{"id":{"repo_id":"glasgow","oai_identifier":"oai:theses.gla.ac.uk:1436"},"canonical_url":"https://search.dev.ndltd.org/etd/glasgow/oai:theses.gla.ac.uk:1436","repository":{"repo_id":"glasgow","name":"University of Glasgow","base_url":"https://theses.gla.ac.uk/cgi/oai2"},"display":{"title":"High-speed video microscopy in optical tweezers","abstract":"Optical tweezers have become an invaluable tool for measuring and exerting forces in the pico-Newton regime. Force measurements have in the past concentrated on using only one trapped particle as a probe, partly due to the difficulties in tracking more than one par- ticle at high enough frame rate. Recent advances in video camera technology allow the collection of images at several kHz. However, there has been little use of high-speed cameras in optical tweezers, partly due to data management problems and affordability. This the- sis presents seven experiments carried out during my PhD involving the use of several different high-speed cameras. Chapter 3 presents the use of a CMOS high-speed camera with in- tegrated particle tracking built by Durham Smart Imaging. The camera was used in a Shack-Hartmann sensor setup to determine rapidly and non-ambiguously the sign and magnitude of the orbital angular momentum of a helically-phased beam light beam, as an alternative to interferometric techniques. Chapter 4 presents a di- rect comparison of a CCD high-speed video camera with a quadrant photodiode to track particle position. Particle tracking was possible at high enough accuracy and bandwidth to allow convenient trap calibration by thermal analysis. Chapter 5 reports an investigation of the resulting change in trap stiffness during the update of trap positions in holographic optical tweezers. Chapter 6 presents the re- sults from using a high-speed camera to successfully track multiple particles in a microfluidic channel to measure the viscosity at sev- eral points simultaneously. The last three chapters investigate the hydrodynamic interactions between trapped particles under different conditions and comparisons were made with theory.","abstract_html":"Optical tweezers have become an invaluable tool for measuring and exerting forces in the pico-Newton regime. Force measurements have in the past concentrated on using only one trapped particle as a probe, partly due to the difficulties in tracking more than one par- ticle at high enough frame rate. Recent advances in video camera technology allow the collection of images at several kHz. However, there has been little use of high-speed cameras in optical tweezers, partly due to data management problems and affordability. This the- sis presents seven experiments carried out during my PhD involving the use of several different high-speed cameras. Chapter 3 presents the use of a CMOS high-speed camera with in- tegrated particle tracking built by Durham Smart Imaging. The camera was used in a Shack-Hartmann sensor setup to determine rapidly and non-ambiguously the sign and magnitude of the orbital angular momentum of a helically-phased beam light beam, as an alternative to interferometric techniques. Chapter 4 presents a di- rect comparison of a CCD high-speed video camera with a quadrant photodiode to track particle position. Particle tracking was possible at high enough accuracy and bandwidth to allow convenient trap calibration by thermal analysis. Chapter 5 reports an investigation of the resulting change in trap stiffness during the update of trap positions in holographic optical tweezers. Chapter 6 presents the re- sults from using a high-speed camera to successfully track multiple particles in a microfluidic channel to measure the viscosity at sev- eral points simultaneously. The last three chapters investigate the hydrodynamic interactions between trapped particles under different conditions and comparisons were made with theory.","abstract_has_math":false,"creators":["Keen, Stephen Alexander Juhani"],"institution":"University of Glasgow","degree_name":null,"degree_level":"PhD","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2009,"date_issued":"2009","date_published":"2009","updated_at":"2026-07-24T02:23:57Z","subjects":["QC Physics"],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":null,"outbound_label":null,"outbound_source":null},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Keen, Stephen Alexander Juhani"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2009"]},{"key":"dc:date.issued","label":"Date","values":["2009"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Glasgow"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://theses.gla.ac.uk/1436/"]},{"key":"dc:relation.isreferencedby.uri","label":"Dc Relation Isreferencedby URI","values":["https://gla.on.worldcat.org/oclc/1547496566"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["PhD"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["QC Physics"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://theses.gla.ac.uk/1436/1/2009keenphd.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Optical tweezers have become an invaluable tool for measuring and exerting forces in the pico-Newton regime. Force measurements have in the past concentrated on using only one trapped particle as a probe, partly due to the difficulties in tracking more than one par- ticle at high enough frame rate. Recent advances in video camera technology allow the collection of images at several kHz. However, there has been little use of high-speed cameras in optical tweezers, partly due to data management problems and affordability. This the- sis presents seven experiments carried out during my PhD involving the use of several different high-speed cameras. Chapter 3 presents the use of a CMOS high-speed camera with in- tegrated particle tracking built by Durham Smart Imaging. The camera was used in a Shack-Hartmann sensor setup to determine rapidly and non-ambiguously the sign and magnitude of the orbital angular momentum of a helically-phased beam light beam, as an alternative to interferometric techniques. Chapter 4 presents a di- rect comparison of a CCD high-speed video camera with a quadrant photodiode to track particle position. Particle tracking was possible at high enough accuracy and bandwidth to allow convenient trap calibration by thermal analysis. Chapter 5 reports an investigation of the resulting change in trap stiffness during the update of trap positions in holographic optical tweezers. Chapter 6 presents the re- sults from using a high-speed camera to successfully track multiple particles in a microfluidic channel to measure the viscosity at sev- eral points simultaneously. The last three chapters investigate the hydrodynamic interactions between trapped particles under different conditions and comparisons were made with theory."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["High-speed video microscopy in optical tweezers"]}]}],"canonical_facts":{"dc:creator":["Keen, Stephen Alexander Juhani"],"dc:date":["2009"],"dc:date.issued":["2009"],"dc:description.abstract":["Optical tweezers have become an invaluable tool for measuring and exerting forces in the pico-Newton regime. Force measurements have in the past concentrated on using only one trapped particle as a probe, partly due to the difficulties in tracking more than one par- ticle at high enough frame rate. Recent advances in video camera technology allow the collection of images at several kHz. However, there has been little use of high-speed cameras in optical tweezers, partly due to data management problems and affordability. This the- sis presents seven experiments carried out during my PhD involving the use of several different high-speed cameras. Chapter 3 presents the use of a CMOS high-speed camera with in- tegrated particle tracking built by Durham Smart Imaging. The camera was used in a Shack-Hartmann sensor setup to determine rapidly and non-ambiguously the sign and magnitude of the orbital angular momentum of a helically-phased beam light beam, as an alternative to interferometric techniques. Chapter 4 presents a di- rect comparison of a CCD high-speed video camera with a quadrant photodiode to track particle position. Particle tracking was possible at high enough accuracy and bandwidth to allow convenient trap calibration by thermal analysis. Chapter 5 reports an investigation of the resulting change in trap stiffness during the update of trap positions in holographic optical tweezers. Chapter 6 presents the re- sults from using a high-speed camera to successfully track multiple particles in a microfluidic channel to measure the viscosity at sev- eral points simultaneously. The last three chapters investigate the hydrodynamic interactions between trapped particles under different conditions and comparisons were made with theory."],"dc:format":["application/pdf"],"dc:identifier.uri":["https://theses.gla.ac.uk/1436/1/2009keenphd.pdf"],"dc:language":["en"],"dc:publisher.institution":["University of Glasgow"],"dc:relation.isreferencedby":["https://theses.gla.ac.uk/1436/"],"dc:relation.isreferencedby.uri":["https://gla.on.worldcat.org/oclc/1547496566"],"dc:subject":["QC Physics"],"dc:title":["High-speed video microscopy in optical tweezers"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["PhD"]},"updated_at":"2026-07-24T02:23:57Z"}