We propose a patterning method of micro droplets. First, electrically charge droplets were dispersed in nonpolar solvent using electro-emulsification. Particularly, we obtained uniform droplets constantly by a double nozzle configuration with a smooth jet of the continuous phase. Then, the charged droplets were assembled in nonpolar solvent by electrostatic latent image. The charge value was estimated higher than ordinary ionized particles because the electrical charge was generated by the induction charging between the liquid interface at the nozzle and the electrode. Also, the charge of the droplets does not depend on the surface properties of the materials in the dispersed phase. Moreover, the size of the droplets could be controlled by changing the flow rate of the dispersed phase. Therefore, this method is expected to expand in applicatio n like sensors and composite materials.

References :
Toru Nakakubo, Kiyoshi Matsumoto, and Isao Shimoyama, “Patterning of Micro-Droplets in Nonpolar Solvent by Electro-Emulsification and Electrophoresis,” The 26th IEEE International Conference on Micro Electro Mechanical Systems (MEMS '13), pp. 1117 - 1120 , Taipei, Taiwan, Jan. 20 - 24, 2013.[Proceedings]