An Optically Driven Bistable Janus Rotor with Patterned Metal Coatings.
Bistable rotation is realized for a gold-coated Janus colloidal particle in an infrared optical trap. The metal coating on the Janus particles are patterned by sputtering gold on a monolayer of closely packed polystyrene particles. The Janus particle is observed to stably rotate in an optical trap. Both the direction and the rate of rotation can be experimentally controlled. Numerical calculations reveal that the bistable rotation is the result of spontaneous symmetry breaking induced by the uneven curvature of the coating patterns on the Janus sphere. Our results thus provide a simple method to construct large quantities of fully functional rotary motors for nano- or microdevices.
Beijing National Laboratory for Condensed Matter Physics and Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
Yiwu
Y
Zong
Beijing National Laboratory for Condensed Matter Physics and Key Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
Jing
J
Liu
Beijing National Laboratory for Condensed Matter Physics and Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
Rui
R
Liu
Beijing National Laboratory for Condensed Matter Physics and Key Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
Honglian
H
Guo
Beijing National Laboratory for Condensed Matter Physics and Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
Mingcheng
M
Yang
Beijing National Laboratory for Condensed Matter Physics and Key Laboratory of Optical Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
Zhiyuan
Z
Li
Beijing National Laboratory for Condensed Matter Physics and Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
Ke
K
Chen
Janus particles; controlled rotation; microrotor; optical traps; spontaneous symmetry breaking