{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/78280"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/78280","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Nanolaminate coatings to improve long-term stability of plasmonic structures in physiological environments","abstract":"The unprecedented ability of plasmonic metal nano-structures to concentrate light into deep-subwavelength volumes has propelled their use in a vast array of nanophotonics technologies and research endeavors. They are used in sensing, super-resolution imaging, SPP lithography, SPP assisted absorption, SPP-based antennas, light manipulation, etc. To take full advantage of the attractive capabilities of CMOS compatible low-cost plasmonic structures based on Al and Cu, nanolaminate coatings are investigated to improve their long-term stability in corrosive physiological environments. The structures are fabricated using phase-shifting PDMS masks, e-beam deposition, RIE, Atomic Layer Deposition and Rapid Thermal Annealing. An alternate approach using Nanosphere Lithography (NSL) was also investigated. Films were examined using ellipsometry, atomic force microscopy and transmission measurements. Accelerated in-situ tests of Hafnium Oxide/Aluminum Oxide nanolaminate shells in a mildly pH environment with temperatures akin to physiological environments emulated using PBS show greatly enhanced endurance, with stable structures that last for more than one year.","abstract_html":"The unprecedented ability of plasmonic metal nano-structures to concentrate light into deep-subwavelength volumes has propelled their use in a vast array of nanophotonics technologies and research endeavors. They are used in sensing, super-resolution imaging, SPP lithography, SPP assisted absorption, SPP-based antennas, light manipulation, etc. To take full advantage of the attractive capabilities of CMOS compatible low-cost plasmonic structures based on Al and Cu, nanolaminate coatings are investigated to improve their long-term stability in corrosive physiological environments. The structures are fabricated using phase-shifting PDMS masks, e-beam deposition, RIE, Atomic Layer Deposition and Rapid Thermal Annealing. An alternate approach using Nanosphere Lithography (NSL) was also investigated. Films were examined using ellipsometry, atomic force microscopy and transmission measurements. Accelerated in-situ tests of Hafnium Oxide/Aluminum Oxide nanolaminate shells in a mildly pH environment with temperatures akin to physiological environments emulated using PBS show greatly enhanced endurance, with stable structures that last for more than one year.","abstract_has_math":false,"creators":["Daniel, Monisha Gnanachandra"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Electrical Engineering","degree_department":"Electrical and Computer Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Zhou, Wei"],"committee_members":["Hsiao, Michael S.","Stilwell, Daniel J."],"year":2017,"date_issued":"2017-06-28","date_published":"2017-06-28","updated_at":"2026-07-22T22:20:16Z","subjects":["Aluminum Oxide / Hafnium Oxide Nanolaminate Coatings","Atomic Layer Deposition","Plasmonics","In-situ Testing","Stability Improvement"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:11571"],"render_values":[{"text":"vt_gsexam:11571","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/78280","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Zhou, Wei"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Hsiao, Michael S.","Stilwell, Daniel J."]},{"key":"dc:contributor.department","label":"Department","values":["Electrical and Computer Engineering"]},{"key":"dc:creator","label":"Author","values":["Daniel, Monisha Gnanachandra"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2017-06-29T08:01:03Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2017-06-29T08:01:03Z"]},{"key":"dc:date.issued","label":"Date","values":["2017-06-28"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Electrical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Aluminum Oxide / Hafnium Oxide Nanolaminate Coatings","Atomic Layer Deposition","Plasmonics","In-situ Testing","Stability Improvement"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:11571"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/78280"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The unprecedented ability of plasmonic metal nano-structures to concentrate light into deep-subwavelength volumes has propelled their use in a vast array of nanophotonics technologies and research endeavors. They are used in sensing, super-resolution imaging, SPP lithography, SPP assisted absorption, SPP-based antennas, light manipulation, etc. To take full advantage of the attractive capabilities of CMOS compatible low-cost plasmonic structures based on Al and Cu, nanolaminate coatings are investigated to improve their long-term stability in corrosive physiological environments. The structures are fabricated using phase-shifting PDMS masks, e-beam deposition, RIE, Atomic Layer Deposition and Rapid Thermal Annealing. An alternate approach using Nanosphere Lithography (NSL) was also investigated. Films were examined using ellipsometry, atomic force microscopy and transmission measurements. Accelerated in-situ tests of Hafnium Oxide/Aluminum Oxide nanolaminate shells in a mildly pH environment with temperatures akin to physiological environments emulated using PBS show greatly enhanced endurance, with stable structures that last for more than one year."]