{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/108337"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/108337","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Vibrating lubricant-infused porous surface for enhanced liquid droplet transport","abstract":"Lubricant-infused porous surfaces (SLIPS) demonstrate extreme liquid repellency such that a droplet immiscible with the lubricant can roll off at a very small tilt angle < 5°. There have been many applications in using SLIPS to achieve complex fluids handling, anti-fouling, self-cleaning, anti-icing, and enhanced condensation heat transfer. In recent studies of droplet dynamics on SLIPS, it was observed that a moving droplet on the lubricant film follows lubrication theory and the Landau-Levich law — there is a zone of capillary pressure-driven flow inside the lubricant wetting ridge around the droplet base when the capillary number is much smaller than one. The viscous dissipative force, which resists this capillary suction of lubricant, depends non-linearly on the capillary number with a two-thirds power. This doctoral thesis focuses on the enhanced droplet transport on vibrating SLIPS, as well as the applications in anti-biofouling, enhanced self-cleaning and condensates heat transfer. To study oscillating droplets on SLIPS, we developed SLIPS that can be put in motion by a dielectric elastomer actuator (DEA). This system demonstrates its ability to generate tunable surface wettability that can precisely control droplet dynamics, from complete pinning to fast sliding, and even more complex motions such as droplet oscillation, jetting and mixing. Next, more detailed analysis of the synergistic effect among deforming droplet, lubricant film, and vibrating device on the fast sliding speed is discussed, in particular (i) transverse membrane velocity and resonant mode shapes of SLIPS membrane studied by laser vibrometer, and (ii) oscillatory droplet contact line dynamics studied by high-speed photography. Finally, we further demonstrate how vibrational actuation into SLIPS achieves enhanced condensate repellency and heat transfer compared to conventional repellent surfaces. Faster departing speed and smaller departing size of condensates on vibrating SLIPS were observed compared to non-vibrational SLIPS, which are crucial to enhance heat transfer during dropwise condensation. The time-averaged size distribution and temporal growth of condensates on this surface are experimentally analyzed. The roles of these unique behaviors on condensation dynamics are explained with the assist of a condensation heat transfer model.","abstract_html":"Lubricant-infused porous surfaces (SLIPS) demonstrate extreme liquid repellency such that a droplet immiscible with the lubricant can roll off at a very small tilt angle &lt; 5°. There have been many applications in using SLIPS to achieve complex fluids handling, anti-fouling, self-cleaning, anti-icing, and enhanced condensation heat transfer. In recent studies of droplet dynamics on SLIPS, it was observed that a moving droplet on the lubricant film follows lubrication theory and the Landau-Levich law — there is a zone of capillary pressure-driven flow inside the lubricant wetting ridge around the droplet base when the capillary number is much smaller than one. The viscous dissipative force, which resists this capillary suction of lubricant, depends non-linearly on the capillary number with a two-thirds power. This doctoral thesis focuses on the enhanced droplet transport on vibrating SLIPS, as well as the applications in anti-biofouling, enhanced self-cleaning and condensates heat transfer. To study oscillating droplets on SLIPS, we developed SLIPS that can be put in motion by a dielectric elastomer actuator (DEA). This system demonstrates its ability to generate tunable surface wettability that can precisely control droplet dynamics, from complete pinning to fast sliding, and even more complex motions such as droplet oscillation, jetting and mixing. Next, more detailed analysis of the synergistic effect among deforming droplet, lubricant film, and vibrating device on the fast sliding speed is discussed, in particular (i) transverse membrane velocity and resonant mode shapes of SLIPS membrane studied by laser vibrometer, and (ii) oscillatory droplet contact line dynamics studied by high-speed photography. Finally, we further demonstrate how vibrational actuation into SLIPS achieves enhanced condensate repellency and heat transfer compared to conventional repellent surfaces. Faster departing speed and smaller departing size of condensates on vibrating SLIPS were observed compared to non-vibrational SLIPS, which are crucial to enhance heat transfer during dropwise condensation. The time-averaged size distribution and temporal growth of condensates on this surface are experimentally analyzed. The roles of these unique behaviors on condensation dynamics are explained with the assist of a condensation heat transfer model.","abstract_has_math":false,"creators":["Oh, Inkyu"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Mechanical Engineering","degree_department":null,"school":null,"contributors":["Hu, Yuhang","Kong, Hyunjoon","Hilgenfeldt, Sascha","Miljkovic, Nenad"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2020,"date_issued":"2020-08-27T00:51:31Z","date_published":"2020-08-27T00:51:31Z","updated_at":"2026-07-22T22:24:48Z","subjects":["Lubricant-infused surface, Droplet control"],"languages":["en"],"rights":["Copyright 2020 Inkyu Oh"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/108337","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Hu, Yuhang","Kong, Hyunjoon","Hilgenfeldt, Sascha","Miljkovic, Nenad"]},{"key":"dc:creator","label":"Author","values":["Oh, Inkyu"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2020-08-27T00:51:31Z","2022-08-27T00:51:40Z","2020-05-08","2020-05"]},{"key":"dc:type","label":"Dc Type","values":["text","Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mechanical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Lubricant-infused surface, Droplet control"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2020 Inkyu Oh"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/108337"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Lubricant-infused porous surfaces (SLIPS) demonstrate