Enhancement of DNA hybridization under acoustic streaming with three-piezoelectric-transducer system

Abstract

Recently, we have demonstrated that DNA hybridization using acoustic streaming induced by two piezoelectric transducers provides higher DNA hybridization efficiency than the conventional method. In this work, we refine acoustic streaming system for DNA hybridization by inserting an additional piezoelectric transducer and redesigning the locations of the transducers. The Comsol® Multiphysics was used to design and simulate the velocity field generated by the piezoelectric agitation. The simulated velocity vector followed a spiral vortex flow field with an average direction outward from the center of the transducers. These vortices caused the lower signal intensity in the middle of the microarray for the two-piezoelectric disk design. On the contrary, the problem almost disappeared in the three-piezoelectric-disk system. The optimum condition for controlling the piezoelectric was obtained from the dye experiments with different activation settings for the transducers. The best setting was to activate the side disks and middle disk alternatively with 1 second activating time and 3 second non-activating time for both sets of transducers. DNA hybridization using microarrays for the malaria parasite Plasmodium falciparum from the optimized process yielded a three-fold enhancement of the signal compared to the conventional method. Moreover, a greater number of spots passed quality control in the optimized device, which could greatly improve biological interpretation of DNA hybridization data.

Transducer-Plane Streaming Patterns in Thin-Layer Acoustofluidic Devices

“…Understanding the driving mechanisms of acoustic streaming patterns within acoustofluidic devices is important in order to precisely control it for the enhancement or suppression of acoustic streaming for applications such as particle/cell manipulation [1-8], heat transfer enhancement [9][10][11][12], noncontact surface cleaning [13][14][15][16][17], microfluidic mixing [18][19][20][21][22][23][24][25][26][27], and transport enhancement [28][29][30][31][32][33][34][35].…”

“…INTRODUCTION Acoustic streaming is steady fluid motion driven by the absorption of acoustic energy due to the interaction of acoustic waves with the fluid medium or its solid boundaries. Understanding the driving mechanisms of acoustic streaming patterns within acoustofluidic devices is important in order to precisely control it for the enhancement or suppression of acoustic streaming for applications such as particle/cell manipulation [1-8], heat transfer enhancement [9-12], noncontact surface cleaning [13][14][15][16][17], microfluidic mixing [18][19][20][21][22][23][24][25][26][27], and transport enhancement [28][29][30][31][32][33][34][35].In most bulk micro-acoustofluidic particle and cell manipulation systems of interest, the acoustic streaming fields are dominated by boundary-driven streaming [36], which is associated with acoustic dissipation in the viscous boundary layer [37]. Theoretical work on boundary-driven streaming was initiated by Rayleigh [38], and developed by a series of modifications for particular cases [39][40][41][42][43][44], which have paved the fundamental understanding of acoustic streaming flows.…”

Dynamic Magnetic Nanomixers for Improved Microarray Assays by Eliminating Diffusion Limitation

“…To overcome this diffusion barrier, many methods such as acoustic waves agitation, electrokinetic delivery, cavitation microstreaming, air‐driven bladders, drain‐and‐fill or recirculating flow, and microfluidic chaotic mixer were developed to accelerate liquid mixing and mass transfer. Although these methods allow shorter assay time and improved signal, they often suffer from complicated operation and low flexibility, and also increase structural and fabricating complexity of the microarray.…”

Magnetic nanochain enabled microarray and microfluidic bioassays

“…However, owing to the spatial confinement in these assay system, no magnetic mixing system has been used in practice. Many methods such as acoustic waves agitation, 21 electrokinetic delivery, 22 cavitation microstreaming, 17 air-driven bladders, 23 recirculating flow, 24 and micromotor 25 have attempted to address the issue. However, these approaches necessitate additional devices that are not commonly used in biological and clinical labs, and inevitably increase the complexity of bioanalysis.…”

“…A large number of techniques have attempted to solve the mixing issue in bioassay. For example, many methods such as acoustic waves agitation 21 , electrokinetic delivery 22 , cavitation microstreaming 17 , air-driven bladders 23 , drain-and-fill or recirculating flow 24 , and microfluidic chaotic mixer 25 have been developed to accelerate the biochemical reaction in miniaturized devices.…”