Fig. 2: Gear trains powered by metarotors.
a–d SEM images (top panels) and optical microscopy images (bottom panels) of metarotors acting as driving gears that propel passive gears with varying diameters (b–d). The rotation of the metarotors is indicated by the red arrows, while the rotation of the driven gear is indicated by the white arrows. e The average ratio of angular velocity between the driving gear (ωm) and the driven gear (ωp) depends on the ratio of their diameters. f–h SEM images (top panels) and optical microscopy images (bottom panels) of a single driving gear actuating a train of driven gears with the same diameter: f N = 3, g N = 4, and h N = 5 total gears (including the driving gear) with the same diameter Dm = Dp. i The angular velocity of the driven gears ω = ωm = ωp versus the number N of gears in the gear train. The dashed line represents ω/N. The optical microscopy images are from Supplementary Video 6. Error bars in e and i represent standard deviation from three measurements for each condition. Scale bars: 10 μm.
