Design, modeling and characterization of microfluidic devices for ultrasonic manipulation

Neild, Adrian; Oberti, Stefano; Dual, Jürg

doi:10.1016/j.snb.2006.04.065

Cited by 90 publications

(62 citation statements)

References 21 publications

(27 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A variety of approaches to modelling resonators have been described (see for example [9,17,18]). This paper uses one-dimensional models implementing impedance transfer relationships [11,19,20].…”

Section: Introductionmentioning

confidence: 99%

Modelling for the robust design of layered resonators for ultrasonic particle manipulation

2008

View full text Add to dashboard Cite

a b s t r a c t Several approaches have been described for the manipulation of particles within an ultrasonic field. Of those based on standing waves, devices in which the critical dimension of the resonant chamber is less than a wavelength are particularly well suited to microfluidic, or ''lab on a chip" applications. These might include pre-processing or fractionation of samples prior to analysis, formation of monolayers for cell interaction studies, or the enhancement of biosensor detection capability. The small size of microfluidic resonators typically places tight tolerances on the positioning of the acoustic node, and such systems are required to have high transduction efficiencies, for reasons of power availability and temperature stability. Further, the expense of many microfabrication methods precludes an iterative experimental approach to their development. Hence, the ability to design sub-wavelength resonators that are efficient, robust and have the appropriate acoustic energy distribution is extremely important. This paper discusses one-dimensional modelling used in the design of ultrasonic resonators for particle manipulation and gives example of their uses to predict and explain resonator behaviour. Particular difficulties in designing quarter wave systems are highlighted, and modelling is used to explain observed trends and predict performance of such resonators, including their performance with different coupling layer materials.

show abstract

Section: Introductionmentioning

confidence: 99%

Modelling for the robust design of layered resonators for ultrasonic particle manipulation

2008

View full text Add to dashboard Cite

show abstract

“…However, we drop the use of this Q in favor of an electric characterization based on the impedance equation (22). The above indicators characterize the system in its entirety.…”

Section: Definition Of System Indicatorsmentioning

confidence: 99%

“…The first numerical optimization studies of acoustophoretic devices have also been performed recently, illustrating a procedure to obtain optimal acoustophoretic forces by changing the geometrical parameters of the device [21]. Other studies involve numerical characterization of the acoustic pressure wave in the microchannel and subsequent computation of particle trajectories by means of numerical integration [22][23][24][25][26][27].…”

Section: Introductionmentioning

confidence: 99%

Performance Study of Acoustophoretic Microfluidic Silicon-Glass Devices by Characterization of Material- and Geometry-Dependent Frequency Spectra

2017

View full text Add to dashboard Cite

The mechanical and electrical response of acoustophoretic microfluidic devices attached to an ac-voltage-driven piezoelectric transducer is studied by means of numerical simulations. The governing equations are formulated in a variational framework that, introducing Lagrangian and Hamiltonian densities, is used to derive the weak form for the finite-element discretization of the equations and to characterize the device response in terms of frequency-dependent figures of merit or indicators. The effectiveness of the device in focusing microparticles is quantified by two mechanical indicators: the average direction of the pressure gradient and the amount of acoustic energy localized in the microchannel. Furthermore, we derive the relations between the Lagrangian, the Hamiltonian, and three electrical indicators: the resonance Q value, the impedance, and the electric power. The frequency response of the hard-to-measure mechanical indicators is correlated to that of the easy-to-measure electrical indicators, and, by introducing optimality criteria, it is clarified to which extent the latter suffices to identify optimal driving frequencies as the geometric configuration and the material parameters vary. The latter have been varied by considering both Pyrex and aluminium nitroxide top-lid materials.

show abstract

“…In acoustophoretic simulation studies in the literature, it is not possible to see the effect of the dynamics of the piezoelectric material on the separation efficiency accurately. [31][32][33][34] This is partly because 3D models which account for PZT actuator mode shapes have not been coupled to the acoustic field inside the micro-channel. In some studies, the mode shapes of the piezoelectric actuator were not modeled, or an analytical expression which is assumed to represent the motion of the piezoelectric actuator along the length of the channel was used.…”

Section: A Acoustic System Simulationsmentioning

confidence: 99%

An integrated acoustic and dielectrophoretic particle manipulation in a microfluidic device for particle wash and separation fabricated by mechanical machining

et al. 2016

View full text Add to dashboard Cite

In this study, acoustophoresis and dielectrophoresis are utilized in an integrated manner to combine the two different operations on a single polydimethylsiloxane (PDMS) chip in sequential manner, namely, particle wash (buffer exchange) and particle separation. In the washing step, particles are washed with buffer solution with low conductivity for dielectrophoretic based separation to avoid the adverse effects of Joule heating. Acoustic waves generated by piezoelectric material are utilized for washing, which creates standing waves along the whole width of the channel. Coupled electro-mechanical acoustic 3D multi-physics analysis showed that the position and orientation of the piezoelectric actuators are critical for successful operation. A unique mold is designed for the precise alignment of the piezoelectric materials and 3D side-wall electrodes for a highly reproducible fabrication. To achieve the throughput matching of acoustophoresis and dielectrophoresis in the integration, 3D side-wall electrodes are used. The integrated device is fabricated by PDMS molding. The mold of the integrated device is fabricated using high-precision mechanical machining. With a unique mold design, the placements of the two piezoelectric materials and the 3D sidewall electrodes are accomplished during the molding process. It is shown that the proposed device can handle the wash and dielectrophoretic separation successfully. V C 2016 AIP Publishing LLC.

show abstract

Design, modeling and characterization of microfluidic devices for ultrasonic manipulation

Cited by 90 publications

References 21 publications

Modelling for the robust design of layered resonators for ultrasonic particle manipulation

Modelling for the robust design of layered resonators for ultrasonic particle manipulation

Performance Study of Acoustophoretic Microfluidic Silicon-Glass Devices by Characterization of Material- and Geometry-Dependent Frequency Spectra

An integrated acoustic and dielectrophoretic particle manipulation in a microfluidic device for particle wash and separation fabricated by mechanical machining

Contact Info

Product

Resources

About