Acousto-plasmofluidics: Acoustic modulation of surface plasmon resonance in microfluidic systems

Abstract

We acoustically modulated the localized surface plasmon resonances (LSPRs) of metal nanostructures integrated within microfluidic systems. An acoustically driven micromixing device based on bubble microstreaming quickly and homogeneously mixes multiple laminar flows of different refractive indices. The altered refractive index of the mixed fluids enables rapid modulation of the LSPRs of gold nanodisk arrays embedded within the microfluidic channel. The device features fast response for dynamic operation, and the refractive index within the channel is tailorable. With these unique features, our “acousto-plasmofluidic” device can be useful in applications such as optical switches, modulators, filters, biosensors, and lab-on-a-chip systems.

Acoustofluidic Rotational Manipulation of Cells and Organisms Using Oscillating Solid Structures

“…Here, we present an acoustofluidic device that achieves highly tunable on‐chip rotational manipulation of single HeLa cells and model organism Caenorhabditis elegans ( C. elegans ) using acoustic waves. In particular, we employ steady streaming microvortices generated by oscillating solid structures in an acoustic field where the cells or the organisms are being rotated by the torque generated via the streaming flows.…”

Microfluidic hydrodynamic focusing for synthesis of nanomaterials

“…Given the latter, the average mixing time τ mix can be calculated using the following equation: $${\tau }_{\mathrm{italicmix}}\propto x^2/D$$ where x is the diffusion length (the distance that the solute needs to travel during the diffusion), and D is the diffusion coefficient. In low Re microfluidic systems, various mixing mechanisms have been demonstrated [17] using active approaches, such as magnetic [18,19], electrokinetic [20], acoustic [21–23], optical based [24] as well as passive approaches such as tesla microstructures [25,26], serpentine channels [27], and lamination [28]. These approaches either require an external mechanism to induce mixing or lacks the dynamic control of the fluid interface.…”

Ultrasonic Influence on Plasmonic Effects Exhibited by Photoactive Bimetallic Au-Pt Nanoparticles Suspended in Ethanol

“…Specifically, in this work, an attempt has been made for further investigate the transmittance of NLO signals may receive an opposite influence from multiphotonic absorption and the optical Kerr effect when the propagation of US takes place in a nonlinear sample. Some examples that illustrate the importance of modulating optical signals by ultrasonic frequencies are related to quantum plasmonic sensors assisted by NLO effects [41] and microfluids with properties governed by the incorporation of plasmonic nanostructures and acoustic signals [42]. In this direction, the main purpose of this work is to evaluate the influence of ultrasonic signals in the plasmonic response exhibited by nanocolloidal solutions.…”