An improved bulk acoustic waves chip based on a PDMS bonding layer for high-efficient particle enrichment

Research Paper


In this work, we developed a feasible way to package bulk acoustic waves chip with sandwich structure by inserting a polydimethylsiloxane (PDMS) layer as the adhesive between cover glass and silicon substrate. After spin-coating and curing process, a PDMS layer was formed on one side of the cover glass and then bonded to the silicon substrate with microchannels by oxygen plasma treating. Both simulation and experiment showed that the chip was not leaking and the acoustic waves produced by the piezoelectric transducer could be propagated through the PDMS layer. Finally, a standing wave field was formed in the microchannels. Compared with traditional chip bonded by anodic bonding, simulation results showed that this packaging method did decrease the acoustic pressure in the channel, but the reduction was acceptable. After optimizing the experimental parameters, we successfully aggregated 15-μm silica spheres under a very low input power (21 dBm) at a flow velocity of 1 ml/h, and the enrichment efficiency of silica spheres was greater than 97%.


BAWs chip PDMS layer Spin-coating Oxygen plasma treating Standing wave field 



This work was supported by the National Natural Science Foundation of China (No. 81572860) and the National Key R&D Program of China (No. 2017YFF0108600).


  1. Antfolk M, Antfolk C, Lilja H, Laurell T, Augustsson P (2015a) A single inlet two-stage acoustophoresis chip enabling tumor cell enrichment from white blood cells. Lab Chip 15:2102–2109. CrossRefGoogle Scholar
  2. Antfolk M, Magnusson C, Augustsson P, Lilja H, Laurell T (2015b) Acoustofluidic, label-free separation and simultaneous concentration of rare tumor cells from white blood cells. Anal Chem 87:9322–9328. CrossRefGoogle Scholar
  3. Augustsson P, Persson J, Ekstrom S, Ohlin M, Laurell T (2009) Decomplexing biofluids using microchip based acoustophoresis. Lab Chip 9:810–818CrossRefGoogle Scholar
  4. Bruus H (2012) Acoustofluidics 7: the acoustic radiation force on small particles. Lab Chip 12:1014–1021. CrossRefGoogle Scholar
  5. Ding XY et al (2012) On-chip manipulation of single microparticles, cells, and organisms using surface acoustic waves. Proc Natl Acad Sci USA 109:11105–11109CrossRefGoogle Scholar
  6. Dittrich PS, Tachikawa K, Manz A (2006) Micro total analysis systems. Latest advancements and trends. Anal Chem 78:3887–3907CrossRefGoogle Scholar
  7. Grenvall C, Augustsson P, Folkenberg JR, Laurell T (2009) Harmonic microchip acoustophoresis: a route to online raw milk sample precondition in protein and lipid content quality control. Anal Chem 81:6195–6200CrossRefGoogle Scholar
  8. Grenvall C, Magnusson C, Lilja H, Laurell T (2015) Concurrent isolation of lymphocytes and granulocytes using prefocused free flow acoustophoresis. Anal Chem 87:5596–5604. CrossRefGoogle Scholar
  9. Guo F et al (2016) Three-dimensional manipulation of single cells using surface acoustic waves. Proc Natl Acad Sci USA 113:1522CrossRefGoogle Scholar
  10. Hawkes JJ, Coakley WT, Gröschl M, Benes E, Armstrong S, Tasker PJ, Nowotny H (2002) Single half-wavelength ultrasonic particle filter: predictions of the transfer matrix multilayer resonator model and experimental filtration results. J Acoust Soc Am 111:1259–1266. CrossRefGoogle Scholar
  11. Hoi SK, Udalagama C, Sow CH, Watt F, Bettiol AA (2009) Microfluidic sorting system based on optical force switching. Appl Phys B-Lasers O 97:859–865CrossRefGoogle Scholar
  12. Inglis DW, Riehn R, Austin RH, Sturm JC (2004) Continuous microfluidic immunomagnetic cell separation. Appl Phys Lett 85:5093–5095CrossRefGoogle Scholar
