Optical trapping and orientation manipulation of 2D inorganic materials using a linearly polarized laser beam

Tominaga, Makoto; Higashi, Yuki; Kumamoto, Takuya; Nagashita, Takashi; Nakato, Teruyuki; Suzuki, Yasutaka; Kawamata, Jun

Because inorganic nanosheets, such as clay minerals, are anisotropic, the manipulation of nanosheet orientation is an important challenge in order to realize future functional materials. In the present study, a novel methodology for nanosheet manipulation using laser radiation pressure is proposed. When a linearly polarized laser beam was used to irradiate a niobate (Nb6O17 4-) nanosheet colloid, the nanosheet was trapped at the focal point so that the in-plane direction of the nanosheet was oriented parallel to the propagation direction of the incident laser beam so as to minimize the scattering force. In addition, the trapped nanosheet was aligned along the polarization direction of the linearly polarized laser beam. Thus, unidirectional alignment of a nanosheet can be achieved simply by irradiation using a laser beam.

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