Microfluidics and Nanofluidics

, Volume 19, Issue 4, pp 837–844 | Cite as

All-silica microfluidic optical stretcher with acoustophoretic prefocusing

  • Giovanni NavaEmail author
  • Francesca Bragheri
  • Tie Yang
  • Paolo Minzioni
  • Roberto Osellame
  • Ilaria Cristiani
  • Kirstine Berg-Sørensen
Research Paper


Acoustophoresis is a widely reported and used technique for microparticle manipulation and separation. In the study described here, acustophoresis is employed to prefocus the flow (i.e., focusing occurring upstream of the analysis region) in a microfluidic chip intended for optical trapping and stretching. The whole microchip is made of silica with optical waveguides integrated by femtosecond laser writing. The acoustic force is produced by driving an external piezoelectric ceramic attached underneath the microchip at the chip resonance frequency. Thanks to an efficient excitation of acoustic waves in both water and glass, acoustophoretic focusing is observed along the channel length (>40 mm) and it is successfully demonstrated both with polystyrene beads, swollen red blood cell, and cells from mouse fibroblast cellular lines (L929). Moreover, by comparing results of cell stretching measurements, we demonstrate that acoustic waves do not alter the optical deformability of the cells and that the acoustic prefocusing results in a considerable enhancement of throughput in optical stretching experiments.


Optical stretcher Acoustic prefocusing Femtosecond laser micromachining 



We acknowledge financial support from COST action MP1205 for two short-term scientific missions of GN to DTU as well as Fondazione Cariplo through the Grant “Optofluidic chips for the study of cancer cell mechanical properties and invasive capacities” (Ref. # 2011-0370). In addition, we acknowledge enlightening discussions with Peter Barkholt Müller and Henrik Bruus, and we thank Livia Visai and Nora Bloise for the L929 cells growth, preparation, and suspension.

Supplementary material

Supplementary material 1 (AVI 1940 kb)

Supplementary material 2 (AVI 1054 kb)


