Beunis, Filip

Brans, Toon

Burghammer, Manfred

Janssen, Colin

Riekel, Christian

Santucci, Silvia

Vandegehuchte, Michiel

Vekemans, Bart

Vergucht, Eva

Vincze, Laszlo

English

Ghent University Academic Bibliography

Data Processing and Optical Trap Stability   Data processing is performed in Linux using IDL (Interactive Data Language)  Integrated CCD camera collects JPEG-files (every 10 seconds for 1 hour).  JPEG-files are read in and three regions of interest (ROI) are selected:    ROI 1: Position of the test object,              a silica microsphere (ø 3.5 µm) ROI 2: Position of the lower capillary wall ROI 3: Position of the laser beam    Optical trap stability study for combining SR micro/nano-XRF methods  with optical tweezers based sample manipulation Eva VERGUCHT1*, Toon BRANS², Filip BEUNIS2, Michiel VANDEGEHUCHTE3, Bart VEKEMANS1,  Silvia SANTUCCI4, Colin JANSSEN3, Manfred BURGHAMMER1,4, Christian RIEKEL4 and Laszlo VINCZE1    1. X-ray Microspectroscopy and Imaging Group (XMI), Ghent University, Krijgslaan 281 (S12), B-9000 Ghent, Belgium 2. Center for Nano and Biophotonics (NB-Photonics), Ghent University, Sint-Pietersnieuwstraat 41, B-9000 Ghent, Belgium 3. Laboratory of Environmental Toxicology and Aquatic Ecology, Jozef Plateaustraat 22, B-9000 Ghent, Belgium 4. European Synchrotron Radiation Facility (ESRF), F-38043 Grenoble, France Optical Trapping  An optical trap is a micro-manipulation tool that uses a highly-focused laser beam  to trap, move and rotate microscopic dielectric objects in three dimensions [1].  Optical trapping results from the interaction between the (IR) laser and  the refractive index mismatch of the object with its environment (e.g., water).  Scattering force:        reflection of photons at the object-medium interface  Object is pushed away from the optical trap  Gradient force:          refraction of photons at the object-medium interface  Object is attracted towards the optical trap  An object is stably optically trapped when both forces become equal in size. References Corresponding author [1]      Masters thesis ir. Steffen Tallieu, Holographic optical trapping, Ghent University, 2011-2012 [2]      Santucci, S.C., et al., Analytical Chemistry, 2011. 83(12): p. 4863-4870. *  Eva Vergucht, X-ray Microspectroscopy and Imaging Group (XMI), Department of Analytical Chemistry,  Ghent University, Krijgslaan 281 (S12), B-9000 Ghent, Belgium, Eva.Vergucht@UGent.be Abstract The goal of this project involves the development of a new methodology that combines confocal SR micro/nano X-ray fluorescence imaging (XRF) with laser-based optical tweezers (OT) for contactless sample manipulation. This new methodology will enable the investigation of biological model organisms and single cells in a state that is much closer to their natural state. Since the combination with scanning XRF analysis on the micro- and nanoscale is planned, a stability study of a test object in the optical trap is crucial. Next to the description of our compact OT setup, the results of the initial characterization of the setup are presented in terms of trapping performance along the optical axis (Z-direction) and perpendicular to the laser beam (Y- direction). Mirrors: • Manipulated for alignment 4 IR laser SLM Mirrors Dichroic mirror Trapping objective 6 5 4 3 2 Microscope trapping  objective (MO): • Focusses IR beam • 100x, Olympus • NA = 1 • Water immersion • 1 mm working distance  6 Dichroic mirror: •  reflection IR light • Transparent for visual light 5 Spatial Light Modulator (SLM): • Bi-functional: beam splitter or mirror • Control  via holograms (pc) • Hamamatsu Photonics 3 IR laser coupled with fiber optics: • λ = 1070 nm, transparent wavelength for biological samples • Beam expander in front of laser collimator • IPG Photonics 2 Start optical path (          ) 1 7 Sample area 7 1 Compact Optical Tweezers Setup  Three major components:                              +                                                                            +        Compact optical tweezers setup available from beamline ID13, ESRF [2]. Scattering force Gradient force Laser Trapping Microscope Objective Imaging system Stability in Y-direction:           Sufficient sub-micron stability.  Trapping  objective Cover glass: Interface between capillary and water Glass capillary (CTS, UK): Filled with (biological)  samples and medium 7 Al sample  holder Objective in front  of CCD CCD  camera Immersion water Z Y Mean:  2.60 ± 0.27 µm  Mean:  17.98 µm ± 1.53 µm  Stability in Z-direction: Stability in Z-direction should be improved for performing micro/nano XRF analysis. Capillary wall Focussed laser beam Optically trapped  silica microsphere Z Y ROI 1 ROI 2 ROI 3 POI 2 POI 3 Points of interest (POI) are extracted from the ROIs. POI 1 

Optical trap stability study for combining SR micro/nano-XRF methods with optical tweezers based sample manipulation

https://biblio.ugent.be/publication/4190508/file/4190514.pdf

Optical trap stability study for combining SR micro/nano-XRF methods with optical tweezers based sample manipulation

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