TY  - JOUR
AU  - Kokot, Gašper
AU  - Das, Shibananda
AU  - Winkler, Roland G.
AU  - Gompper, Gerhard
AU  - Aranson, Igor S.
AU  - Snezhko, Alexey
TI  - Active turbulence in a gas of self-assembled spinners
JO  - Proceedings of the National Academy of Sciences of the United States of America
VL  - 114
IS  - 49
SN  - 1091-6490
CY  - Washington, DC
PB  - National Acad. of Sciences
M1  - FZJ-2017-08106
SP  - 12870 - 12875
PY  - 2017
AB  - Colloidal particles subject to an external periodic forcing exhibit complex collective behavior and self-assembled patterns. A dispersion of magnetic microparticles confined at the air–liquid interface and energized by a uniform uniaxial alternating magnetic field exhibits dynamic arrays of self-assembled spinners rotating in either direction. Here, we report on experimental and simulation studies of active turbulence and transport in a gas of self-assembled spinners. We show that the spinners, emerging as a result of spontaneous symmetry breaking of clock/counterclockwise rotation of self-assembled particle chains, generate vigorous vortical flows at the interface. An ensemble of spinners exhibits chaotic dynamics due to self-generated advection flows. The same-chirality spinners (clockwise or counterclockwise) show a tendency to aggregate and form dynamic clusters. Emergent self-induced interface currents promote active diffusion that could be tuned by the parameters of the external excitation field. Furthermore, the erratic motion of spinners at the interface generates chaotic fluid flow reminiscent of 2D turbulence. Our work provides insight into fundamental aspects of collective transport in active spinner materials and yields rules for particle manipulation at the microscale.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000417339700023
C6  - pmid:29158382
DO  - DOI:10.1073/pnas.1710188114
UR  - https://juser.fz-juelich.de/record/840601
ER  -