Manipulations of micro/nanoparticles using gigahertz acoustic streaming tweezers

Abstract

Contactless acoustic manipulation of micro/nanoscale particles has attracted considerable attention owing to its near independence of the physical and chemical properties of the targets, making it universally applicable to almost all biological systems. Thin-film bulk acoustic wave (BAW) resonators operating at gigahertz (GHz) frequencies have been demonstrated to generate localized high-speed microvortices through acoustic streaming effects. Benefitting from the strong drag forces of the high-speed vortices, BAW-enabled GHz acoustic streaming tweezers (AST) have been applied to the trapping and enrichment of particles ranging in size from micrometers to less than 100 nm. However, the behavior of particles in such 3D microvortex systems is still largely unknown. In this work, the particle behavior (trapping, enrichment, and separation) in GHz AST is studied by theoretical analyses, 3D simulations, and microparticle tracking experiments. It is found that the particle motion in the vortices is determined mainly by the balance between the acoustic streaming drag force and the acoustic radiation force. This work can provide basic design principles for AST-based lab-on-a-chip systems for a variety of applications.

A self-contained acoustofluidic platform for biomarker detection

“…Generally, the high frequency ( ω ) Lamb wave has a short acoustic attenuation length ( L β ) and a strong body force ( F b ) to the surrounding liquid since the parameters L β and F b are proportional to ω −2 and ω 4 , respectively. 45 This indicates that the acoustic wave of higher frequency can enable faster acoustic energy dissipation in a much shorter attenuation length, which then triggers stronger acoustic streaming. This phenomenon is ideal for fluid control in microchannels.…”

“…The high resonant frequency (e.g., from hundreds of megahertz to tens of gigahertz) enhances the acoustic streaming effect by increasing the acoustic energy liquid delivery efficiency due to the large body force and short attenuation length at the solid-liquid interface. 45 In a recent work, we demonstrated a new type of acoustic streaming tweezers (AST) by integrating a piezoelectric Lamb wave resonator (LWR) into a microfluidic channel. 46 Highly confined and rapid micro-vortices streaming can be generated, which enables localized particle trapping, enrichment, and mixing.…”

Enrichment of Aggregation-Induced Emission Aggregates Using Acoustic Streaming Tweezers in Microfluidics for Trace Human Serum Albumin Detection

“…Compound ANU was prepared using a modified method of Senjuti Halder . To a stirred solution of 2-aminoanthracene (19.3 mg, 0.1 mmol) in 1 mL of dry THF, 1 mL of a solution of 1-naphthyl isocyanate (14 μL, 0.1 mmol) in dry THF was added dropwise at room temperature.…”

“…In our previous work, a gigahertz (GHz) AST was demonstrated to induce quasi-static trapping of sub-100 nm nanoparticles. 18,19 With controllable and trapping of nano-objects, this system greatly inspired us to enhance the detection efficiency of the AIE probe.…”

Biomedical Applications of Microfluidic Devices: A Review

“…Particle trapping is an extraordinary method actively used in biomedical applications by creating physical tweezers depending on the acoustic field, electric field, magnetic field, optical field, or thermal field as a driving force in every particle manipulation method. Standing waves created by two identical interdigitated transducers are critical in acoustic method for creating a high-pressure point known as a tweezer that can trap different-sized particle, which could be micron- or sub-micron size particles [ 15 , 129 , 130 ]. Without standing waves, it is possible to confine silica nanoparticles, exosomes, and drugs inside a fluid chamber as rotating droplets for biomedical applications with the help of acoustic radiation force, acoustic microstreaming, and shear stresses [ 131 ].…”