Review
Chemistry, Multidisciplinary
Maria Penelope De Santo, Lorenza Spina, Federica Ciuchi
Summary: Chromonic liquid crystals have attracted attention due to their self-assembly in supramolecular structures and the possibility to induce chirality. This review focuses on the research on chiral chromonic liquid crystals confined in spherical geometry and compares the results with thermotropic liquid crystals. The effects of different anchoring conditions and chiral dopants on the topologies of commercially available nematic chromonics are investigated, suggesting a potential application in the sensor field.
APPLIED SCIENCES-BASEL
(2023)
Article
Chemistry, Multidisciplinary
Tejal Pawale, Justin Swain, Mohammad Reza Hashemi, Giordano Tierra, Xiao Li
Summary: Topological defects have significant influence on the characteristics of materials and liquid crystals provide an ideal system to study them. The effects of surface patterns on the dynamics, stabilization, and annihilation of defects are explored through computational experiments. The approach offers a promising opportunity to control the dynamics of defects in liquid crystals through chemical patterned surfaces.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Biochemistry & Molecular Biology
Bingrui Liu, Li Cheng, Yuan Yuan, Jian Hu, Lijuan Zhou, Lu Zong, Yongxin Duan, Jianming Zhang
Summary: In this study, the organization features of cellulose nanospheres (CNSs) were investigated. It was found that above a critical concentration, CNSs can organize into a liquid-crystal phase consisting of parallel-aligned layer structures, which persist after drying. Compared to cellulose nanorods (CNRs), CNSs exhibit shorter layer distance, lower order degree, and weaker long-range orientation. Additionally, a caterpillar-like model was proposed to explain the early stages of tactoid formation, serving as the fundamental unit for further liquid-crystal assembly.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2023)
Article
Physics, Multidisciplinary
Joseph Pollard, Gareth P. Alexander
Summary: This article gives a description of the intrinsic geometry of elastic distortions in three-dimensional nematic liquid crystals and establishes necessary and sufficient conditions for a set of functions to represent these distortions by describing how they couple to the curvature tensor. It is shown that, unlike in two dimensions, the first-order gradients of the director alone are not sufficient for full reconstruction of the director field from its intrinsic geometry and additional information about the second-order director gradients is necessary. Furthermore, various methods for reconstructing the director field from its intrinsic geometry are described, and the coupling between individual distortions and curvature is discussed from the perspective of Lie algebras and groups, along with the description of homogeneous spaces where pure modes of distortion can be realized.
NEW JOURNAL OF PHYSICS
(2021)
Article
Multidisciplinary Sciences
Hamed Abbaszadeh, Michel Fruchart, Wim van Saarloos, Vincenzo Vitelli
Summary: Liquid crystals provide exquisite control of light propagation due to their orientational order and optical anisotropy. By utilizing spatial variations in the orientation of nematic liquid-crystal molecules and suitable structural properties, topologically protected states of light can be created. The soft photonic realizations of iconic topological systems offer potential for reconfigurable systems exploiting the interplay between topological states of light and the medium.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Review
Optics
Hakam Agha, Yong Geng, Xu Ma, Deniz Isinsu Avsar, Rijeesh Kizhakidathazhath, Yan-Song Zhang, Ali Tourani, Hriday Bavle, Jose-Luis Sanchez-Lopez, Holger Voos, Mathew Schwartz, Jan P. F. Lagerwall
Summary: The molding of cholesteric liquid crystal into a spherical shape creates Cholesteric Spherical Reflectors (CSRs), which have significant optical consequences and potential applications. The omnidirectional chiral Bragg diffraction of CSRs makes them easily distinguishable retroreflectors using machine vision, while also being imperceptible to human vision. This opens up opportunities for various transformative technologies and their integration into human-populated environments.
