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dc.contributor.advisorMcCluskey, F. Patricken_US
dc.contributor.authorJain, Rupalen_US
dc.date.accessioned2008-04-22T16:01:42Z
dc.date.available2008-04-22T16:01:42Z
dc.date.issued2007-09-28en_US
dc.identifier.urihttp://hdl.handle.net/1903/7605
dc.description.abstractA novel acoustic sensor incorporating cilia-like nanowires made of magnetostrictive iron-gallium (Galfenol) alloy has been designed and fabricated using micromachining techniques. The sensor and its package design are analogous to the structural design and the transduction process of a human-ear cochlea. The nanowires are sandwiched between a flexible membrane and a fixed membrane similar to the cilia between basilar and tectorial membranes in the cochlea. The stress induced in the nanowires due to the motion of the flexible membrane in response to acoustic waves results in a change in the magnetic flux in the nanowires. These changes in the magnetic flux are converted into electrical voltage changes by a GMR (giant magnetoresistive) sensor. As the acoustic sensor is designed for underwater applications, packaging is a key issue for the effective working of this sensor. A good package should provide a suitably protective environment to the sensor, while allowing sound waves to reach the sensing element with a minimal attenuation. In this thesis, design efforts aimed at producing this MEMS bio-inspired acoustic transducer have been detailed along with the process sequence for its fabrication. Package materials including encapsulants and filler fluids have been identified based on their acoustic performance in water by conducting several experiments to compare their impedance and attenuation characteristics and moisture absorption properties. Preliminary test results of the sensor without nanowires demonstrate the process is practical for constructing a nanowire based acoustic sensor, yielding potential benefits for SONAR applications and hearing implants.en_US
dc.format.extent5940867 bytes
dc.format.mimetypeapplication/pdf
dc.language.isoen_US
dc.titleDesign and packaging of an iron-gallium (Galfenol) nanowire acoustic sensor for underwater applicationsen_US
dc.typeThesisen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.contributor.departmentMechanical Engineeringen_US
dc.subject.pqcontrolledEngineering, Mechanicalen_US
dc.subject.pquncontrolledpackagingen_US
dc.subject.pquncontrollednanowiresen_US
dc.subject.pquncontrolledacoustic sensoren_US
dc.subject.pquncontrolledunderwateren_US
dc.subject.pquncontrolledMEMS;en_US


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