External-voltage-free dielectrophoresis of liquid crystal droplets

Sheng Kuang Wu, Ting Shan Mo, Jia De Lin, Shuan Yu Huang, Hui Chen Yeh, Lin Jer Chen, Chia Rong Lee

Research output: Contribution to journalArticlepeer-review


This work reports, for the first time, a dielectrophoresis (DEP) effect-induced motion of liquid crystal (LC) droplets in an LC/monomer mixture sample with a poly-(N-vinyl carbazole) PVK-coated substrate without an external voltage. With the UV pre-irradiation of the PVK layer through a binary mask, a laterally non-uniform electric field can be induced between the pre-illuminated regions and the neighboring non-pre-illuminated PVK regions near the borders of the two regions. The phase separation occurs once the temperature is lower than 50C and the LC droplets can form in the sample. The pre-formed non-uniform field provides a DEP-like force to manipulate the small LC microdroplets in the pre-illuminated regions to effectively migrate to the adjacent non-pre-illuminated regions. The continuous supply of the LC from the pre-illuminated regions to the adjacent non-pre-illuminated regions significantly increases the diffraction efficiency of the grating sample. This study provides an insight into developing new external-voltage-free DEP-based devices that can be applied on various fields, such as photonics, displays, and biomedicines.

Original languageEnglish
Article number202
Issue number7
Publication statusPublished - 2017 Jul

All Science Journal Classification (ASJC) codes

  • Chemical Engineering(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Inorganic Chemistry

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