustic cloak. The metal was cast into a stretchable PDMS mold, which was cast from micromachined aluminum cloak. For the PDMS mold, the mold release agent, trichlorosilane ([tridecafluoro-1,1,2,2-tetrahydrooctyl] trichlorosilane), was enhanced to imprint the micro-sized features of aluminum cloak in a circular area with a diameter of 105mm. This micromold process with trichlorosilane was also demonstrated by casting silicone rubber into original acoustic cloak. The low-temperature metal alloy, CerroBend, was used to microcast the metamaterial networks at a melting point of 70°C. Some damaged replicas were prepared to investigate defects in the cloak, and the performance of the broken cloak was estimated by the acoustic measurement in the water at an operating frequency of 60 kHz. We demonstrated that the broken cloak could accomplish the cloaking function depending on the direction of defects. Moreover, this study of microcasting process for the mass production and investigation of the defects in the acoustic cloak may apply to the understanding of the broken symmetric effects of an acoustic metamaterial.","Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2011-12-05T22:05:55Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 2 Cho_Shinhu.pdf.pdf: 2358472 bytes, checksum: cd9911757fc83a47d1436a55aadafbe4 (MD5) Cho_Shinhu.pdf: 2358472 bytes, checksum: cd9911757fc83a47d1436a55aadafbe4 (MD5)","Made available in DSpace on 2012-02-06T20:18:20Z (GMT). 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This micromold process with trichlorosilane was also demonstrated by casting silicone rubber into original acoustic cloak. The low-temperature metal alloy, CerroBend, was used to microcast the metamaterial networks at a melting point of 70°C. Some damaged replicas were prepared to investigate defects in the cloak, and the performance of the broken cloak was estimated by the acoustic measurement in the water at an operating frequency of 60 kHz. We demonstrated that the broken cloak could accomplish the cloaking function depending on the direction of defects. Moreover, this study of microcasting process for the mass production and investigation of the defects in the acoustic cloak may apply to the understanding of the broken symmetric effects of an acoustic metamaterial.","Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2011-12-05T22:05:55Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 2 Cho_Shinhu.pdf.pdf: 2358472 bytes, checksum: cd9911757fc83a47d1436a55aadafbe4 (MD5) Cho_Shinhu.pdf: 2358472 bytes, checksum: cd9911757fc83a47d1436a55aadafbe4 (MD5)","Made available in DSpace on 2012-02-06T20:18:20Z (GMT). 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