{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/72861"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/72861","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Stick-slip behavior of liquid droplets on pillar-arrayed PDMS surfaces","abstract":"How the roughness of a solid impacts its wettability has been of long time interest. When a droplet moves on a rough surface, it usually undergoes a stick-slip motion. However, this phenomenon lacks a proper explanation with micro-level details and analysis. . In this study, a series of experiments were conducted to monitor the contact line (CL) evolution and resistant force over time when moving droplets over micropillar pattened surfaces. MATLAB programs were developed to analyze both force and image data. Four parameters are found to have strong correlation with a droplet’s stick-slip behavior: pillar array spacing, droplet moving velocity, liquid surface tension, and droplet volume. Further study at the CL evolution images and force-time curve revealed that the stick-slip phenomenon is synchronized with pillar pinning and depinning at the CL. The evidence of liquid residues on pillars left by passing droplet supports the hypothesis of micro-capillary bridges formation and rupture, which could be a dominant mechanism governing the stick-slip behavior of moving droplets.","abstract_html":"How the roughness of a solid impacts its wettability has been of long time interest. When a droplet moves on a rough surface, it usually undergoes a stick-slip motion. However, this phenomenon lacks a proper explanation with micro-level details and analysis. . In this study, a series of experiments were conducted to monitor the contact line (CL) evolution and resistant force over time when moving droplets over micropillar pattened surfaces. MATLAB programs were developed to analyze both force and image data. Four parameters are found to have strong correlation with a droplet’s stick-slip behavior: pillar array spacing, droplet moving velocity, liquid surface tension, and droplet volume. Further study at the CL evolution images and force-time curve revealed that the stick-slip phenomenon is synchronized with pillar pinning and depinning at the CL. The evidence of liquid residues on pillars left by passing droplet supports the hypothesis of micro-capillary bridges formation and rupture, which could be a dominant mechanism governing the stick-slip behavior of moving droplets.","abstract_has_math":false,"creators":["Wei, Xian"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Mechanical Engineering","degree_department":null,"school":null,"contributors":["Hsia, K. Jimmy"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-01-21T19:48:55Z","date_published":"2015-01-21T19:48:55Z","updated_at":"2026-07-22T22:26:07Z","subjects":["Stick-Slip","Hydrophobic","Micropattern"],"languages":["en"],"rights":["Copyright 2014 Xian Wei"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/72861","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Hsia, K. Jimmy"]},{"key":"dc:creator","label":"Author","values":["Wei, Xian"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2015-01-21T19:48:55Z","2014-12","2015-01-21"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mechanical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"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":["Stick-Slip","Hydrophobic","Micropattern"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2014 Xian Wei"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/72861"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["How the roughness of a solid impacts its wettability has been of long time interest. When a droplet moves on a rough surface, it usually undergoes a stick-slip motion. However, this phenomenon lacks a proper explanation with micro-level details and analysis. . In this study, a series of experiments were conducted to monitor the contact line (CL) evolution and resistant force over time when moving droplets over micropillar pattened surfaces. MATLAB programs were developed to analyze both force and image data. Four parameters are found to have strong correlation with a droplet’s stick-slip behavior: pillar array spacing, droplet moving velocity, liquid surface tension, and droplet volume. Further study at the CL evolution images and force-time curve revealed that the stick-slip phenomenon is synchronized with pillar pinning and depinning at the CL. The evidence of liquid residues on pillars left by passing droplet supports the hypothesis of micro-capillary bridges formation and rupture, which could be a dominant mechanism governing the stick-slip behavior of moving droplets.","Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2014-12-12T14:36:15Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 1 Xian Wei_Master_Thesis_2014.pdf: 1802425 bytes, checksum: 73a0502e7b2c2f624fae887291462f7d (MD5)","Made available in DSpace on 2015-01-21T19:48:55Z (GMT). No. of bitstreams: 1 Xian_Wei.pdf: 1802425 bytes, checksum: 73a0502e7b2c2f624fae887291462f7d (MD5)"]},{"key":"dc:title","label":"Title","values":["Stick-slip behavior of liquid droplets on pillar-arrayed PDMS surfaces"]}]}],"canonical_facts":{"dc:contributor":["Hsia, K. Jimmy"],"dc:creator":["Wei, Xian"],"dc:date":["2015-01-21T19:48:55Z","2014-12","2015-01-21"],"dc:description":["How the roughness of a solid impacts its wettability has been of long time interest. When a droplet moves on a rough surface, it usually undergoes a stick-slip motion. However, this phenomenon lacks a proper explanation with micro-level details and analysis. . In this study, a series of experiments were conducted to monitor the contact line (CL) evolution and resistant force over time when moving droplets over micropillar pattened surfaces. MATLAB programs were developed to analyze both force and image data. Four parameters are found to have strong correlation with a droplet’s stick-slip behavior: pillar array spacing, droplet moving velocity, liquid surface tension, and droplet volume. Further study at the CL evolution images and force-time curve revealed that the stick-slip phenomenon is synchronized with pillar pinning and depinning at the CL. The evidence of liquid residues on pillars left by passing droplet supports the hypothesis of micro-capillary bridges formation and rupture, which could be a dominant mechanism governing the stick-slip behavior of moving droplets.","Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2014-12-12T14:36:15Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 1 Xian Wei_Master_Thesis_2014.pdf: 1802425 bytes, checksum: 73a0502e7b2c2f624fae887291462f7d (MD5)","Made available in DSpace on 2015-01-21T19:48:55Z (GMT). No. of bitstreams: 1 Xian_Wei.pdf: 1802425 bytes, checksum: 73a0502e7b2c2f624fae887291462f7d (MD5)"],"dc:identifier":["http://hdl.handle.net/2142/72861"],"dc:language":["en"],"dc:rights":["Copyright 2014 Xian Wei"],"dc:subject":["Stick-Slip","Hydrophobic","Micropattern"],"dc:title":["Stick-slip behavior of liquid droplets on pillar-arrayed PDMS surfaces"],"dc:type":["text"],"thesis:degree_discipline":["Mechanical Engineering"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["M.S."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:26:07Z"}