Abstract
In this study, a method to separate particles, within a small sample, based on size is demonstrated using ultrasonic actuation. This is achieved in a fluid, which has been deposited on a flat surface and is contained by a channel, such that it has a rectangular wetted area. The system utilises acoustic radiation forces (ARFs) and acoustic streaming. The force field generates two types of stable collection locations, a lower one within the liquid suspension medium and an upper one at the liquid–air interface. Acoustic streaming selectively delivers smaller particles from the lower locations to the upper ones. Experimental data demonstrate the ability to separate two sets of polystyrene microparticles, with diameters of 3 and 10 μm, into different stable locations. Methods to reduce migration of larger particles to the free surface are also investigated, thereby maximising the efficiency of the separation. Extraction of one set of 99 % pure particles at the liquid–air interface from the initial particle mixture using a manual pipette is demonstrated here. In addition, computational modelling performed suggests the critical separation size can be tuned by scaling the size of the system to alter which of ARFs and acoustic streaming-induced drag forces is dominant for given particle sizes, therefore presenting an approach to tunable particle separation system based on size.
Similar content being viewed by others
References
Barnkob R, Augustsson P, Laurell T, Bruus H (2012) Acoustic radiation-and streaming-induced microparticle velocities determined by microparticle image velocimetry in an ultrasound symmetry plane. Phys Rev E 86(5):056307
Bazou D, Kearney R, Mansergh F, Bourdon C, Farrar J, Wride M (2011) Gene expression analysis of mouse embryonic stem cells following levitation in an ultrasound standing wave trap. Ultrasound Med Biol 37(2):321–330
Bernassau AL, Courtney CRP, Beeley J, Drinkwater BW, Cumming DRS (2013) Interactive manipulation of micro particles in an octagonal sonotweezer. Appl Phys Lett 102(16):4101
Collins DJ, Alan T, Helmerson K, Neild A (2013) Surface acoustic waves for on-demand production of picoliter droplets and particle encapsulation. Lab Chip 13(16):3225–3231
Frampton KD, Martin SE, Minor K (2003) The scaling of acoustic streaming for application in micro-fluidic devices. Appl Acoust 64(7):681–692
Frampton KD, Minor K, Martin S (2004) Acoustic streaming in micro-scale cylindrical channels. Appl Acoust 65(11):1121–1129
Franke T, Braunmuller S, Schmid L, Wixforth A, Weitz DA (2010) Surface acoustic wave actuated cell sorting (SAWACS). Lab Chip 10(6):789–794
Gattiker F, Umbrecht F, Neuenschwander J, Sennhauser U, Hierold C (2008) Novel ultrasound read-out for a wireless implantable passive strain sensor (WIPSS). Sens Actuators A Phys 145–146:291–298
Gau H, Herminghaus S, Lenz P, Lipowsky R (1999) Liquid morphologies on structured surfaces: from micro channels to microchips. Science 283(5398):46–49
Glynne-Jones P, Demore CEM, Congwei Y, Yongqiang Q, Cochran S, Hill M (2012) Array-controlled ultrasonic manipulation of particles in planar acoustic resonator. IEEE Trans Ultrason Ferroelectr Freq Control 59(6):1258–1266
Gor’kov L (1962) On the forces acting on a small particle in an acoustical field in an ideal fluid. Sov Phys Dokl 6:773–775
Gralinski I, Alan T, Neild A (2012) Non-contact acoustic trapping in circular cross-section glass capillaries: a numerical study. J Acoust Soc Am 132(5):2978–2987
Gupta S, Feke DL, Manas-Zloczower I (1995) Fractionation of mixed particulate solids according to compressibility using ultrasonic standing wave fields. Chem Eng Sci 50(20):3275–3284
Hagsäter S, Lenshof A, Skafte-Pedersen P, Kutter JP, Laurell T, Bruus H (2008) Acoustic resonances in straight micro channels: beyond the 1D-approximation. Lab Chip 8(7):1178–1184
Hamilton MF, Ilinskii YA, Zabolotskaya EA (2003) Acoustic streaming generated by standing waves in two-dimensional channels of arbitrary width. J Acoust Soc Am 113(1):153–160
Hammarström B, Laurell T, Nilsson J (2012) Seed particle-enabled acoustic trapping of bacteria and nanoparticles in continuous flow systems. Lab Chip 12(21):4296–4304
Hill M, Townsend RJ, Harris NR (2008) Modelling for the robust design of layered resonators for ultrasonic particle manipulation. Ultrasonics 48(6):521–528
Hultström J, Manneberg O, Dopf K, Hertz HM, Brismar H, Wiklund M (2007) Proliferation and viability of adherent cells manipulated by standing-wave ultrasound in a microfluidic chip. Ultrasound Med Biol 33(1):145–151
Johansson L, Evander M, Lilliehorn T, Almqvist M, Nilsson J, Laurell T, Johansson S (2013) Temperature and trapping characterization of an acoustic trap with miniaturized integrated transducers—towards in-trap temperature regulation. Ultrasonics 53(5):1020–1032
