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dc.contributor.advisorAlexander H. Slocum and Themistoklis P. Sapsis.en_US
dc.contributor.authorKluger, Jocelyn Maxineen_US
dc.contributor.otherMassachusetts Institute of Technology. Department of Mechanical Engineering.en_US
dc.date.accessioned2014-06-13T22:36:33Z
dc.date.available2014-06-13T22:36:33Z
dc.date.copyright2014en_US
dc.date.issued2014en_US
dc.identifier.urihttp://hdl.handle.net/1721.1/87958
dc.descriptionThesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.en_US
dc.descriptionCataloged from PDF version of thesis.en_US
dc.descriptionIncludes bibliographical references (pages 216-218).en_US
dc.description.abstractThis thesis studies a novel nonlinear spring mechanism that is comprised of a cantilever wrapping around a curved surface as it deflects. Static force versus displacement tests and dynamic "initial displacement" tests verified the spring theory for a large range of oscillator parameters. Various human motion energy harvester configurations that use the nonlinear spring were numerically optimized for power, robustness, and adaptivity. Based on the optimization results, both the nonlinear and linear devices studied in this thesis generate more power per volume and per mass when excited at one's hip while walking than current commercial energy harvesters. The two degree-of-freedom (2DOF) nonlinear oscillator is more adaptive to different excitation signals and resistant to power decay when parasitic damping is present than the IDOF and 2DOF linear systems. These significant advantages are caused by the 2DOF nonlinear system harvesting its optimal power at large electromagnetic damping coefficients, whereas the optimal power generation for the linear systems occurs at low electromagnetic damping coefficients. This thesis also examined what electromagnetic damping coefficients can be generated by magnet-and-coil geometries that satisfy the energy harvester constraints. The final chapter of this thesis investigates a load cell that uses the stiffening spring to maintain high resolution over a large range of forces and prevent large forces from damaging the load cell. Future work will include testing a full energy harvester prototype and exploring other applications of the nonlinear spring.en_US
dc.description.statementofresponsibilityby Jocelyn Maxine Kluger.en_US
dc.format.extent218 pagesen_US
dc.language.isoengen_US
dc.publisherMassachusetts Institute of Technologyen_US
dc.rightsM.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.en_US
dc.rights.urihttp://dspace.mit.edu/handle/1721.1/7582en_US
dc.subjectMechanical Engineering.en_US
dc.titleNonlinear beam-based vibration energy harvesters and load cellsen_US
dc.typeThesisen_US
dc.description.degreeS.M.en_US
dc.contributor.departmentMassachusetts Institute of Technology. Department of Mechanical Engineering.en_US
dc.identifier.oclc880676309en_US


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