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Joel E. Schindall. D'Asaro, Matthew E. (Matthew Eric) Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science. Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science 2012-12-13T18:49:39Z 2012-12-13T18:49:39Z 2012 2012 http://hdl.handle.net/1721.1/75655 818357546 Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012. Cataloged from PDF version of thesis. Includes bibliographical references (p. 67-68). Electrolytic capacitors, the current standard for high-value capacitors, are one of the most challenging components to miniaturize, accounting for up to 1/3 of the volume in some power devices, and are the weak link with regard to reliability, accounting for the majority of failures in consumer electronics. As a potential alternative vertically aligned carbon nanotubes are utilized to create miniature high-speed ultracapacitors. Because the nanotubes are grown on silicon using low pressure chemical vapor deposition, this technique also opens the possibility of high-value integrated (on-die) capacitors. Using this technique a capacitance density of 52 [mu]F/mm2 was achieved. Separately, through careful design of the electrode geometry it is demonstrated that the ionic resistance, the primary factor responsible for the long time constant of ultracapacitors, scales approximately linearly with electrode finger width, thereby demonstrating a workable method for making miniature high-speed ultracapacitors. This work represents the first known example of controlling an ultracapacitor time constant purely though modification of the mechanical structure of the electrodes. It is further projected that using advanced lithography and growth techniques this speed could be increased to 120 Hz. Finally, a variety of packaging techniques are examined for both integrated and discrete applications of this technology. by Matthew E. D'Asaro. S.M. 111 p. eng Massachusetts Institute of Technology M.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. http://dspace.mit.edu/handle/1721.1/7582 Electrical Engineering and Computer Science. Design of a miniature high-speed carbon-nanotube-enhanced ultracapacitor for electronics applications Thesis application/pdf Publication unknown unknown <Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="60616f80-3a8a-4e22-87c9-c0658bfd43a3"> <Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843</Type> <Language>eng</Language> <Title>Design of a miniature high-speed carbon-nanotube-enhanced ultracapacitor for electronics applications</Title> <PublishedIn> <Publication> </Publication> </PublishedIn> <PublicationDate>2012</PublicationDate> <Authors> <Author> <DisplayName>D&apos;Asaro, Matthew E. (Matthew Eric)</DisplayName> <Affiliation> <OrgUnit> </OrgUnit> </Affiliation> </Author> </Authors> <Editors> </Editors> <Publishers> <Publisher> <DisplayName>Massachusetts Institute of Technology</DisplayName> <OrgUnit /> </Publisher> </Publishers> <License>http://dspace.mit.edu/handle/1721.1/7582</License> <Keyword>Electrical Engineering and Computer Science.</Keyword> <Abstract>Electrolytic capacitors, the current standard for high-value capacitors, are one of the most challenging components to miniaturize, accounting for up to 1/3 of the volume in some power devices, and are the weak link with regard to reliability, accounting for the majority of failures in consumer electronics. As a potential alternative vertically aligned carbon nanotubes are utilized to create miniature high-speed ultracapacitors. Because the nanotubes are grown on silicon using low pressure chemical vapor deposition, this technique also opens the possibility of high-value integrated (on-die) capacitors. Using this technique a capacitance density of 52 [mu]F/mm2 was achieved. Separately, through careful design of the electrode geometry it is demonstrated that the ionic resistance, the primary factor responsible for the long time constant of ultracapacitors, scales approximately linearly with electrode finger width, thereby demonstrating a workable method for making miniature high-speed ultracapacitors. This work represents the first known example of controlling an ultracapacitor time constant purely though modification of the mechanical structure of the electrodes. It is further projected that using advanced lithography and growth techniques this speed could be increased to 120 Hz. Finally, a variety of packaging techniques are examined for both integrated and discrete applications of this technology.</Abstract> <Access xmlns="http://purl.org/coar/access_right" > </Access> </Publication>