Professor Leslie Yeo
  • MNRL
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    • Professor Leslie Yeo >
      • Curriculum Vitae
  • Research
    • Acoustofluidics >
      • Particle/Colloidal Patterning
      • Fluid Transport
      • Microcentrifugation
      • Jetting
      • Nebulisation
    • Phonon-Mediated Synthesis & Manipulation of Materials
    • Sonomechanobiology
    • Electrokinetics
    • Interfacial Flows & Soft Matter
  • Translation
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Vibration Induced Particle/Colloidal Patterning​

Picture
A standing surface acoustic wave on the substrate beneath a drop will induce a similar low amplitude standing capillary wave vibration along the drop free surface at the same frequency (typically MHz order). In addition, the drop also vibrates at its natural vibration frequency (typically kHz order) due to capillary-viscous resonance. If the drop were to contain a suspension of colloidal particles, islands of these particles are observed to form at the intersection between the nodal lines associated with the former low amplitude low frequency standing wave vibration and the circular nodal ring associated with the bulk capillary-viscous vibration of the drop, as shown above.

At higher powers commensurate with the onset of bulk internal recirculation (acoustic streaming), a curious phenomenon occurs in which the drop randomly cycles between colloidal island formation in a quiescent fluid and erasure (dispersion) of these patterns when the fluid starts to move. The fluid direction (clockwise and anti-clockwise) appears to switch randomly.
Relevant Publications
  1. H Li, JR Friend, LY Yeo. Microfluidic Colloidal Island Formation and Erasure Induced by Surface Acoustic Wave Radiation. Phys Rev Lett 101, 084502 (2008).
  2. J Guo, JLW Li, Y Chen, LY Yeo, JR Friend, Y Kang. RF-Activated Standing Surface Acoustic Wave for On-Chip Particle Manipulation. IEEE Trans Microw Theory Techn 62, 1898–1904 (2014).
  3. J Behrens, S Langelier, AR Rezk, G Lindner, LY Yeo, JR Friend. Microscale Anechoic Architecture: Acoustic Diffusers for Ultra Low Power Microparticle Separation via Traveling Surface Acoustic Waves. Lab Chip 15, 43–46 (2015).
Picture
Picture
Picture
  • MNRL
  • People
    • Professor Leslie Yeo >
      • Curriculum Vitae
  • Research
    • Acoustofluidics >
      • Particle/Colloidal Patterning
      • Fluid Transport
      • Microcentrifugation
      • Jetting
      • Nebulisation
    • Phonon-Mediated Synthesis & Manipulation of Materials
    • Sonomechanobiology
    • Electrokinetics
    • Interfacial Flows & Soft Matter
  • Translation
  • Publications
  • Positions
  • Contact