Flow-assisted Single-beam Optothermal Manipulation of Microparticles

Liu, Yangyang; Poon, Andrew W.

doi:10.1364/oe.18.018483

Cited by 27 publications

(22 citation statements)

References 12 publications

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“…A careful choice of experimental conditionswith thermophoresis and liquid convection acting in opposite directions -can eventually lead to particle aggregation at locations where the two driving forces balance each other. This effect was used to realize optothermal traps for concentrating nanoparticles, such as DNA molecules [446][447][448], as well as microscopic colloids [449][450][451][452][453]. Such trapping mechanisms, however, do not allow for the selective targeting of individual particles and, thus, they are limited to manipulating large ensembles of molecules or colloids.…”

Section: Optically Induced Thermophoresismentioning

confidence: 99%

Perspective on light-induced transport of particles: from optical forces to phoretic motion

et al. 2019

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Propulsive effects of light, which often remain unnoticed in our daily-life experience, manifest themselves on spatial scales ranging from subatomic to astronomical. Light-mediated forces can indeed confine individual atoms, cooling their effective temperature very close to absolute zero, as well as contribute to cosmological phenomena such as the formation of stellar planetary systems. In this review, we focus on the transport processes that light can initiate on small spatial scales. In particular, we discuss in depth various light-induced mechanisms for the controlled transport of microscopic particles; these mechanisms rely on the direct transfer of momentum between the particles and the incident light waves, on the combination of optical forces with external forces of other nature, and on light-triggered phoretic motion. After a concise theoretical overview of the physical origins of optical forces, we describe how these forces can be harnessed to guide particles either in continuous bulk media or in the proximity of a constraining interface under various configurations of the illuminating light beams (radiative, evanescent, or plasmonics fields). Subsequently, we introduce particle transport techniques that complement optical forces with counteracting forces of non-optical nature. We finally discuss particle actuation schemes where light acts as a fine knob to trigger and/or modulate phoretic motion in spatial gradients of non-optical (e.g., electric, chemical, or temperature) fields. We conclude by outlining possible future fundamental and applied directions for research in light-induced particle transport. We believe that this comprehensive review can inspire diverse, interdisciplinary scientific communities to devise novel, unorthodox ways of assembling and manipulating materials with light.

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Section: Optically Induced Thermophoresismentioning

confidence: 99%

Perspective on light-induced transport of particles: from optical forces to phoretic motion

et al. 2019

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“…This morphology changes and redistribution of NRs are obviously due to the localized heating generated from NRs at the focal point. (2) However, there is no signal detected at the focal point and ring structure was observed, which can be explained by a repulsive optothermal flow and direct laser generated pushing flow at the focal point (Gu et al, ; Liu et al, ). This phenomenon also exists in Figure C, although it is not very obvious due to the free diffusion of NRs after trapping.…”

Section: Resultsmentioning

confidence: 99%

Spectral properties and dynamics of gold nanorods revealed by EMCCD-based spectral phasor method

Chen

Gratton

Digman

2015

Microsc. Res. Tech.

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Gold nanorods (NRs) with tunable plasmon-resonant absorption in the near-infrared region have considerable advantages over organic fluorophores as imaging agents. However, the luminescence spectral properties of NRs have not been fully explored at the single particle level in bulk due to lack of proper analytic tools. Here we present a global spectral phasor analysis method which allows investigations of NRs' spectra at single particle level with their statistic behavior and spatial information during imaging. The wide phasor distribution obtained by the spectral phasor analysis indicates spectra of NRs are different from particle to particle. NRs with different spectra can be identified graphically in corresponding spatial images with high spectral resolution. Furthermore, spectral behaviors of NRs under different imaging conditions, e.g. different excitation powers and wavelengths, were carefully examined by our laser-scanning multiphoton microscope with spectral imaging capability. Our results prove that the spectral phasor method is an easy and efficient tool in hyper-spectral imaging analysis to unravel subtle changes of the emission spectrum. Moreover, we applied this method to study the spectral dynamics of NRs during direct optical trapping and by optothermal trapping. Interestingly, spectral shifts were observed in both trapping phenomena.

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“…Even in a microfluidic channel with a typical dimension of 100–200 μm, the absorbed power at 1.5–1.6 μm in the microfluidic channel can be high enough to generate local heating (e.g. >10°C for a power of >10 mW)34, that can in turn influence the variability of optofluidic bioassays35 and also creates local fluidic flow for microparticle manipulation (based on photothermal tweezer)36. In contrast, such photothermal effect can be neglected at 1 μm.…”

Section: Discussionmentioning

confidence: 99%

Asymmetric-detection time-stretch optical microscopy (ATOM) for ultrafast high-contrast cellular imaging in flow

Wong

Lau

et al. 2014

Sci Rep

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Accelerating imaging speed in optical microscopy is often realized at the expense of image contrast, image resolution, and detection sensitivity – a common predicament for advancing high-speed and high-throughput cellular imaging. We here demonstrate a new imaging approach, called asymmetric-detection time-stretch optical microscopy (ATOM), which can deliver ultrafast label-free high-contrast flow imaging with well delineated cellular morphological resolution and in-line optical image amplification to overcome the compromised imaging sensitivity at high speed. We show that ATOM can separately reveal the enhanced phase-gradient and absorption contrast in microfluidic live-cell imaging at a flow speed as high as ~10 m/s, corresponding to an imaging throughput of ~100,000 cells/sec. ATOM could thus be the enabling platform to meet the pressing need for intercalating optical microscopy in cellular assay, e.g. imaging flow cytometry – permitting high-throughput access to the morphological information of the individual cells simultaneously with a multitude of parameters obtained in the standard assay.

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Flow-assisted Single-beam Optothermal Manipulation of Microparticles

Cited by 27 publications

References 12 publications

Perspective on light-induced transport of particles: from optical forces to phoretic motion

Perspective on light-induced transport of particles: from optical forces to phoretic motion

Spectral properties and dynamics of gold nanorods revealed by EMCCD-based spectral phasor method

Asymmetric-detection time-stretch optical microscopy (ATOM) for ultrafast high-contrast cellular imaging in flow

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