Optical forces arising from momentum exchange during light–matter interactions have become indispensable tools in biophysics, soft matter science and micro- and nanofabrication. Among these, optical conveyors—capable of generating stable, directional optical flows—enable nanoparticle transport along predefined trajectories, offering unique advantages for drug delivery, cell sorting, and lab-on-a-chip systems. However, conventional platforms often rely on spatial light modulators to produce dynamic holograms. Such systems are bulky, constrained by limited pixel size and count, and difficult to integrate—factors that severely impede practical deployment.

Metasurfaces have recently opened new pathways for miniaturizing optical manipulation devices, thanks to their subwavelength field-shaping capabilities. Yet, most existing metasurface-based schemes still depend on radially or azimuthally uniform phase gradients, which confine the resulting optical flow to closed loops (vortex rings) due to the intrinsic geometry of vortex fields.

Real-world applications—such as guiding a particle around an obstacle within a microfluidic chip—urgently demand conveyors with open paths. Moreover, a complete optical conveyor should support three independent motion modes: forward, stop, and backward. This requires encoding at least three parallel channels onto a single metasurface.