extreme liquid repellency such that a droplet immiscible with the lubricant can roll off at a very small tilt angle < 5°. There have been many applications in using SLIPS to achieve complex fluids handling, anti-fouling, self-cleaning, anti-icing, and enhanced condensation heat transfer. In recent studies of droplet dynamics on SLIPS, it was observed that a moving droplet on the lubricant film follows lubrication theory and the Landau-Levich law — there is a zone of capillary pressure-driven flow inside the lubricant wetting ridge around the droplet base when the capillary number is much smaller than one. The viscous dissipative force, which resists this capillary suction of lubricant, depends non-linearly on the capillary number with a two-thirds power. This doctoral thesis focuses on the enhanced droplet transport on vibrating SLIPS, as well as the applications in anti-biofouling, enhanced self-cleaning and condensates heat transfer. To study oscillating droplets on SLIPS, we developed SLIPS that can be put in motion by a dielectric elastomer actuator (DEA). This system demonstrates its ability to generate tunable surface wettability that can precisely control droplet dynamics, from complete pinning to fast sliding, and even more complex motions such as droplet oscillation, jetting and mixing. Next, more detailed analysis of the synergistic effect among deforming droplet, lubricant film, and vibrating device on the fast sliding speed is discussed, in particular (i) transverse membrane velocity and resonant mode shapes of SLIPS membrane studied by laser vibrometer, and (ii) oscillatory droplet contact line dynamics studied by high-speed photography. Finally, we further demonstrate how vibrational actuation into SLIPS achieves enhanced condensate repellency and heat transfer compared to conventional repellent surfaces. Faster departing speed and smaller departing size of condensates on vibrating SLIPS were observed compared to non-vibrational SLIPS, which are crucial to enhance heat transfer during dropwise condensation. The time-averaged size distribution and temporal growth of condensates on this surface are experimentally analyzed. The roles of these unique behaviors on condensation dynamics are explained with the assist of a condensation heat transfer model.","Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2022-05-01","The student, Inkyu Oh, accepted the attached license on 2020-05-07 at 21:15.","The student, Inkyu Oh, submitted this Dissertation for approval on 2020-05-08 at 07:14.","This Dissertation was approved for publication on 2020-05-08 at 16:54.","DSpace SAF Submission Ingestion Package generated from Vireo submission #15288 on 2020-08-25 at 17:44:13","Made available in DSpace on 2020-08-27T00:51:31Z (GMT). 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There have been many applications in using SLIPS to achieve complex fluids handling, anti-fouling, self-cleaning, anti-icing, and enhanced condensation heat transfer. In recent studies of droplet dynamics on SLIPS, it was observed that a moving droplet on the lubricant film follows lubrication theory and the Landau-Levich law — there is a zone of capillary pressure-driven flow inside the lubricant wetting ridge around the droplet base when the capillary number is much smaller than one. The viscous dissipative force, which resists this capillary suction of lubricant, depends non-linearly on the capillary number with a two-thirds power. This doctoral thesis focuses on the enhanced droplet transport on vibrating SLIPS, as well as the applications in anti-biofouling, enhanced self-cleaning and condensates heat transfer. To study oscillating droplets on SLIPS, we developed SLIPS that can be put in motion by a dielectric elastomer actuator (DEA). This system demonstrates its ability to generate tunable surface wettability that can precisely control droplet dynamics, from complete pinning to fast sliding, and even more complex motions such as droplet oscillation, jetting and mixing. Next, more detailed analysis of the synergistic effect among deforming droplet, lubricant film, and vibrating device on the fast sliding speed is discussed, in particular (i) transverse membrane velocity and resonant mode shapes of SLIPS membrane studied by laser vibrometer, and (ii) oscillatory droplet contact line dynamics studied by high-speed photography. Finally, we further demonstrate how vibrational actuation into SLIPS achieves enhanced condensate repellency and heat transfer compared to conventional repellent surfaces. Faster departing speed and smaller departing size of condensates on vibrating SLIPS were observed compared to non-vibrational SLIPS, which are crucial to enhance heat transfer during dropwise condensation. The time-averaged size distribution and temporal growth of condensates on this surface are experimentally analyzed. The roles of these unique behaviors on condensation dynamics are explained with the assist of a condensation heat transfer model.","Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2022-05-01","The student, Inkyu Oh, accepted the attached license on 2020-05-07 at 21:15.","The student, Inkyu Oh, submitted this Dissertation for approval on 2020-05-08 at 07:14.","This Dissertation was approved for publication on 2020-05-08 at 16:54.","DSpace SAF Submission Ingestion Package generated from Vireo submission #15288 on 2020-08-25 at 17:44:13","Made available in DSpace on 2020-08-27T00:51:31Z (GMT). No. of bitstreams: 2 OH-DISSERTATION-2020.pdf: 5030052 bytes, checksum: c4182ec4a70618388d16b3be262b3748 (MD5) LICENSE.txt: 4205 bytes, checksum: b659fb023226783705899eac880abbfc (MD5) Previous issue date: 2020-05-08","Embargo set by: Seth Robbins for item 115952 Lift date: 2022-08-27T00:51:40Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system","Author requested closed access (OA after 2yrs) in Vireo ETD system","Limited"],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/108337"],"dc:language":["en"],"dc:rights":["Copyright 2020 Inkyu Oh"],"dc:subject":["Lubricant-infused surface, Droplet control"],"dc:title":["Vibrating lubricant-infused porous surface for enhanced liquid droplet transport"],"dc:type":["text","Thesis"],"thesis:degree_discipline":["Mechanical Engineering"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:24:48Z"}