  13. Jakobsson O, Oh SS, Antfolk M, Eisenstein M, Laurell T, Soh HT (2015) Thousand-fold volumetric concentration of live cells with a recirculating acoustofluidic device. Anal Chem 87:8497–8502. CrossRefGoogle Scholar
  14. Lenshof A, Evander M, Laurell T, Nilsson J (2012a) Acoustofluidics 5: building microfluidic acoustic resonators. Lab Chip 12:684–695. CrossRefGoogle Scholar
  15. Lenshof A, Magnusson C, Laurell T (2012b) Acoustofluidics 8: applications of acoustophoresis in continuous flow microsystems. Lab Chip 12:1210–1223. CrossRefGoogle Scholar
  16. Li YL, Dalton C, Crabtree HJ, Nilsson G, Kaler KVIS (2007) Continuous dielectrophoretic cell separation microfluidic device. Lab Chip 7:239–248CrossRefGoogle Scholar
  17. Li P et al (2015) Acoustic separation of circulating tumor cells. Proc Natl Acad Sci USA 112:4970–4975. CrossRefGoogle Scholar
  18. Ma Z, Collins DJ, Ai Y (2016) Detachable acoustofluidic system for particle separation via a traveling surface acoustic wave. Anal Chem 88:5316–5323. CrossRefGoogle Scholar
  19. Nilsson A, Petersson F, Jonsson H, Laurell T (2004) Acoustic control of suspended particles in micro fluidic chips. Lab Chip 4:131–135. CrossRefGoogle Scholar
  20. Petersson F, Nilsson A, Holm C, Jonsson H, Laurell T (2004) Separation of lipids from blood utilizing ultrasonic standing waves in microfluidic channels. The Analyst 129:938–943. CrossRefGoogle Scholar
  21. Petersson F, Aberg L, Sward-Nilsson AM, Laurell T (2007) Free flow acoustophoresis: microfluidic-based mode of particle and cell separation. Anal Chem 79:5117–5123CrossRefGoogle Scholar
  22. Rambach RW, Skowronek V, Franke T (2014) Localization and shaping of surface acoustic waves using PDMS posts: application for particle filtering and washing. RSC Adv 4:60534–60542. CrossRefGoogle Scholar
  23. Ren L et al (2015) A high-throughput acoustic cell sorter. Lab Chip 15:3870–3879. CrossRefGoogle Scholar
  24. Schmid L, Wixforth A, Weitz DA, Franke T (2011) Novel surface acoustic wave (SAW)-driven closed PDMS flow chamber. Microfluid Nanofluid 12:229–235. CrossRefGoogle Scholar
  25. Shi J, Ahmed D, Mao X, Lin SC, Lawit A, Huang TJ (2009a) Acoustic tweezers: patterning cells and microparticles using standing surface acoustic waves (SSAW). Lab Chip 9:2890–2895. CrossRefGoogle Scholar
  26. 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 9:3354–3359. CrossRefGoogle Scholar
  27. Shields CWT, Cruz DF, Ohiri KA, Yellen BB, Lopez GP (2016) Fabrication and operation of acoustofluidic devices supporting bulk acoustic standing waves for sheathless focusing of particles. Journal of Visualized Experiments JoVE. Google Scholar
  28. Urbansky A, Lenshof A, Dykes J, Laurell T, Scheding S (2016) Affinity-bead-mediated enrichment of CD8 + lymphocytes from peripheral blood progenitor cell products using acoustophoresis. Micromachines 7:101. CrossRefGoogle Scholar
  29. Wang MM et al (2005) Microfluidic sorting of mammalian cells by optical force switching. Nat Biotechnol 23:83–87CrossRefGoogle Scholar
  30. Yang AH, Soh HT (2012) Acoustophoretic sorting of viable mammalian cells in a microfluidic device. Anal Chem 84:10756–10762. CrossRefGoogle Scholar
  31. Yu XL et al (2013) Magneto-controllable capture and release of cancer cells by using a micropillar device decorated with graphite oxide-coated magnetic nanoparticles. Small 9:3895–3901CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  • Xi Shu
    • 1
  • Huiqin Liu
    • 1
  • Yezi Zhu
    • 1
  • Bo Cai
    • 1
  • Yanxia Jin
    • 2
  • Yongchang Wei
    • 2
  • Fuling Zhou
    • 2
  • Wei Liu
    • 1
  • Shishang Guo
    • 1
  1. 1.Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, School of Physics and TechnologyWuhan UniversityWuhanChina
  2. 2.Department of HematologyZhongnan Hospital of Wuhan UniversityWuhanChina

Personalised recommendations