{"id":{"repo_id":"buffalo","oai_identifier":"oai:ubir.buffalo.edu:10477/86660"},"canonical_url":"https://search.dev.ndltd.org/etd/buffalo/oai:ubir.buffalo.edu:10477/86660","repository":{"repo_id":"buffalo","name":"Buffalo","base_url":"https://ubir.buffalo.edu/oai/request"},"display":{"title":"The Study of Vacuum-Driven Microfluidic Networks and Their Pumping Methods","abstract":"Ph.D.","abstract_html":"Ph.D.","abstract_has_math":false,"creators":["Wang, Anyang; 0000-0003-1897-8915"],"institution":"State University of New York at Buffalo","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Oh, Kwang","Electrical Engineering"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2025,"date_issued":"2025-02-21T21:36:11Z","date_published":"2025-02-21T21:36:11Z","updated_at":"2026-07-27T19:05:34Z","subjects":["electrical engineering","biomedical engineering"],"languages":["eng"],"rights":["Users of works found in University at Buffalo Institutional Repository (UBIR) are responsible for identifying and contacting the copyright owner for permission to reuse. University at Buffalo Libraries do not manage rights for copyright-protected works and cannot assist with permissions.","Copyright retained by author."],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/10477/86660","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Oh, Kwang","Electrical Engineering"]},{"key":"dc:creator","label":"Author","values":["Wang, Anyang; 0000-0003-1897-8915"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2025-02-21T21:36:11Z","2020"]},{"key":"dc:publisher","label":"Institution","values":["State University of New York at Buffalo"]},{"key":"dc:type","label":"Dc Type","values":["Text","Dissertation"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["electrical engineering","biomedical engineering"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Users of works found in University at Buffalo Institutional Repository (UBIR) are responsible for identifying and contacting the copyright owner for permission to reuse. University at Buffalo Libraries do not manage rights for copyright-protected works and cannot assist with permissions.","Copyright retained by author."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/10477/86660"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Ph.D.","The object of this thesis is to study the vacuum-driven microfluidic networks and their pumping methods for sample preparation and potential application in point-of-care testing. The components used in the vacuum-driven microfluidics are studied to understand how to design microfluidic networks using vacuum-driven pumping. Vacuum-driven microfluidic platform delivers the sample using the vacuum-driven micropumping, which requires no external pumps and no real-time control while sample flowing, so called passive pumping. The sample is delivered along the channel due to the generated pressure difference across the liquid column. One approach in vacuum-driven micropumping is to utilize the gas solubility of poly-dimethylsiloxane (PDMS). PDMS is one of the most widely used materials in microfluidic devices, and it has gas solubility high enough to utilize as a micropumping. The gas concentration inside the PDMS is subject to the ambient gas condition. For instance, the degassed PDMS can reabsorb the gas molecules from the ambient if the PDMS is returned to the atmospheric pressure under the room temperature with an ample area. In microfluidic devices, the PDMS reabsorbs the gas molecules from the ambient microchannel, making the pressure inside the dead-end channel being lower pressure than atmospheric pressure. Another approach is to utilize the gas-permeability of PDMS. Thin membrane of PDMS can transmit the gas molecules across it when a pressure difference exists across this membrane. Combine the components such as valves, mixing functions, sample preparation can be achieved in vacuum-driven microfluidic platform. First, a compact vacuum-driven micropumping usable for conventional microfluidic platforms was introduced. A small PDMS slab with a thin membrane was designed for utilizing gas permeability of PDMS. The pump can be used by simply bonding to the outlet of microfluidic channels. A constant flow with a rate ranging from 0.8 〖[nls〗^(-1)] to 7.5 〖[nls〗^(-1)] was achieved by adjusting the PDMS wall thickness and the diffusion. In addition, a gas pressure inside the microchannel was discussed using ideal gas law. Second, microvalve designs were studied to achieve sequential sample injection with temporary stop valve and retention valves. Inherent problems of inlet pressure difference effect on backflow phenomenon in passive pumpings were discussed. Utilizing backflow for potential immunoassay applications was introduced. Third, a combination of vacuum-driven micropumping with other micropumping methods, centrifugal pumping was studied. Two applications were studied. First, recirculation of sample inside the chamber concept was studied. Switching two types of actuation methods were discussed. The goal is to achieve a high success rate of detection for potential ELISA (enzyme-linked immunosorbent assay) application, which is left as a future work. In addition, a serial dilution scheme was proposed. Quantitative real time PCR was performed to evaluate ten-fold serial dilution series. The operation time of the proposed device can be ~ 45 min. while this can be shortened by several approaches such as surface coatings. The linearity of the proposed device can achieve R^2>0.99, which is comparable to the manual preparation. Lastly, studies were summarized, and future works to achieve point-of-care testing application were discussed. The vacuum-driven microfluidic platform can be useful in many applications such as sample preparation, disease screening test.","**To request an accessible version of the file(s) associated with this item, contact library@buffalo.edu. