JRM Vol.25 No.5 pp. 848-854
doi: 10.20965/jrm.2013.p0848


Evaluation of Microgap Control of Needle-Type Dispenser for Precise Microdroplet Dispensation

Shinnosuke Hirata*, Kazuki Hirose**, Yuuka Irie**,
and Hisayuki Aoyama**

*Department of Mechanical and Control Engineering, Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552, Japan

**Department of Mechanical Engineering and Intelligent Systems, Graduate School of Informatics and Engineering, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan

March 27, 2013
July 9, 2013
October 20, 2013
microdroplet dispensation, microdroplet of high-viscosity liquid, spring-mass-damper model, piezoelectric actuator, liquid-viscosity resistance
Microdroplet dispensation is required in current systems and industrial equipment. However, dispensing microdroplets from high-viscosity liquids using dropon-demand inkjet technologies is difficult. Therefore, a needle-type dispenser comprising a thin needle and glass capillary containing the liquid to be dispensed has been developed for microdroplet dispensation. When the needle passes through the capillary, a droplet of the liquid adheres to the needle tip. A microdroplet can be transcribed by bringing the needle-tip droplet into contact with the target surface. The needle-type dispenser can dispense sub-pico-liter droplets with viscosities of several hundred pascalseconds at a throughput of a droplet per 1 s. When a microdroplet is dispensed, a gap between the needle tip and target surface may be formed. Droplet volumes depend on the dispensing gap, and unstable if the gap fluctuates. Thus, a contact-detection method for the needle-tip droplet and target surface is proposed where the needle is vibrated by a piezoelectric actuator using a leaf spring. The needle-vibration characteristics depend on conditions between the needletip droplet and target surface. Contact of the needletip droplet with the target surface can be detected by the needle-vibration characteristics. The dispensing gap can thus be kept constant to dispense precise droplet volumes. In this study, the needle-vibration characteristics of the fabricated mechanism were evaluated experimentally for needle diameters of 500 and 100 µm. The needle-vibration displacements decreased depending on the dispensing gap for liquids with viscosities of 0.1 to 100 Pa•s.
Cite this article as:
S. Hirata, K. Hirose, Y. Irie, and H. Aoyama, “Evaluation of Microgap Control of Needle-Type Dispenser for Precise Microdroplet Dispensation,” J. Robot. Mechatron., Vol.25 No.5, pp. 848-854, 2013.
Data files:
  1. [1] D. Rose, “Microdispensing technologies in drug discovery,” Drug Discovery Today, Vol.4, No.9, pp. 411-419, Sep. 1999.
  2. [2] M. J. Lopez-Martinez, E. M. Campo, D. Caballero, E. Fernandez, A. Errachid, J. Esteve, and J. A. Plaza, “Versatile micropipette technology based on deep reactive ion etching and anodic bonding for biological applications,” J. Micromech. Microeng., Vol.19, No.10, pp. 105013-105022, Oct. 2009.
  3. [3] T.R. Hebner, C. C.Wu, D. Marcy,M. H. Lu, and J. C. Sturm, “Inkjet printing of doped polymers for organic light emitting devices,” Applied Physics Letters, Vol.72, No.5, pp. 519-521, Feb. 1998.
  4. [4] Y.Wang, J. Bokor, and A. Lee, “Maskless Lithography Using Drop-On-Demand Inkjet Printing Method,” Proc. SPIE, Bellingham, WA, USA, Vol.5374, pp. 628-636, Feb. 2004.
  5. [5] T. Kitahara, “Ink-jet head with multi-layer piezoelectric actuator,” Proc. of IS&T’s 11th Int. Congress on Adv. in Non-Impact Printing Technologies, Hilton Head, SC, USA, pp. 346-349, Oct. 29 to Nov. 3, 1995.
  6. [6] T. Takahashi and M. Okumura, “Novel Micro Piezo Technology for Ink jet Printhead,” Proc. of IS&T’s 23rd Int. Conf. on Digital Printing Technologies and Digital Fabrication 2007, Anchorage, AK, USA, pp. 314-318, Sep. 16-22, 2007.
  7. [7] J. M. Meacham, M. J. Varady, F. L. Degertekin, and A. G. Fedorov, “Droplet formation and ejection from a micromachined ultrasonic droplet generator: Visualization and scaling,” PHYSICS OF FLUIDS, Vol.17, No.10, pp. 100605 1-8, Oct. 2005.
  8. [8] H. Miyazaki, T. Miyoshi, T. Sato, and H. Mizoguchi, “Construction of Micro Drop Application System with Visual Feedback,” Trans. Jpn. Soc. Mech. Eng. Ser. C, Vol.63, No.609, pp. 1574-1581, May 1997 (in Japanese).
  9. [9] T. Tanikawa, Y. Hashimoto, and T. Arai, “Micro Drops for Adhesive Bonding of Micro Assemblies and Making a 3-D Structure “Micro Scarecrow”,” Proc. of the 1998 IEEE/RSJ Int. Conf. on Intelligent Robots and Systems, Victoria, B.C., Canada, pp. 777-781, Oct. 13-17, 1998,
  10. [10] H. Aoyama, T. Ekko, Y. Adachihara, O. Fuchiwaki, D. Misaki, Y. Irie, S. Dejima, Y. Kato, and T. Usuda, “Sub-pico liter dispensing mechanism with precise optical gap detector,” Proc. of ASPE2007 Annual meeting, Dallas, TX, USA, pp. 223-226, Oct. 14-19, 2007.
  11. [11] Y. Adachihara, T. Ekko, H. Aoyama, O. Fuchiwaki, Y. Irie, S. Dejima, and T. Usuda, “Development of sub-pico liter dispensing mechanism with precise automatic optical positioning system,” Proc. of 24th ISPE Int. Conf. on CAD/CAM, Robotics & Factories of the Future, Koriyama, Japan,, July 29-31, 2008.
  12. [12] S. Hirata, K. Hirose, Y. Irie, and H. Aoyama, “Improvement of the needle-type dispenser for precise micro-droplet dispensation – Gap measurement between the needle tip and the target surface based on needle vibration –,” J. of Robotics and Mechatronics, Vol.24, No.2, pp. 284-290, Apr. 2012.
  13. [13] K. Motoo, F. Arai, T. Fukuda, M. Matsubara, K. Kikuta, T. Yamaguchi, and S. Hirano, “Touch sensor for micromanipulation with pipette using lead-free (K,Na)(Nb,Ta)O3 piezoelectric ceramics,” J. Appl. Phys., Vol.98, No.9, pp. 094505 1-6, Nov. 2005.
  14. [14] D. J. Trevoy and H. Johnson, “The Water Wettability of Metal Surfaces,” J. of Physical Chemistry, Vol.62, No.7, pp. 833-837, Feb. 1958.

*This site is desgined based on HTML5 and CSS3 for modern browsers, e.g. Chrome, Firefox, Safari, Edge, Opera.

Last updated on Jul. 19, 2024