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dc.contributor.authorChoudhury, Uditen_US
dc.date.accessioned2014-03-14T21:28:15Z
dc.date.available2014-03-14T21:28:15Z
dc.date.issued2012-01-23en_US
dc.identifier.otheretd-01312012-161014en_US
dc.identifier.urihttp://hdl.handle.net/10919/40869
dc.description.abstractResilin is a cuticular protein found in a variety of insects. It can stretch up to 300% of its natural length without any creep or relaxation. Further, it operates across a wide frequency range from 5 Hz in locomotion to 13 kHz in sound production. Both the protein sequence and composition of natural resilin as well as the dynamic mechanical properties vary substantially across species. This suggests that mechanical properties may be evolutionarily tuned for specific functions within an insect. Here, samples of resilin obtained from the tibia-tarsal joint of the cockroach, Periplaneta americana, were tested using a custom built dynamic mechanical analyzer. The material properties in compression are obtained from the rubbery to glassy domain with time-temperature superposition (-2C to 55C) and time-concentration superposition (0 % to 93% ethanol by volume in water). At low frequency the storage modulus was found to be 1.5 MPa increasing to about 5 MPa in the transition zone. The glass transition frequency at 23C in complete hydration was found to be 200 kHz. The data shows that cockroach resilin is less resilient than dragonfly resilin at low frequencies, returning about 79% of the elastic strain energy at 25 Hz compared to 97% for dragonfly resilin. However, at the glass transition (200 kHz) the material returns about 47% of the elastic strain energy compared to 30% in dragonfly (2MHz ). The resilin pad in cockroach is a composite structure, acting as a compressive spring to passively extend the tibia-tarsal joint during cockroach locomotion. Its mechanical properties are more similar to the composite locust pre-alar arm than to the pure resilin dragonfly tendon, suggesting that macroscopic structural influences may be as important as molecular sequence differences in setting properties.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartChoudhury_U_T_2012.pdfen_US
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Virginia Tech or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectTime-Concentration Superpositionen_US
dc.subjectTime-Temperature Superpositionen_US
dc.subjectDynamic Mechanical Analysisen_US
dc.subjectBiopolymersen_US
dc.subjectResilinen_US
dc.subjectBiomaterialsen_US
dc.titleDynamic Mechanical Properties of Cockroach(Periplaneta americana) Resilinen_US
dc.typeThesisen_US
dc.contributor.departmentEngineering Science and Mechanicsen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineEngineering Science and Mechanicsen_US
dc.contributor.committeechairDudek, Daniel M.en_US
dc.contributor.committeememberLesko, John J.en_US
dc.contributor.committeememberMoore, Robert B.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-01312012-161014/en_US
dc.date.sdate2012-01-31en_US
dc.date.rdate2012-03-01
dc.date.adate2012-03-01en_US


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