Journal of Micro-Nano Mechatronics

, Volume 7, Issue 1–3, pp 87–95 | Cite as

Stable ejection of micro droplets containing microbeads by a piezoelectric inkjet head

Research Paper


The droplet ejection technology commonly used in inkjet printers has become the focus of numerous biofabrication research field including recent research that examined the ejection of cells through the jets. However, no studies have addressed clogging causes, or the trajectory errors that occur when ejecting particles several tens of micrometers in diameter. Nor have any studies investigated the specific conditions that permit stable ejection of liquid suspensions containing particles that are over 10 μm in diameter. In this study, one of our objectives was to experimentally establish the optimal conditions that gave stable ejection of suspensions containing particles at least 10 μm in size without trajectory errors. An inkjet head was fabricated from transparent glass to permit its interior to be observed. The behaviors of microparticles in the head were recorded using a high-speed camera, and a survey of the optimal conditions was conducted to determine conditions necessary for reliable ejection of particles over 10 μm in diameter. Furthermore, we also investigated the optimal dimensions of the print head nozzle required for stable ejection, the optimal waveform of the voltage pulse applied to a piezoelectric actuator mounted in the head, and the relation between the particle concentration and stable ejection. For stable particle ejection, the nozzle diameter must be at least three times the particle diameter and the voltage waveform driving the piezoelectric actuator generates droplets using the push-pull method. The upper limit of particle volume concentration that permits stable ejection depends on the nozzle diameter, the particle diameter, and the ejection waveform.


Droplet Inkjet printing Micro bead Particle Ejection Piezoelectric actuator 



The present work was supported in part by Grants-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology in Japan Nos. 21676002, 21111503, 21225007 and 23111705, the MEXT project, “Creating Hybrid Organs of the future” at Osaka University, Microjet Corporation, and the Industrial Technology Research Grant Program from the New Energy and Industrial Technology Development Organization (NEDO) of Japan.


  1. 1.
    United States Patent No. 5,726,724.Google Scholar
  2. 2.
    Kozawa Y (2008) Technology and the prospects for mass production of the orientation film application by the ink-jet. Display 14(6):55–58Google Scholar
  3. 3.
    Abe S, Saito H, Ueda M, Terada N, Matsuba Y (2009) “Inkjet Printing of Silver NanoPaste for Printed Electronics,” International Conference on Electronics Packaging, Proceedings, pp.302-305.Google Scholar
  4. 4.
    Reis N, Ainsley C, Derby B (2005) Ink-jet delivery of particle suspensions by piezoelectric droplet ejectors. J Appl Phys 97(9):94903CrossRefGoogle Scholar
  5. 5.
    United States Patent No. 7,803,420 B2.Google Scholar
  6. 6.
    Nishiyama Y, Nakamura M, Henmi C, Yamaguchi K, Motizuki S, Nakagawa H, Takiura K (2009) Development of three-dimensional bio-printer: construction of cell supporting structure using hydrogel and state-of-the-art inkjet technology. J Biomech Eng 131(3):035001–1CrossRefGoogle Scholar
  7. 7.
    Roda A, Guardigli M, Russo C, Pasini P, Baraldini M (2000) Protein microdeposition using a conventional ink-jet printer. Bio Techniques 28:492–496Google Scholar
  8. 8.
    Watanabe K, Miyazaki T, Matsuda R (2003) Growth Factor Array Fabrication Using a Color Ink Jet Printer. Zoological Science 20:429–434CrossRefGoogle Scholar
  9. 9.
    Rota EA, Xu T, Das M, Gregory C, Hickman JJ, Boland T (2004) Inkjet printing for high-throughput cell patterning. Biomaterials 25:3707–375CrossRefGoogle Scholar
  10. 10.
    Xu T, Jin J, Gregory C, Hickman JJ, Boland T (2005) Inkjet printing of viable mammalian cells. Biomaterials 26:93–99CrossRefGoogle Scholar
  11. 11.
    Boland T, Xu T, Damon B, Cui X (2006) Application of inkjet printing to tissue engineering. Biotechnol J 1(9):910–917CrossRefGoogle Scholar
  12. 12.
    Xu T, Gregory CA, Molnar P, Cui X, Jalota S, Bhaduri SB, Boland T (2006) Viability and electrophysiology of neural cell structures generated by the inkjet printing method. Biomaterials 27(19):3580–3588Google Scholar
  13. 13.
    Saunders RE, Gough JE, Derby B (2008) Delivery of human fibroblast cells by piezoelectric drop-on-demand inkjet printing. Biomaterials 29(2):193–203CrossRefGoogle Scholar
  14. 14.
    Mizunuma T, Yamashita Y, Sakuma S, Maruyama H, Arai F (2010) Disposable Inkjet Mechanism for Microdroplet Dispensing. Journal of Robotics and Mechatronics 22(3):341–347Google Scholar
  15. 15.
    Fujimatsu T (2007) The latest inkjet technology for 2007 Technical Information Institute Co., Ltd. pp.107-145 (in Japanese)Google Scholar
  16. 16.
    Ohnishi M (2011) The influence of atmospheric air-pressure and the self-generated air flow on wide gap ink jet print. Imaging Conference Japan 2011, pp.139–142Google Scholar

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Shuichi Yamaguchi
    • 1
    • 2
    • 3
  • Akira Ueno
    • 3
  • Keisuke Morishima
    • 1
    • 2
  1. 1.Department of Mechanical EngineeringOsaka UniversitySuitaJapan
  2. 2.Department of Bio-Applications and Systems EngineeringTokyo University of Agriculture and TechnologyKoganei-shiJapan
  3. 3.Department of Inkjet Device DevelopmentMicrojet CorporationShiojiriJapan

Personalised recommendations