We present a numerical study of the transient acoustophoretic motion microparticles suspended in liquid-filled microchannel and driven by acoustic forces arising from an imposed standing ultrasound wave: radiation force scattering sound waves on particles Stokes drag induced streaming flow. These are calculated numerically two steps. First, thermoacoustic equations solved to first order field taking into account micrometer-thin but crucial thermoviscous boundary layer near rigid walls....

A new method is reported on how to measure the local pressure amplitude and Q factor of ultrasound resonances in microfluidic chips designed for acoustophoresis particle suspensions. The relies tracking individual polystyrene tracer microbeads straight water-filled silicon/glass microchannels. system actuated by a PZT piezo transducer attached beneath chip driven an applied ac voltage near its eigenfrequency 2 MHz. For given frequency number tracks are recorded CCD camera fitted theoretical...

We present microparticle image velocimetry measurements of suspended microparticles diameters from $0.6$ to $10\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\text{m}$ undergoing acoustophoresis in an ultrasound symmetry plane a microchannel. The motion the smallest particles is dominated by Stokes drag induced acoustic streaming flow, while largest radiation force. For all particle sizes we predict theoretically how much velocity due and streaming, respectively. These predictions include...

We present a numerical study of the acoustophoretic motion particles suspended in liquid-filled PDMS microchannel on lithium niobate substrate acoustically driven by surface acoustic waves.

We derive analytical expressions for the three-dimensional (3D) acoustophoretic motion of spherical microparticles in rectangular microchannels. The is generated by acoustic radiation force and streaming-induced drag force. In contrast to classical theory Rayleigh streaming shallow, infinite, parallel-plate channels, our does include effect microchannel side walls. resulting predictions agree well with numerics experimental measurements polystyrene spheres nominal diameters 0.537 5.33 μm. 3D...

We present a platform for micro particle image velocimetry (μPIV), capable of carrying out full-channel, temperature-controlled, long-term-stable, and automated μPIV-measurement microchannel acoustophoresis with uncertainties below 5% spatial resolution in the order 20 μm. A method to determine optimal μPIV-settings obtaining high-quality results spatially inhomogeneous acoustophoretic velocity fields large dynamical range is presented. In particular we study dependence on μPIV interrogation...

A General Defocusing Particle Tracking (GDPT) method is proposed for tracking the three-dimensional motion of particles in Lab-on-a-chip systems based on a set calibration images and normalized cross-correlation function. In comparison with other single-camera defocusing particle-tracking techniques, GDPT possesses series key advantages: it applicable to particle arbitrary shapes, intuitive easy use, can be used without advanced knowledge optics velocimetry theory, robust against outliers...

We report a temperature-controlled microfluidic acoustophoresis device capable of separating particles and transferring blood cells from undiluted whole human at volume throughput greater than 1 L h −1 . The is fabricated glass substrates polymer sheets in microscope-slide format using low-cost, rapid-prototyping techniques. This high-throughput chip (HTAC) utilizes temperature-stabilized, standing ultrasonic wave, which imposes differential acoustic radiation forces that can separate...

We present a simple and rapid method for measuring the acoustic energy density in microchannel acoustophoresis based on light-intensity measurements of suspension particles. The relies assumption that each particle undergoes single-particle acoustophoresis. It is validated by tracking method, we show proper re-scaling re-scaled light intensity plotted versus time falls universal curve. allows analysis moderate-resolution images concentration range encountered typical experiments, it an...

Acoustic manipulation of fluids and particles garners increasing interest for use in medicine biotechnology. One approach is based on actuation confined, acoustically ``leaky'' systems, but finding accurate physical models them has been stymied by a lack relevant empirical data. To advance the field, authors provide experimental benchmark results particle trajectories three dimensions, describe with minimal numerical model. They reveal that pseudo-standing wave drives acoustic streaming...

Defocus particle tracking (DPT) has gained increasing importance for its use to determine trajectories in all three dimensions with a single-camera system, as typical standard microscope, the workhorse of today's ongoing biomedical revolution. DPT methods derive depth coordinates images from different defocusing patterns that they show when observed volume much larger than respective field. Therefore it become common state-of-the-art apply image recognition techniques. Two most commonly and...

Two-photon microscopy and acoustofluidics for 3D cell study close to living conditions, precise imaging, real-time osmosis monitoring.

We present a tunable-angle wedge ultrasound transducer for improved control of microparticle acoustophoresis in microfluidic chip. The is investigated by analyzing the pattern aligned particles and induced acoustic energy density while varying geometry, coupling angle, actuation method (single-frequency or frequency-modulation actuation). energy-density analysis based on measuring transmitted light intensity through channel filled with suspension 5 µm diameter beads results are compared from...

Theoretical analysis is combined with numerical simulations to optimize designs and functionalities of acoustofluidic devices, i.e. microfluidic devices in which ultrasound waves are used anipulate biological particles. The resonance frequencies corresponding modes the acoustic fields calculated for various specific geometries glass/silicon chips containing water-filled microchannels. A special emphasis put on taking surrounding material into account, thus going beyond traditional transverse...

The increasing use of microfluidics in industrial, biomedical, and clinical applications requires a more precise control the microfluidic flows suspended particles or cells. This leads to higher demands three-dimensional automated particle tracking methods, e.g. for feedback-control systems. General defocusing (GDPT) is 3D method based on defocused images which easy standard laboratory equipment. In this work, we describe detail fast robust algorithm performing GDPT, suitable automatized...

We demonstrate the use of a two-beam optical trap (an stretcher) in low-cost microfluidic system with purpose measuring mechanical properties cells and vesicles. Delivery micrometer-sized particles to stretcher is obtained by acoustophoretic prefocusing. This focusing mechanism aims for target always flow correct height relative stretcher, induced piezo-electric ultrasound transducer attached underneath chip driven at frequency leading vertical standing wave microchannel. Trapping...

Acoustic microfluidics (or acoustofluidics) provides a non-contact and label-free means to manipulate interrogate bioparticles. Owing their biocompatibility precision, acoustofluidic approaches have enabled innovations in various areas of biomedical research. Future breakthroughs will rely on the translation these techniques from academic labs clinical industrial settings. Here, accurate characterization standardization device performance are crucial. Versatile, rapid, widely accessible...

The need for single-camera 3D particle tracking methods is growing, among others, due to the increasing focus in biomedical research often relying on single-plane microscopy imaging. Defocusing-based are ideal a wide-spread use as they rely basic imaging rather than requiring additional non-standard optics. However, has been limited by lack of accessible and easy-to-use software. DefocusTracker an open-source toolbox based universal principles General Defocusing Particle Tracking (GDPT)...