| 1. |
- Farahi, R. H., et al.
(författare)
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Microscale Marangoni actuation : All-optical and all-electrical methods
- 2006
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Ingår i: Ultramicroscopy. - : Elsevier BV. - 0304-3991 .- 1879-2723. ; 106:8-9, s. 815-821
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Tidskriftsartikel (refereegranskat)abstract
- We present experimental results from an all-optical microfluidic platform that may be complimented by a thin film all-electrical network. Using these configurations we have studied the microfluidic convective flow systems of silicone oil, glycerol, and 1,3,5-trinitrotoluene on open surfaces through the production of surface tension gradients derived from thermal gradients. We show that sufficient localized thermal variation can be created utilizing surface plasmons and/or engaging individually addressable resistive thermal elements. Both studies manipulate fluids via Marangoni forces, each having their unique exploitable advantages. Surface plasmon excitation in metal foils are the driving engine of many physical-, chemical-, and bio-sensing applications. Incorporating, for the first time, the plasmon concept in microfluidics, our results thus demonstrate great potential for simultaneous fluid actuation and sensing. (c) 2006 Elsevier B.V. All rights reserved.
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| 2. |
- Lereu, A. L., et al.
(författare)
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Plasmonic Marangoni forces
- 2006
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Ingår i: Journal of the European Optical Society-Rapid Publications. - : European Optical Society. - 1990-2573. ; 1, s. 06030-
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Tidskriftsartikel (refereegranskat)abstract
- Localized surface-tension-driven forces (microscale Marangoni effect) caused by a temperature inhomogeneity from the decay of optically excited surface plasmons into phonons have been engaged in the actuation of adsorbed and applied liquid on a thin metal film. Microfluidic operations of transport, separation, mixing, and sorting have been experimentally and theoretically demonstrated using this all-optical modulation scheme.
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| 3. |
- Passian, A., et al.
(författare)
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Nonradiative surface plasmon assisted microscale Marangoni forces
- 2006
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Ingår i: Physical Review E. Statistical, Nonlinear, and Soft Matter Physics. - 1539-3755 .- 1550-2376. ; 73:6, s. 066311-
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Tidskriftsartikel (refereegranskat)abstract
- When a liquid droplet experiences a temperature inhomogeneity along its bounding surface, a surface energy gradient is engendered, which when, in a continuous sense, exceeding a threshold, results in a convective flow dissipating the energy. If the associated temperature gradients are sustained by the interface between the liquid and a supporting substrate, the induced flow can result in the lateral motion of the droplet overcoming the viscosity and inertia. Recently, pico-liter adsorbed and applied droplets were shown experimentally to be transported, and divided by the decay of optically excited surface plasmons into phonons in a thin gold foil. The decaying events locally modify the temperature of the liquid-solid interface, establishing microscale thermal gradients of sufficient magnitude for the droplet to undergo thermocapillary flow. We present experimental evidence of such gradients resulting in local surface modification associated with the excitation of surface plasmons. We show theoretically that the observed effect is due to Marangoni forces, and computationally visualize the flow characteristics for the experimental parameters. As an application based on our results, we propose a method for an all-optical modulation of light by light mediated by the droplet oscillations. Furthermore, the results have important consequences for microfluidics, droplet actuation, and simultaneous surface plasmon resonance sensing and spectroscopy.
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