Johnson DA, Feke DL (1995) Methodology for fractionating suspended particles using ultrasonic standing wave and divided flow fields. Sep Technol 5(4):251–258
Landenberger B, Höfemann H, Wadle S, Rohrbach A (2012) Microfluidic sorting of arbitrary cells with dynamic optical tweezers. Lab Chip 12(17):3177–3183
Lei J, Glynne-Jones P, Hill M (2013) Acoustic streaming in the transducer plane in ultrasonic particle manipulation devices. Lab Chip 13(11):2133–2143
Leighton T (1994) The acoustic bubble. Academic Press, London
Li H, Friend JR, Yeo LY (2008) Microfluidic colloidal island formation and erasure induced by surface acoustic wave radiation. Phys Rev Lett 101(8):084502
Manneberg O, Vanherberghen B, Svennebring J, Hertz HM, Onfelt B, Wiklund M (2008) A three-dimensional ultrasonic cage for characterization of individual cells. Appl Phys Lett 93(6):063901–063903
Muller PB, Barnkob R, Jensen MJH, Bruus H (2012) A numerical study of microparticle acoustophoresis driven by acoustic radiation forces and streaming-induced drag forces. Lab Chip 12(22):4617–4627
Nam J, Lim H, Kim D, Shin S (2011) Separation of platelets from whole blood using standing surface acoustic waves in a micro channel. Lab Chip 11(19):3361–3364
Neild A, Oberti S, Beyeler F, Dual J, Nelson BJ (2006) A micro-particle positioning technique combining an ultrasonic manipulator and a micro gripper. J Micromech Microeng 16(8):1562
Neild A, Oberti S, Dual J (2007) Design, modelling and characterization of microfluidic devices for ultrasonic manipulation. Sens Actuators B Chem 121(2):452–461
Nyborg WL (1958) Acoustic streaming near a boundary. J Acoust Soc Am 30:329
Nyborg W (1965) Acoustic streaming. Phys acoust 2(Pt B):265
Oberti S, Neild A, Dual J (2007) Manipulation of micrometer sized particles within a micro machined fluidic device to form two-dimensional patterns using ultrasound. J Acoust Soc Am 121:778
Petersson F, Nilsson A, Holm C, Jönsson H, Laurell T (2005) Continuous separation of lipid particles from erythrocytes by means of laminar flow and acoustic standing wave forces. Lab Chip 5(1):20–22
Petersson F, Åberg L, Swärd-Nilsson A-M, Laurell T (2007) Free flow acoustophoresis: microfluidic-based mode of particle and cell separation. Anal Chem 79(14):5117–5123
Rife J, Bell M, Horwitz J, Kabler M, Auyeung R, Kim W (2000) Miniature valveless ultrasonic pumps and mixers. Sens Actuators A Phys 86(1):135–140
Rogers P, Neild A (2011) Selective particle trapping using an oscillating microbubble. Lab Chip 11(21):3710–3715
Rogers P, Gralinski I, Galtry C, Neild A (2013) Selective particle and cell clustering at air–liquid interfaces within ultrasonic microfluidic systems. Microfluid Nanofluid 14(3–4):469–477
Shafiee H, Sano MB, Henslee EA, Caldwell JL, Davalos RV (2010) Selective isolation of live/dead cells using contactless dielectrophoresis (cDEP). Lab Chip 10(4):438–445
Shao FF, Neild A, Ng TW (2010) Hydrophobicity effect in the self assembly of particles in an evaporating droplet. J Appl Phys 108(3):034512–034518
Shi J, Ahmed D, Mao X, Lin S-CS, Lawit A, Huang TJ (2009a) Acoustic tweezers: patterning cells and micro particles using standing surface acoustic waves (SSAW). Lab Chip 9(20):2890–2895
Shi J, Huang H, Stratton Z, Huang Y, Huang TJ (2009b) Continuous particle separation in a microfluidic channel via standing surface acoustic waves (SSAW). Lab Chip 9(23):3354–3359
Sritharan K, Strobl C, Schneider M, Wixforth A, Guttenberg Zv (2006) Acoustic mixing at low Reynold’s numbers. Appl Phys Lett 88(5):054102–054103
Tan JN, Neild A (2012) Microfluidic mixing in a Y-junction open channel. AIP Advances 2(3):032111–032160
Weiser M, Apfel R, Neppiras E (1984) Interparticle forces on red cells in a standing wave field. Acta Acustica United Acustica 56(2):114–119
Woias P (2005) Micropumps—past, progress and future prospects. Sens Actuators B Chem 105(1):28–38
Xu L, Ng TW, Neild A (2009) Delicate selective single particle handling with a float-sink scheme. Appl Phys Lett 94(3):034103–034104
Yaralioglu GG, Wygant IO, Marentis TC, Khuri-Yakub BT (2004) Ultrasonic mixing in microfluidic channels using integrated transducers. Anal Chem 76(13):3694–3698
Acknowledgments
The authors gratefully acknowledge the support of the Australian Research Council in the form of Grant No. DP110104010.
Author information
Authors and Affiliations
Corresponding author
Electronic supplementary material
Below is the link to the electronic supplementary material.
Supplementary material 1 (WMV 13484 kb)
Rights and permissions
About this article
Cite this article
Devendran, C., Gralinski, I. & Neild, A. Separation of particles using acoustic streaming and radiation forces in an open microfluidic channel. Microfluid Nanofluid 17, 879–890 (2014). https://doi.org/10.1007/s10404-014-1380-4
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10404-014-1380-4