The leakage of the acoustic energy from the substrate into the drop drives bulk internal fluid recirculation within the drop, known as acoustic streaming. Through symmetry breaking, it is possible to cause the liquid to swirl circumferentially, thus generating a centrifugation action. We have demonstrated that this gives rise to a strong inertial-dominant microcentrifugation effect, which can be exploited for intense micromixing or fast particle concentration/separation. Indeed, it has been shown that chemical and biochemical reaction kinetics can be enhanced significantly when subject to the intense microcentrifugal mixing flows under surface acoustic wave excitation. In addition, we show the possibility of spinning tiny discs on which microchannels and other microfluidic structures can be patterned. Unlike its macroscopic Lab-on-a-CD counterpart, the miniaturised Lab-on-a-Disc (miniLOAD) platform does not require moving parts, is inexpensive, disposable, and significantly smaller both in terms of the disc itself and the portable palmtop battery-operated circuit used to power the chip-sized device. To the best of our knowledge, the miniLOAD concept is the first microcentrifugation platform small enough to comprise a handheld device.
Representative Publications
  1. ​H Li, JR Friend, LY Yeo. Surface Acoustic Wave Concentration of Particle and Bioparticle Suspensions. Biomed Microdev 9, 647 (2007).
  2. R Shilton, MK Tan, LY Yeo, JR Friend. Particle Concentration and Mixing in Microdrops Driven by Focused Surface Acoustic Waves. J Appl Phys 104, 014910 (2008).
  3. RV Raghavan, JR Friend, LY Yeo. Particle Concentration via Acoustically-Driven Microcentrifugation: MicroPIV Flow Visualization and Numerical Modelling Studies. Microfluid Nanofluid 8, 73–84 (2010).
  4. K Kulkarni, J Friend, L Yeo, P Perlmutter. Surface Acoustic Waves as an Energy Source for Drop Scale Synthetic Chemistry. Lab Chip 9, 754-755 (2009).
  5. KP Kulkarni, SH Ramarathinam, J Friend, L Yeo, AW Purcell, P Perlmutter. Rapid Microscale In-Gel Processing and Digestion of Proteins Using Surface Acoustic Waves. Lab Chip 10, 1518–1520 (2010).
  6. PR Rogers, JR Friend, LY Yeo. Exploitation of Surface Acoustic Waves to Drive Size-Dependent Microparticle Concentration Within a Droplet. Lab Chip 10, 2979–2985 (2010).
  7. RJ Shilton, NR Glass, P Chan, LY Yeo, JR Friend. Rotational Microfluidic Motor for On-Chip Microcentrifugation. Appl Phys Lett 98, 254103 (2011).
  8. RJ Shilton, LY Yeo, J Friend. Quantification of Surface Acoustic Wave Induced Chaotic Mixing-Flows in Microfluidic Wells. Sens Actuators B: Chemical 160, 1565–1572 (2011).
  9. NR Glass, RJ Shilton, PPY Chan, JR Friend, LY Yeo. Miniaturized Lab-on-a-Disc (miniLOAD). Small 8, 1881–1888 (2012) [Article selected as journal frontispiece 12/2012 p 1880].
  10. K Kulkarni, J Friend, L Yeo, P Perlmutter. An Emerging Reactor Technology for Chemical Synthesis: Surface Acoustic Wave-Assisted Closed-Vessel Suzuki Coupling Reactions. Ultrason Sonochem 21, 1305–1309 (2014).
  11. AMG Martins, NR Glass, S Harrison, AR Rezk, NA Porter, PD Carpenter, J Du Plessis, JR Friend, LY Yeo. Towards Complete Miniaturisation of Flow Injection Analysis Systems: Microfluidic Enhancement of Chemiluminescent Detection. Anal Chem 86, 10812–10819 (2014).
  12. KM Ang, LY Yeo, YM Hung, MK Tan. Amplitude Modulation Schemes for Enhancing Acoustically-Driven Microcentrifugation and Micromixing. Biomicrofluidics 10, 054106 (2016).
  13. L Alhasan, A Qi, A Al-Abboodi, A Rezk, PPY Chan, C Iliescu, LY Yeo. Rapid Enhancement of Cellular Spheroid Assembly by Acoustically-Driven Microcentrifugation. ACS Biomater Sci Eng 2, 1013–1022 (2016) [Article coverart selected for journal front cover].
  14. MK Tan, A Siddiqi, LY Yeo. A Facile and Flexible Method for On-Demand Directional Speed Tunability in the Miniaturised Lab-on-a-Disc. Sci Rep 7, 6652 (2017).
  15. AR Rezk, S Ramesan, LY Yeo. Plug-and-Actuate On Demand: Multimodal Individual Addressability of Microarray Plates Using Modular Hybrid Acoustic Wave Technology. Lab Chip 18, 406-411 (2018) [Article coverart selected for journal back cover p 542].
  16. A Sudeepthi, AK Sen, L Yeo. Aggregation of a Dense Suspension of Particles in a Microwell Using Surface Acoustic Wave Microcentrifugation. Microfluid Nanofluid 23, 76 (2019).
  17. H Ahmed, AR Rezk, JJ Richardson, LK Macreadie, R Babarao, ELH Mayes, L Lee, LY Yeo. Acoustomicrofluidic Assembly of Oriented and Simultaneously Activated Metal–Organic Frameworks. Nature Commun 10, 2282 (2019).
  18. A Akther, S Marqus, AR Rezk, LY Yeo. Submicron Particle and Cell Concentration in a Closed Chamber Surface Acoustic Wave Microcentrifuge. Anal Chem 92, 10024−10032 (2020).
  19. A Akther, EP Walsh, P Reineck, BC Gibson, T Ohshima, H Abe, G McColl, NL Jenkins, LT Hall, DA Simpson, AR Rezk, LY Yeo. Acoustomicrofluidic Concentration and Signal Enhancement of Fluorescent Nanodiamond Sensors. Anal Chem 93, 16133–16141 (2021).
Press Releases
  1. Miniaturised Lab-on-a-Disc, Chemistry World, 21 May 2012 (Royal Society of Chemistry).