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Microscale channel-based acoustic waveguides
Acoustofluidic devices typically generate acoustic pressure fields according to channel resonance or substrate wave nodal conditions. It turns out that channel features can essentially generate their own self-aligned acoustic fields as well, regardless of their orientation to an underlying substrate wave. These fields will enable continuous manipulation of much smaller micro and nano-particles than previously possible for a range of early diagnosis and sample preparation applications. This work appeared in Physical Review Letters (2018); and Physical Review Letters (2017). |
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Focused acoustic waves for single cell sorting and nanoparticle manipulation
Focussed acoustic waves can be used for continuous highly selective cell sorting. By altering the flow field via acoustic streaming cells can be selectively captured and nanoparticles manipulated as well. This work appeared in Lab on a Chip (2016); and Lab on a Chip (2017); and Lab on a Chip (2017); and Lab on a Chip (2017). |
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Time-of-flight-regime surface acoustic waves (SAW)
Nanosecond-pulsed counter-propagating SAW permits the arbitrary spatial localization of a standing wave along the propagation axis. This work appeard in Science Advances (2016). |
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Focussed acoustic streaming for size-selective micro and nanopartcle manipulation
HIghly focussed transducers permit the combination of acoustic streaming and an acoustic radiation force field for size-dependent microfluidic manipulation. This work is published in Analytical Chemistry (2016) |
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Two-dimensional patterning of individual cells
Reducing the acoustic wavelength to that on the order of the dimensions of cells permits the spatial separation and on-demand patterning of individual cells. This work appeared in Nature Communications (2015). |
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Deterministic particle separation
In this work, we developed a system for the deterministic separation of particles using either electric or acoustic forces generated on the same platform; the relevant force for separation is a function of the channel height, with the dielectrophoretic force dominant for lower channels and the acoustic force in channels with higher ceilings. In the video, larger 6.6 µm particles are perfectly separated from smaller 5.0 µm particles. For more information, see our work in Lab on a Chip (2014). |
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Controlled particle concentration and release
In this work, we developed an efficient system for the on-demand concentration and release of particles and cells, where the vertical component of the acoustic beam is used. Low power, efficient techniques such as this will be directly applicable to point of care diagnostic systems. For more information, see our publication in Applied Physics Letters (2014). |
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Microfluidic droplet production and particle encapsulation
In this work, we developed a system using surface acoustic waves (SAW) for the on-demand production of picoliter-scale droplets with combined particle encapsulation. In the videos, water droplets are produced in a continuous oil flow on-demand. This work appeared in Lab on a Chip (2013). |
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Surface acoustic wave atomization
Piezoelectric methods including those utilizing surface acoustic waves (SAW) are the subject of increasing research due to their ability to generate relatively mono-disperse droplet size distributions during atomization (the process of converting a bulk liquid into an aerosol spray). However, the parameters that determine what these sizes are remain relatively unexplored for SAW atomization. In this work, I developed an theoretical model to estimate droplet sizes based on the Navier-Stokes equations. Special thanks to our collaborators Andreas Winkler and Hagen Schmidt at IFW Dresden. The video to the left is presented at 2000 fps. This work appeared in Physical Review E (2012). |
