TOPACT · Topological defects in nematic liquid crystals of active colloidal rods
„Хоризонт 2020“ — Действия „Мария Склодовска-Кюри“
- Период
- 2016-03-08 → 2018-03-07
- Финансиране от ЕС
- 195 455 €
- Участници
- 1
- Схема
- MSCA-IF
Линиите свързват координатора с партньорите.
Накратко на български
Активни колоидни частици в течни кристали се анализират чрез електрическо поле, за да се имитират системи като пасажи от риби или ята птици. Това помага за разбирането на физичните механизми, които управляват колективното движение на големи групи обекти.
Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.
Резултати накратко
Topological defects in nematic liquid crystals of active colloidal rods
Many living cells and organisms are active: they can move in a certain direction using a chemical fuel. The characteristics of systems that contain active objects is fundamentally different from passive materials. In dense active matter systems, for example, the out-of-equilibrium nature of the system and the self-organisation of the constituents give rise to intriguing collective dynamics: collective swirling motion, macroscopic fluid flows and giant density fluctuations. Such dynamics has been observed in schools of fish, flocks of birds, films of bacteria and myosin motors on actin filaments. However, the physical mechanisms underlying these collective effects in dense active matter systems remain poorly understood. An important bottleneck in current efforts to unravel these physical effects and to study collective dynamics in active matter is the lack of reliable experimental model systems for dense active matter. To overcome this limitation, we developed a well-defined experimental model system of active colloids and studied this at the single-particle level. The active particles are enclosed in a thin optical cell with electrodes at the top and bottom to control the activity of the particles by means of an oscillating electric field. Analysis of the activity, orientation and interactions of every particle in these active systems will help gain more insight in the physical mechanisms that underlie collective effects in large groups of active objects, such as schools of fish and flocks of birds.
Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз
Цел на проекта
Active liquid crystals are out-of-equilibrium systems that display intriguing dynamic phenomena, arising from the interplaybetween topological defects and collective motion. Here, we propose to experimentally study for the first time (i) thedynamics of topological defects in the active colloidal nematic phase and (ii) the interplay between these topological defectsand collective dynamics, in three dimensions, at the single particle level, and with full control over the defects. To reachthese objectives, we first use a combination of advanced colloidal synthesis and surface modification techniques in order todevelop a model system of active colloidal rods of controlled size, aspect ratio and surface properties. We then confine thisnewly developed model system in microfluidic channels, where the colloidal rods form a nematic liquid crystal. Topologicaldefects will be induced in the nematic phase using specific geometric constraints, which can be varied to control thelocations and strengths of the defects, or by optical trapping techniques. Finally, we use state-of-the-art confocal microscopyand sophisticated image analysis techniques to follow, in real time and 3D real space, both the individual particle motion andthe collective dynamics in the system. Our work will thus provide experimental verification of the intriguing link betweentopological defects and collective dynamics in active liquid crystals and inspire novel theories and simulation codes capableof capturing the intrinsic complexity of coupling structure, orientation and activity.
Оригинален текст от CORDIS (на английски).
Участници
- THE CHANCELLOR, MASTERS AND SCHOLARS OF THE UNIVERSITY OF OXFORD · OxfordКоординаторОбединеното кралство
Връзки
Данни: CORDIS, © Европейски съюз