  Nature has evolved a vast array of strategies for propulsion at the air-fluid
interface. Inspired by a survival mechanism initiated by the honeybee (Apis
mellifera) trapped on the surface of water, we here present the SurferBot: a
centimeter-scale vibrating robotic device that self-propels on a fluid surface
using analogous hydrodynamic mechanisms as the stricken honeybee. This low-cost
and easily assembled device is capable of rectilinear motion thanks to forces
arising from a wave-generated, unbalanced momentum flux, achieving speeds on
the order of centimeters per second. Owing to the dimensions of the SurferBot
and amplitude of the capillary wave field, we find that the magnitude of the
propulsive force is similar to that of the honeybee. In addition to a detailed
description of the fluid mechanics underpinning the SurferBot propulsion, other
modes of SurferBot locomotion are discussed. More broadly, we propose that the
SurferBot can be used to explore fundamental aspects of active and driven
particles at fluid interfaces, as well as in robotics and fluid mechanics
pedagogy.
