Actuation of shape-memory colloidal fibres of Janus ellipsoids.
Many natural micrometre-scale assemblies can be actuated to control their optical, transport and mechanical properties, yet such functionality is lacking in colloidal structures synthesized thus far. Here, we show with experiments and computer simulations that Janus ellipsoids can self-assemble into self-limiting one-dimensional fibres with shape-memory properties, and that the fibrillar assemblies can be actuated on application of an external alternating-current electric field. Actuation of the fibres occurs through a sliding mechanism that permits the rapid and reversible elongation and contraction of the Janus-ellipsoid chains by ~36% and that on long timescales leads to the generation of long, uniform self-assembled fibres. Colloidal-scale actuation might be useful in microrobotics and in applications of shape-memory materials.
1] Macromolecular Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA [2] [3].
Aayush A
AA
Shah
1] Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA [2].
Benjamin
B
Schultz
Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA.
Wenjia
W
Zhang
1] Macromolecular Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA [2] Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA [3] Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA [4] Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA.
Sharon C
SC
Glotzer
1] Macromolecular Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA [2] Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA.
Michael J
MJ
Solomon