  1. Adams JD, Ebbesen CL, Barnkob R, Yang AHJ, Soh HT, Bruus H (2012) High-throughput, temperature-controlled microchannel acoustophoresis device made with rapid prototyping. J Micromech Microeng 22(7):075017. doi: 10.1088/0960-1317/22/7/075017 CrossRefGoogle Scholar
  2. Bellini N, Vishnubhatla KC, Bragheri F, Ferrara L, Minzioni P, Ramponi R, Cristiani I, Osellame R (2010) Femtosecond laser fabricated monolithic chip for optical trapping and stretching of single cells. Opt Express 18(5):4679–4688CrossRefGoogle Scholar
  3. Bellini N, Bragheri F, Cristiani I, Guck J, Osellame R, Whyte G (2012) Validation and perspectives of a femtosecond laser fabricated monolithic optical stretcher. Biomed Opt Express 3(10):2658–2668CrossRefGoogle Scholar
  4. Bruus H (2008) Theoretical microfluidics. Oxford University Press, Oxford, p 364. Retrieved from
  5. Bruus H (2012) Acoustofluidics 2: perturbation theory and ultrasound resonance modes. Lab Chip 12(1):20–28. doi: 10.1039/c1lc20770a CrossRefGoogle Scholar
  6. Büyükkoçak S, Özer MB, Çetin B (2014) Numerical modeling of ultrasonic particle manipulation for microfluidic applications. Microfluid Nanofluid 17(6):1025–1037. doi: 10.1007/s10404-014-1398-7 CrossRefGoogle Scholar
  7. Chung AJ, Gossett DR, Di Carlo D (2012) Three dimensional, sheathless, and high-throughput microparticle inertial focusing through geometry-induced secondary flows. Small. doi: 10.1002/smll.201202413 Google Scholar
  8. De Souza N (2011) Single-cell methods. Nat Methods 9(1):35-35. doi: 10.1038/nmeth.1819 Google Scholar
  9. Devendran C, Gralinski I, Neild A (2014) Separation of particles using acoustic streaming and radiation forces in an open microfluidic channel. Microfluid Nanofluid 17(5):879–890. doi: 10.1007/s10404-014-1380-4 CrossRefGoogle Scholar
  10. Dochow S, Krafft C, Neugebauer U, Bocklitz T, Henkel T, Mayer G, Popp J (2011) Tumour cell identification by means of Raman spectroscopy in combination with optical traps and microfluidic environments. Lab Chip 11(8):1484–1490. doi: 10.1039/c0lc00612b CrossRefGoogle Scholar
  11. Faigle C, Lautenschläger F, Whyte G, Homewood P, Martín-Badosa E, Guck J (2015) A monolithic glass chip for active single-cell sorting based on mechanical phenotyping. Lab Chip 15(5):1267–1275. doi: 10.1039/c4lc01196a CrossRefGoogle Scholar
  12. Gossett DR, Tse HTK, Lee SA, Ying Y, Lindgren AG, Yang OO, Rao J, Clark AT, Di Carlo D (2012) Hydrodynamic stretching of single cells for large population mechanical phenotyping. Proc Natl Acad Sci 109(20):7631–7635. doi: 10.1073/pnas.1200107109 CrossRefGoogle Scholar
  13. Guck J, Ananthakrishnan R, Mahmood H, Moon TJ, Cunningham CC, Käs J (2001) The optical stretcher: a novel laser tool to micromanipulate cells. Biophys J 81(2):767–784CrossRefGoogle Scholar
  14. Guck J, Schinkinger S, Lincoln B, Wottawah F, Ebert S, Romeyke M, Bilby C (2005) Optical deformability as an inherent cell marker for testing malignant transformation and metastatic competence. Biophys J 88(5):3689–3698CrossRefGoogle Scholar
  15. Khoury M, Barnkob R, Laub Busk L, Tidemand-Lichtenberg P, Bruus H, Berg-Sørensen K (2012) Optical stretching on chip with acoustophoretic prefocusing. In: Dholakia K, Spalding GC (eds) SPIE nanoscience + engineering. International Society for Optics and Photonics, p 84581E. doi: 10.1117/12.945923
  16. Knight J, Vishwanath A, Brody J, Austin R (1998) Hydrodynamic focusing on a silicon chip: mixing nanoliters in microseconds. Phys Rev Lett 80(17):3863–3866. doi: 10.1103/PhysRevLett.80.3863 CrossRefGoogle Scholar
  17. Kotari H, Motosuke M (2014) Simple applications of microparticle transportation by tender optical scattering force. Microfluid Nanofluid. doi: 10.1007/s10404-014-1459-y Google Scholar
  18. Kunstmann-Olsen C, Hoyland JD, Rubahn H-G (2011) Influence of geometry on hydrodynamic focusing and long-range fluid behavior in PDMS microfluidic chips. Microfluid Nanofluid 12(5):795–803. doi: 10.1007/s10404-011-0923-1 CrossRefGoogle Scholar
  19. Lai C-W, Hsiung S-K, Yeh C-L, Chiou A, Lee G-B (2008) A cell delivery and pre-positioning system utilizing microfluidic devices for dual-beam optical trap-and-stretch. Sens Actuators B Chem 135(1):388–397. doi: 10.1016/j.snb.2008.08.041 CrossRefGoogle Scholar
  20. Lautenschläger F, Paschke S, Schinkinger S, Bruel A, Beil M, Guck J (2009) The regulatory role of cell mechanics for migration of differentiating myeloid cells. Proc Natl Acad Sci 106(37):15696–15701. doi: 10.1073/pnas.0811261106 CrossRefGoogle Scholar
  21. Lee G-B, Chang C-C, Huang S-B, Yang R-J (2006) The hydrodynamic focusing effect inside rectangular microchannels. J Micromech Microeng 16(5):1024–1032. doi: 10.1088/0960-1317/16/5/020 CrossRefGoogle Scholar
  22. Lincoln B, Schinkinger S, Travis K, Wottawah F, Ebert S, Sauer F, Guck J (2007) Reconfigurable microfluidic integration of a dual-beam laser trap with biomedical applications. Biomed Microdevices 9(5):703–710. doi: 10.1007/s10544-007-9079-x CrossRefGoogle Scholar
  23. Maloney JM, Nikova D, Lautenschläger F, Clarke E, Langer R, Guck J, Van Vliet KJ (2010) Mesenchymal stem cell mechanics from the attached to the suspended state. Biophys J 99(8):2479–2487. doi: 10.1016/j.bpj.2010.08.052 CrossRefGoogle Scholar
  24. Otto O, Rosendahl P, Mietke A, Golfier S, Herold C, Klaue D, Girardo S, Pagliara S, Ekpenyong A, Jacobi A, Wobus M, öpfner N, Keyser UF, Mansfeld J, Fischer-Friedrich E, Guck J (2015) Real-time deformability cytometry: on-the-fly cell mechanical phenotyping. Nat Methods 12(3):199–202. doi: 10.1038/NMETH.3281
  25. Paie P, Bragheri F, Vazquez RM, Osellame R (2014) Straightforward 3D hydrodynamic focusing in femtosecond laser fabricated microfluidic channels. Lab Chip 14(11):1826–1833. doi: 10.1039/C4LC00133H CrossRefGoogle Scholar
  26. Remmerbach TW, Wottawah F, Dietrich J, Lincoln B, Wittekind C, Guck J (2009) Oral cancer diagnosis by mechanical phenotyping. Cancer Res 69(5):1728–1732. doi: 10.1158/0008-5472.can-08-4073 CrossRefGoogle Scholar
  27. Sajeesh P, Sen AK (2013) Particle separation and sorting in microfluidic devices: a review. Microfluid Nanofluid 17(1):1–52. doi: 10.1007/s10404-013-1291-9 CrossRefGoogle Scholar
  28. Yang T, Paiè P, Nava G, Bragheri F, Vazquez RM, Minzioni P, Cristiani I (2015) An integrated optofluidic device for single-cell sorting driven by mechanical properties. Lab Chip 15(5):1262–1266. doi: 10.1039/C4LC01496K CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  • Giovanni Nava
    • 1
    • 2
    Email author
  • Francesca Bragheri
    • 3
  • Tie Yang
    • 1
  • Paolo Minzioni
    • 1
  • Roberto Osellame
    • 3
  • Ilaria Cristiani
    • 1
  • Kirstine Berg-Sørensen
    • 4
  1. 1.Integrated Photonics Lab, Department of Electrical, Computer, and Biomedical EngineeringUniversità di PaviaPaviaItaly
  2. 2.Dipartimento di Biotecnologie Mediche e Medicina TraslazionaleUniversità di MilanoSegrateItaly
  3. 3.Istituto di Fotonica e NanotecnologieCNR & Dipartimento di Fisica Politecnico di MilanoMilanItaly
  4. 4.Department of PhysicsTechnical University of DenmarkKgs. LyngbyDenmark

Personalised recommendations