Directed rotation of a symmetric gear driven by visual-perception-dependent particles

Rotational motor is a long-standing issue because of its important theoretical and practical implications. Previous works revealed that driving gears in reciprocal systems requires either asymmetry in the gears or chirality in the particles. However, using numerical simulations, we have demonstrated that visual-perception-dependent particles (VPDPs) with visual misalignment can induce the ratchet effect of symmetric gears in the absence of chirality. Visual-perception dependence is accompanied by non-reciprocity due to the limited visual cones, which are widespread with living systems. The coupling of non-reciprocity and visual misalignment allows particles to form clusters with persistent swirling, resulting the directed rotation of gears. The sign of visual misalignment only affects the direction of gear rotation. The effects of perception threshold and number density on the scaled average angular velocity are non-monotonic. Interestingly, when a small visual misalignment is combined with a small perception threshold or number density, the gear can exhibit rotation reversal. Additionally, the scaled average angular velocity is a peak function of rotational diffusion coefficient for liquid-like state but not sensitive to its variety for solid-like state. Our results may enhance the understanding of self-organized behavior of the perception-dependent matter, particularly accompanying non-reciprocal interactions, and potentially advance experimental research on rotational motors.