Figure 6.

Photothermal effect-induced swarming and assembly of CPs. (A) Schematic demonstration of the self-propulsion and mutual interactions of metal-coated Janus spheres produced by the long-ranged temperature profiles due to light irradiation (reproduced from [81]); (B) CPs move ballistically to the cold surface in a temperature gradient induced by laser irradiation. The surface deflects the persisting slip flow and leads to mutual hydrodynamic attraction (a), resulting in the thermophoretic crystallization of PS CPs (b). Inset in b: the state of the particles before the presence of the temperature gradient (reproduced from [67]); (C) schematic diagram of the assembly and disassembly of positively charged Au nanotriangles with the laser on and off (reproduced from [83]); (D) 1D, 2D, and 3D hybrid assembly of 2 and 0.96 μm PS beads and anisotropic PS particles based on opto-thermophoresis; Scale bars, 5 μm (1–4) and 2 μm (5) (reproduced from [84], reprinted with permission from AAAS).