Light actuated swarming and breathing-like motion of graphene oxide colloidal particles

Hong Qin,Xiaoran Wu,Xiang Xue,Hewen Liu

doi:10.1038/s42004-018-0073-4

Hong Qin, Xiaoran Wu + Show 2 more

Open Access

https://doi.org/10.1038/s42004-018-0073-4

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Abstract

Synthetic microparticles that can be propelled under light stimulus and generate collective behaviors via interaction among these particles may lead to applications in numerous fields. Here we show that aqueous graphene oxide (GO) particles can move autonomously to a light source. These self-propelled multilayer GO particles swarm but periodically “stop to take a breath” under continuous light stimulus. UV light causes a movement velocity of approximately 25 μm s−1 and oscillating frequency of approximately two times per minute for multilayer GO particles. Light with a wavelength longer than green light causes neither locomotion nor oscillation. Only multilayer GO particles exhibit the oscillating behavior. This unusual oscillating mode suggests that multilayer GO particles may undergo non-equilibrium dynamic processes in their light-actuated collective motion.

Highlights

Synthetic microparticles that can be propelled under light stimulus and generate collective behaviors via interaction among these particles may lead to applications in numerous fields
The dispersed and the precipitated graphene oxide (GO) particles showed different mean thicknesses measured with atomic force microscopy (AFM) by averaging over images of randomly chosen ~ 100 platelets, according to the method reported in the literature (Fig. 1)[24]
We carried out the X-ray diffraction (XRD) analysis on the dry samples of the dispersed and the precipitated GO particles (Fig. 1)

Summary

Introduction

Synthetic microparticles that can be propelled under light stimulus and generate collective behaviors via interaction among these particles may lead to applications in numerous fields. We show that aqueous graphene oxide (GO) particles can move autonomously to a light source These self-propelled multilayer GO particles swarm but periodically “stop to take a breath” under continuous light stimulus. Multilayer GO particles exhibit the oscillating behavior This unusual oscillating mode suggests that multilayer GO particles may undergo non-equilibrium dynamic processes in their light-actuated collective motion. Self-propelled colloidal particles have continuously attracted broad interests in various fields including materials sciences, surface/interface sciences, biophysics and fluid mechanics[1,2,3,4,5], because that the self-propelled colloid particles have potential applications in small smart devices, self-adaptive catalyst systems, etc[6,7,8,9,10], and because that their collective motion can generate order far from equilibrium[11,12,13]. We find that multilayer GO colloidal particles can autonomously swarm and periodically “stop to take a breath” synchronously under continuous light stimulus

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