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ABSTRACT: When applying PIV to micrometer-resolution systems, the out-of-plane velocity component has shown to be much more difficult
to obtain than the two in-plane velocity components. In this work, we present a novel stereoscopic viewing configuration for
stereoscopic micro-PIV, utilizing mm-sized mirrors introduced in front of the microscope objective lens. Attractive applications,
where the advantage of the mirror viewing configuration system could be utilized, include (on-chip) miniaturization and the
potential to introduce more than two simultaneous viewing angles. Here, a first validation of our system is presented, including
stereoscopic micro-PIV measurements in a micro-fabricated test device.
Experiments in Fluids 04/2012; 45(6):1015-1021. · 1.74 Impact Factor
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ABSTRACT: Acoustic actuation can be used to perform several tasks in microfluidic systems. In this paper, we investigate an acoustic separator through micro-PIV analysis in stop-flow mode and numerical simulations, and a good agreement between the two is found. Moreover, we demonstrate that it is not sufficient only to characterize devices in flow-through mode, since in these systems much different resonant patterns can result in similarly looking band formations. Furthermore, we conclude that extended 1D approximations of the acoustic radiation force are inadvisable, and instead, a 2D model is preferred. The results presented here provide valuable insight into the nature and functionality of acoustic microdevices, and should be useful in the interpretation and understanding of the same.
Lab on a Chip 08/2008; 8(7):1178-84. · 5.67 Impact Factor
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ABSTRACT: In this study, we provide a general investigation on micro-PIV with LED illumination. A number of improvements over previous
LED-based systems are suggested, in particular, we present a novel front-lit configuration. As a demonstration of its versatility
we have used this front-lit configuration to perform micro-PIV measurements around a 50μm squared pillar in a micro-channel
with rectangular cross section, in both fluorescent mode and scattered mode. A comparison between the two modes is supplied,
showing very good agreement between the respective velocity field results.
Experiments in Fluids 01/2008; 44(2):211-219. · 1.74 Impact Factor
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ABSTRACT: We show that full-image micro-PIV analysis in combination with images of transient particle motion is a powerful tool for experimental studies of acoustic radiation forces and acoustic streaming in microfluidic chambers under piezo-actuation in the MHz range. The measured steady-state motion of both large 5 microm and small 1 microm particles can be understood in terms of the acoustic eigenmodes or standing ultra-sound waves in the given experimental microsystems. This interpretation is supported by numerical solutions of the corresponding acoustic wave equation.
Lab on a Chip 11/2007; 7(10):1336-44. · 5.67 Impact Factor
