Abstract
We present a diagnostic platform for measuring three-dimensional three-component (3D3C) velocity fields in microscopic volumes. The imaging system uses high-speed Nipkow spinning disk confocal microscopy. Confocal microscopy provides optical sectioning using pinhole spatial filtering which rejects light originating from out-of-focus objects. The system accomplishes volumetric scanning by rapid translation of the high numerical aperture objective using a piezo objective positioner. The motion of fluorescent microspheres is quantified using 3D3C super resolution particle-imaging velocimetry with instantaneous spatial resolutions of the order of 5m or less in all three dimensions. We examine 3D3C flow in a PDMS microchannel with an expanding section at 3D acquisition rates of 30Hz, and find strong agreement with a computational model. Equations from the PIV and PTV literature adapted for a scanning objective provide estimates of maximum measurable velocity. The technique allows for isosurface visualization of 3D particle motion and robust high spatial resolution velocity measurements without requiring a calibration step or reconstruction algorithms.
Original language | English (US) |
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Article number | 085304 |
Journal | Measurement Science and Technology |
Volume | 23 |
Issue number | 8 |
DOIs | |
State | Published - Aug 2012 |
Keywords
- PIV
- PTV
- confocal
- micro PIV
- microfluidics
- microscopy
- objective positioner
- particle-image velocimetry
- particle-tracking velocimetry
- piezo
- piezo actuated
- super resolution PIV
- temporally resolved
- time resolved
- volumetric scanning
ASJC Scopus subject areas
- Instrumentation
- Engineering (miscellaneous)
- Applied Mathematics