Journal of Applied Science and Engineering

Published by Tamkang University Press


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Pin-Chun Huang1, Yung-Ta Huang1, Fu-Ling Yang1 and Wen-Pin Shih This email address is being protected from spambots. You need JavaScript enabled to view it.1

1Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan 106, R.O.C.


Received: June 6, 2016
Accepted: June 17, 2016
Publication Date: December 1, 2016

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Nematic liquid crystals with orientational order can be disturbed by electromagnetic fields, thermal gradients, and other forces. Here we demonstrated that the orientation of nematic liquid crystal molecules is influenced by the motion of colloidal particles subjected to a centrifugal force. The associated dynamics of the colloidal particles dispersed in nematic liquid crystals was also derived. The capacitance of the paricles/liquid crystal dispersion changes once its angular velocity exceeds a threshold dominated by the elastic force of the liquid crystal. Both numerical derivation and experiment showed that the elastic trapping force is associated with elastic energy and anchoring energy of particle surface. Furthermore, the hysteresis capacitance increases with increasing differential capacitance of the liquid crystals but is affected by the particle mobility. The characteristic of realigning the director by the changing rotational velocity offers numerous sensing applications, and the force mechanisms exerting on colloidal particles in nematic liquid crystals can be applied to biotechnology, microfluidic applications, or manipulation of the colloidal particles transport in anisotropic liquid.

Keywords: Nematic Liquid Crystal, Colloidal Particle, Elastic Trapping Force, Rotational Dynamics


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