Micromachines (Jun 2013)

On-Chip Enucleation of Bovine Oocytes using Microrobot-Assisted Flow-Speed Control

  • Akihiko Ichikawa,
  • Fumihito Arai,
  • Lin Feng,
  • Masaya Hagiwara

DOI
https://doi.org/10.3390/mi4020272
Journal volume & issue
Vol. 4, no. 2
pp. 272 – 285

Abstract

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In this study, we developed a microfluidic chip with a magnetically driven microrobot for oocyte enucleation. A microfluidic system was specially designed for enucleation, and the microrobot actively controls the local flow-speed distribution in the microfluidic chip. The microrobot can adjust fluid resistances in a channel and can open or close the channel to control the flow distribution. Analytical modeling was conducted to control the fluid speed distribution using the microrobot, and the model was experimentally validated. The novelties of the developed microfluidic system are as follows: (1) the cutting speed improved significantly owing to the local fluid flow control; (2) the cutting volume of the oocyte can be adjusted so that the oocyte undergoes less damage; and (3) the nucleus can be removed properly using the combination of a microrobot and hydrodynamic forces. Using this device, we achieved a minimally invasive enucleation process. The average enucleation time was 2.5 s and the average removal volume ratio was 20%. The proposed new system has the advantages of better operation speed, greater cutting precision, and potential for repeatable enucleation.

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