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.**"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["The Study of Vacuum-Driven Microfluidic Networks and Their Pumping Methods"]}]}],"canonical_facts":{"dc:contributor":["Oh, Kwang","Electrical Engineering"],"dc:creator":["Wang, Anyang; 0000-0003-1897-8915"],"dc:date":["2025-02-21T21:36:11Z","2020"],"dc:description":["Ph.D.","The object of this thesis is to study the vacuum-driven microfluidic networks and their pumping methods for sample preparation and potential application in point-of-care testing. The components used in the vacuum-driven microfluidics are studied to understand how to design microfluidic networks using vacuum-driven pumping. Vacuum-driven microfluidic platform delivers the sample using the vacuum-driven micropumping, which requires no external pumps and no real-time control while sample flowing, so called passive pumping. The sample is delivered along the channel due to the generated pressure difference across the liquid column. One approach in vacuum-driven micropumping is to utilize the gas solubility of poly-dimethylsiloxane (PDMS). PDMS is one of the most widely used materials in microfluidic devices, and it has gas solubility high enough to utilize as a micropumping. The gas concentration inside the PDMS is subject to the ambient gas condition. For instance, the degassed PDMS can reabsorb the gas molecules from the ambient if the PDMS is returned to the atmospheric pressure under the room temperature with an ample area. In microfluidic devices, the PDMS reabsorbs the gas molecules from the ambient microchannel, making the pressure inside the dead-end channel being lower pressure than atmospheric pressure. Another approach is to utilize the gas-permeability of PDMS. Thin membrane of PDMS can transmit the gas molecules across it when a pressure difference exists across this membrane. Combine the components such as valves, mixing functions, sample preparation can be achieved in vacuum-driven microfluidic platform. First, a compact vacuum-driven micropumping usable for conventional microfluidic platforms was introduced. A small PDMS slab with a thin membrane was designed for utilizing gas permeability of PDMS. The pump can be used by simply bonding to the outlet of microfluidic channels. A constant flow with a rate ranging from 0.8 〖[nls〗^(-1)] to 7.5 〖[nls〗^(-1)] was achieved by adjusting the PDMS wall thickness and the diffusion. In addition, a gas pressure inside the microchannel was discussed using ideal gas law. Second, microvalve designs were studied to achieve sequential sample injection with temporary stop valve and retention valves. Inherent problems of inlet pressure difference effect on backflow phenomenon in passive pumpings were discussed. Utilizing backflow for potential immunoassay applications was introduced. Third, a combination of vacuum-driven micropumping with other micropumping methods, centrifugal pumping was studied. Two applications were studied. First, recirculation of sample inside the chamber concept was studied. Switching two types of actuation methods were discussed. The goal is to achieve a high success rate of detection for potential ELISA (enzyme-linked immunosorbent assay) application, which is left as a future work. In addition, a serial dilution scheme was proposed. Quantitative real time PCR was performed to evaluate ten-fold serial dilution series. The operation time of the proposed device can be ~ 45 min. while this can be shortened by several approaches such as surface coatings. The linearity of the proposed device can achieve R^2>0.99, which is comparable to the manual preparation. Lastly, studies were summarized, and future works to achieve point-of-care testing application were discussed. The vacuum-driven microfluidic platform can be useful in many applications such as sample preparation, disease screening test.","**To request an accessible version of the file(s) associated with this item, contact library@buffalo.edu. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.**"],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/10477/86660"],"dc:language":["eng"],"dc:publisher":["State University of New York at Buffalo"],"dc:rights":["Users of works found in University at Buffalo Institutional Repository (UBIR) are responsible for identifying and contacting the copyright owner for permission to reuse. University at Buffalo Libraries do not manage rights for copyright-protected works and cannot assist with permissions.","Copyright retained by author."],"dc:subject":["electrical engineering","biomedical engineering"],"dc:title":["The Study of Vacuum-Driven Microfluidic Networks and Their Pumping Methods"],"dc:type":["Text","Dissertation"]},"updated_at":"2026-07-27T19:05:34Z"}