Flow with nanoparticle clustering controlled by optical forces in quartz glass nanoslits

Abstract

In this paper, we demonstrate nanoparticle flow control using an optical force in a confined nanospace. Using nanofabrication technologies, all-quartz-glass nanoslit channels with a sudden contraction are developed. Because the nanoslit height is comparable to the nanoparticle diameter, the motion of particles is restricted in the channel height direction, resulting in almost two-dimensional particle motion. The laser irradiates at the entrance of the sudden contraction channel, leading the trapped nanoparticles to form a cluster. As a result, the translocation of nanoparticles into the contraction channel is suppressed. Because the particle translocation restarts when the laser irradiation is stopped, we can control the nanoparticle flow into the contraction channel by switching the trapping and release of particles, realizing an intermittent flow of nanoparticles. Such a particle flow control technique in a confined nanospace is expected to improve the functions of nanofluidic devices by transporting a target material selectively to a desired location in the device.Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Optical trapping in micro- and nanoconfinement systems: Role of thermo-fluid dynamics and applications

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Applications of Optically Controlled Gold Nanostructures in Biomedical Engineering

“…Tsuji et al ( 2019 ) demonstrate that using optical forces, nanoparticle flow can be controlled in all-quartz glass nanoslit channels. Yin et al ( 2020 ) have also proposed a plasmonic nanoparticle router, which consists of a series of gold nanostrips on top of a continuous gold thin film, to transport trapped nanoparticles along designated routes in a microfluidic channel with a continuous flow under the incident unfocused light.…”

Convection Dynamics Forced by Optical Trapping with a Focused Laser Beam

“…Moreover, optical trapping of nanoparticles or molecules in highly concentrated solutions induces assembly of them at the focal spot, because the multiple particles are capable of confinement in an optical trap. The phase separation, clustering, and crystallization induced by optical trapping have attracted much attention for spatiotemporal control of the assembling process, which has been reported in various systems such as nanoparticle suspensions, − organic molecules, proteins and amino acids, , and intracellular molecules and vesicles . For realizing effective and selective manipulation, it is essential to understand the optical trapping dynamics interacted with particles, focused laser beams, and the surrounding environment.…”