},{"key":"dc:description.abstractgeneral","label":"General Abstract","values":["When light (electromagnetic radiation) interacts with the free (conduction) electrons of a metallic nanostructure it leads to a coupling resulting in collective excitations (oscillations) that lead to strong enhancements of the local electromagnetic fields surrounding the nanoparticles, this phenomenon is called Localized Surface Plasmon Resonance (LSPR) and plasmonics are structures that are capable of exhibiting this phenomenon. The condition for LSPR to occur is that the dimension scale of the structure is less than the wavelength of the electromagnetic radiation interacting with it. This implies that the structure has to be in nanoscale dimensions. LSPR based plasmonic structures are compact, sensitive and can be integrated with electronic devices and can be used in various applications like implantable biological sensors (blood pH sensing, diabetics sensing, etc.), devices that integrate several laboratory testing functionalities on a single chip, studies to determine the dynamics of chemical reactions, increasing the efficiency of solar power generation, etc. LSPR is exhibited by metallic nano-particles like gold, silver, copper and aluminum. Metals like copper corrode at a rapid rate in water at room temperature and hence nano scale structures made from them that can exhibit LSPR cannot be used in higher temperature ionic environments without a protective coating. High density, uniform coatings with less defect density can be deposited using Atomic layer deposition (ALD). In this research Atomic Layer Deposited Aluminum Oxide and Hafnium Oxide nanolaminate structures are explored to increase the long-term stability of plasmonic structures in physiological solutions. In-situ tests are carried out in a Phosphate-buffered Saline (PBS) solution with a pH value of 7.2 (simulating physiological conditions) at a temperature of 37℃ (physiological temperature) and 85.1℃ (accelerated testing). The results demonstrate that the dielectric nano coatings investigated in this project can increase the stability of the plasmonic structures in the corrosive physiological environment from a few days to more than one year."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["ETD"]},{"key":"dc:title","label":"Title","values":["Nanolaminate coatings to improve long-term stability of plasmonic structures in physiological environments"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Zhou, Wei"],"dc:contributor.committeemember":["Hsiao, Michael S.","Stilwell, Daniel J."],"dc:contributor.department":["Electrical and Computer Engineering"],"dc:creator":["Daniel, Monisha Gnanachandra"],"dc:date.accessioned":["2017-06-29T08:01:03Z"],"dc:date.available":["2017-06-29T08:01:03Z"],"dc:date.issued":["2017-06-28"],"dc:description.abstract":["The unprecedented ability of plasmonic metal nano-structures to concentrate light into deep-subwavelength volumes has propelled their use in a vast array of nanophotonics technologies and research endeavors. They are used in sensing, super-resolution imaging, SPP lithography, SPP assisted absorption, SPP-based antennas, light manipulation, etc. To take full advantage of the attractive capabilities of CMOS compatible low-cost plasmonic structures based on Al and Cu, nanolaminate coatings are investigated to improve their long-term stability in corrosive physiological environments. The structures are fabricated using phase-shifting PDMS masks, e-beam deposition, RIE, Atomic Layer Deposition and Rapid Thermal Annealing. An alternate approach using Nanosphere Lithography (NSL) was also investigated. Films were examined using ellipsometry, atomic force microscopy and transmission measurements. Accelerated in-situ tests of Hafnium Oxide/Aluminum Oxide nanolaminate shells in a mildly pH environment with temperatures akin to physiological environments emulated using PBS show greatly enhanced endurance, with stable structures that last for more than one year."],"dc:description.abstractgeneral":["When light (electromagnetic radiation) interacts with the free (conduction) electrons of a metallic nanostructure it leads to a coupling resulting in collective excitations (oscillations) that lead to strong enhancements of the local electromagnetic fields surrounding the nanoparticles, this phenomenon is called Localized Surface Plasmon Resonance (LSPR) and plasmonics are structures that are capable of exhibiting this phenomenon. The condition for LSPR to occur is that the dimension scale of the structure is less than the wavelength of the electromagnetic radiation interacting with it. This implies that the structure has to be in nanoscale dimensions. LSPR based plasmonic structures are compact, sensitive and can be integrated with electronic devices and can be used in various applications like implantable biological sensors (blood pH sensing, diabetics sensing, etc.), devices that integrate several laboratory testing functionalities on a single chip, studies to determine the dynamics of chemical reactions, increasing the efficiency of solar power generation, etc. LSPR is exhibited by metallic nano-particles like gold, silver, copper and aluminum. Metals like copper corrode at a rapid rate in water at room temperature and hence nano scale structures made from them that can exhibit LSPR cannot be used in higher temperature ionic environments without a protective coating. High density, uniform coatings with less defect density can be deposited using Atomic layer deposition (ALD). In this research Atomic Layer Deposited Aluminum Oxide and Hafnium Oxide nanolaminate structures are explored to increase the long-term stability of plasmonic structures in physiological solutions. In-situ tests are carried out in a Phosphate-buffered Saline (PBS) solution with a pH value of 7.2 (simulating physiological conditions) at a temperature of 37℃ (physiological temperature) and 85.1℃ (accelerated testing). The results demonstrate that the dielectric nano coatings investigated in this project can increase the stability of the plasmonic structures in the corrosive physiological environment from a few days to more than one year."],"dc:description.degree":["Master of Science"],"dc:format.medium":["ETD"],"dc:identifier.other":["vt_gsexam:11571"],"dc:identifier.uri":["http://hdl.handle.net/10919/78280"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Aluminum Oxide / Hafnium Oxide Nanolaminate Coatings","Atomic Layer Deposition","Plasmonics","In-situ Testing","Stability Improvement"],"dc:title":["Nanolaminate coatings to improve long-term stability of plasmonic structures in physiological environments"],"dc:type":["Thesis"],"thesis:degree_discipline":["Electrical Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:20:16Z"}