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dc.contributor.authorDerryberry, Rebekah Annen_US
dc.date.accessioned2014-03-14T20:33:49Z
dc.date.available2014-03-14T20:33:49Z
dc.date.issued2007-04-05en_US
dc.identifier.otheretd-04182007-105942en_US
dc.identifier.urihttp://hdl.handle.net/10919/31758
dc.description.abstractThermoelectric phenomenon describes the relationship between the flow of heat and electricity. Two main categories encompassed in thermoelectric theory are the Seebeck and Peltier effects. The Seebeck effect is the generation of a voltage in a device that consists of two different materials in the presence of a temperature gradient, while the Peltier effect is the generation of a temperature gradient across a device of two different materials in the presence of an electrical current. This project focuses on the first of these two phenomena, where the Seebeck effect is used in a novel heat flux sensor that is transverse in nature. Transverse thermoelectric devices are characterized by their anisotropy, meaning that a temperature gradient generated across a device will be perpendicular to the flow of electricity through the device. This orthogonal arrangement allows for the manipulation of material properties, device arrangement, and construction methods for device optimization. This project characterizes the heat flux sensing capabilities of an artificially anisotropic transverse thermoelectric device via experimental and theoretical methods. The device tested is constructed out of bismuth telluride and titanium grade 5. Bismuth telluride is a standard thermoelectric material, while the titanium is used because of its high melting point and good electrical conductivity. The device is constructed by alternating rectangular pieces of these two materials. These pieces are bonded together at a given angle to simulate anisotropy. Several devices are constructed in a range of angles from 59 to 88°. These devices are each tested in a vacuum chamber where a heater heats one side of the device. This heat flux into the device creates a temperature gradient across the device and the device generates a voltage perpendicular to this temperature gradient. Steady state data are collected for both the temperature difference between the two sides of the device and the voltage generated by the device. This procedure is repeated on each device for a range of heat fluxes from 0 to 2.6 W/cm2. This range generates voltage signals up to 14341 µV for an angle of 59°. Data collected are then used to generate a linear trend line that describes the devices response to a given heat flux. These experimental results are compared to theoretical predictions using thermoelectric theory. The results indicate that the device does exhibit transverse thermoelectric characteristics and the experimental data follow the predicted trends. This thesis documents the process of constructing, testing, and analyzing this device.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartDerryberry.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.subjectbismuth tellurideen_US
dc.subjectsemiconductoren_US
dc.subjectheat flux sensingen_US
dc.subjecttransverse thermoelectricsen_US
dc.subjectThomson effecten_US
dc.subjectPeltieren_US
dc.subjectSeebecken_US
dc.subjectanisotropyen_US
dc.titleArtificial Anisotropy for Transverse Thermoelectric Heat Flux Sensingen_US
dc.typeThesisen_US
dc.contributor.departmentMechanical Engineeringen_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.disciplineMechanical Engineeringen_US
dc.contributor.committeechairHuxtable, Scott T.en_US
dc.contributor.committeememberPaul, Mark R.en_US
dc.contributor.committeememberDiller, Thomas E.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-04182007-105942/en_US
dc.date.sdate2007-04-18en_US
dc.date.rdate2007-04-24
dc.date.adate2007-04-24en_US


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