Synchronization of self-propelled soft pendulums

Abstract

We investigated self-propelled motions of thin filaments atop water, where we focused on understanding pendulum-type oscillations and synchronization. The filaments were produced from a commercial adhesive (consisting mainly of nitrocellulose and acetone), and exhibited deformable motions. One end of each filament was held on the edge of a quadrangular water chamber while the other was left free. Acetone and other organic molecules from the nitrocellulose filament develop on the water surface and decrease the surface tension. The difference in the surface tension around the filament becomes the driving force of the self-propelled motions. When a single filament was placed in the water chamber, a pendulum-type oscillation in the deformation of the filament was observed. When two filaments were placed in parallel in the chamber, in-phase, out-of-phase, and no-synchronization motions were observed. It was found that the class of motions depends on the distance between the two fixed points of the filaments. Mathematical modeling and numerical simulations were also used in order to further understand the dynamics of the surface active molecules and the filament motions. We propose a mathematical model equation and reproduce various behaviors exhibited by soft self-propelled matters through numerical simulation.

Multidimensional Self-Propelled Motion Based on Nonlinear Science

“…The filament is produced from a commercial adhesive (consisting mainly of nitrocellulose and acetone), and the energy source is acetone and the driving force of motion is the difference in the surface tension around the filament since acetone reduces the surface tension. As the shape of the filament is deformed and oscillated periodically, information of wave propagation along the filament is added as characteristic features of motion in addition to information of mass movement [40]. When one of the end points of the single filament is fixed on the edge of the chamber, periodic pendulum motion is produced and the phase of the filament near the fixed edge progresses faster in comparison with the phase of the free edge for the pendulum motion.…”

Modes of synchrony in self-propelled pentanol drops

“…Experimental investigations of the mechanisms of coupled self-propelled drops and analysis of their behavior using the tools and techniques of nonlinear dynamics are an attractive field of research. 23 Some recent advancements in this area lead to the synchronization of a pair of nitrobenzene droplets reported by Sato et al 24 and synchronization of pinned aniline oil drops at the air–aqueous interface by Chen et al 25 Some other systems related to the synchronization of drops have been investigated in electrochemical systems, such as synchronization phenomena in autonomous mercury drops by Dinesh et al 26 and synchronization patterns in arrays of diffusively coupled self-oscillating droplets by Budroni et al 27 A few other studies include synchronization of coupled self-propelled filaments, 28 synchronization of two self-propelled flexible foils, 29 synchronized movement of two camphor boats in polygonal chambers, 30 rotational synchronization of camphor ribbons, 31,32 collective dynamics in camphor boats, 33 and periodic oscillations in strings of camphor discs. 34 But, to the best of our knowledge, no one has yet reported the coupled dynamics of self-propelled pentanol drops on an aqueous solution.…”

Spontaneous motion of a camphor particle with a triangular modification from a circle

“…Moreover, the particle shape also affects the force and torque since they result from the surface tension at the particle periphery. Actually, there have been several studies focusing on the effect of its shape or deformation [13,[19][20][21][22][23]. We also investigated the motion of an elliptic camphor particle as the most fundamental modification from a circle [24,25].…”