Polarization of asymmetric surfaces and asymmetric particles under an electric field
Hong-Ren Jiang1*
1Institute of Applied Mechanics, National Taiwan University, Taipei, Taiwan
* Presenter:Hong-Ren Jiang, email:hrjiang@iam.ntu.edu.tw
In this report, the dynamics of polarization of asymmetric surfaces and asymmetric colloidal particles under an electric field will be discussed. The polarization characteristics of asymmetric particles under a rotating electric field are experimentally measured by electrorotation and compared with simulations. A variety of designs of multilayer Janus particles were prepared and the relationship between the electric double layer and the electrorotation of particles will be covered. We find that the time scale of electric double layer polarization would affect the directionality of the rotation of the particles. The reversals of the rotations are found both in low and high frequency region. Possible sensing applications through electrorotation are also proposed. In a non-rotating AC electric field, the motion of various asymmetric particles and their surrounding flow are also discussed by the polarization of the electric double layer. A unidirectional flow generated by AC electric field on an asymmetry of surface is proposed.

Keywords: non-equilibrium soft matter, Janus particle , ICEO, electrorotation