Assembling of three-dimensional crystals by optical depletion force induced by a single focused laser beam

作者:Deng, Hai-Dong; Li, Guang-Can; Liu, Hai-Ying; Dai, Qiao-Feng; Wu, Li-Jun; Lan, Sheng*; Gopal, Achanta Venu; Trofimov, Vyacheslav A.; Lysak, Tatiana M.
来源:Optics Express, 2012, 20(9).
DOI:10.1364/OE.20.009616

摘要

We proposed a method to assemble microspheres into a three-dimensional crystal by utilizing the giant nonequilibrium depletion force produced by nanoparticles. Such assembling was demonstrated in a colloid formed by suitably mixing silica microspheres and magnetic nanoparticles. The giant nonequilibrium depletion force was generated by quickly driving magnetic nanoparticles out of the focusing region of a laser light through both optical force and thermophoresis. The thermophoretic binding of silica beads is so tight that a colloidal photonic crystal can be achieved after complete evaporation of solvent. This technique could be employed for fabrication of colloidal photonic crystals and molecular sieves.