LIGHT-SCIENCE & APPLICATIONS
(2022)
Article
Multidisciplinary Sciences
Sebastian Echeverria-Alar, Marcel G. Clerc, Ignacio Bordeu
Summary: Spatial branching processes are observed in chiral nematic liquid crystals, where a cholesteric phase self-organizes into extended branching patterns. We study the spatial and temporal organization of thermally driven branching patterns in chiral nematic liquid crystal cells experimentally, and describe the observations using a mean-field model.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Optics
Weipeng Hu, Jiali Hu, Shuangchun Wen, Yuanjiang Xiang
Summary: Dynamic tunable and reconfigurable topological states have been achieved in higher-order topological insulators with liquid crystal technology, offering new possibilities for optical devices.
Article
Mathematics, Applied
Athena Papargiri, Vasileios S. Kalantonis, Panayiotis Vafeas, Michael Doschoris, Foteini Kariotou, George Fragoyiannis
Summary: The forward electroencephalography (EEG) problem is studied using a multi-layered structure to represent the scalp, skull, cerebrospinal fluid, and brain. The study focuses on localized defects in head-brain imaging and uses linear perturbation analysis to provide an exact expression for the first significant term of the forward EEG solution. The results show that significant errors occur when inaccuracies in the head-brain structure near the EEG source are overlooked.
MATHEMATICAL METHODS IN THE APPLIED SCIENCES
(2022)
Article
Chemistry, Multidisciplinary
Sylwia Parzyszek, Jacopo Tessarolo, Adrian Pedrazo-Tardaos, Ana M. Ortuno, Maciej Baginski, Sara Bals, Guido H. Clever, Wiktor Lewandowski
Summary: This study proposes a strategy to achieve strongly dissymetric CPL in nanocomposite films based on chiroptical induction and energy transfer to semiconductor nanocrystals. By controlling the chirality of helical nanofilaments in liquid crystal matrix and adjusting energy transfer from organic films to quantum dots, CPL wavelengths can be conveniently tuned. This approach provides a simple and versatile method to modulate the CPL activity of organic materials.
Article
Chemistry, Physical
Cheng Long, Jonathan V. Selinger
Summary: Many materials exhibit geometric frustration due to the compromise between ideal local structure and geometric constraints. This paper investigates the structures formed by chiral liquid crystals under different spatial constraints, and analyzes the relative free energies using theory and simulations.
Article
Multidisciplinary Sciences
Miha Papic, Urban Mur, Kottoli Poyil Zuhail, Miha Ravnik, Igor Musevic, Matjaz Humar
Summary: Liquid crystals can form a variety of self-assembled topological structures with applications in optical and photonic devices, exhibiting unique properties such as self-assembly, self-healing, large tunability, sensitivity to external stimuli, and biocompatibility. By inserting topological defects into LC superstructures, complex tunable microlasers emitting structured light can be generated, with the topology and geometry of the LC superstructure determining the structuring of the emitted light.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Multidisciplinary Sciences
Richard J. Mandle
Summary: This article describes a lightweight Python tool called cylindr for calculating the cylindrical distribution function. It can be used for analyzing positional correlations within anisotropic systems like liquid crystals.
Article
Chemistry, Multidisciplinary
Divya Varadharajan, Karthik Nayani, Christoph Zippel, Eduard Spuling, Kenneth C. Cheng, Swetha Sarangarajan, Sangchul Roh, John Kim, Vanessa Trouillet, Stefan Braese, Nicholas L. Abbott, Joerg Lahann
Summary: Mesoscale chiral materials can be prepared by chemical vapor deposition, resulting in superhierarchical arrangements of enantiomorphically pure nanofibers, which depend on the molecular structure and purity of the chiral precursors.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Physical
Shuliang Ren, Changji Liu, Kaixuan Xu, Nai Jiang, Fangrong Hu, Ping-Heng Tan, Houzhi Zheng, Xinlong Xu, Chao Shen, Jun Zhang
Summary: In this study, experimental investigations were conducted on the azimuth-dependent circular dichroism (CD) spectra of achiral metamaterials, which showed good agreement with simulation results. The origin of the CD was explained by the coupling of macroelectric dipole and magnetic dipole, providing a potential method for constructing on-chip azimuth sensors based on CD spectra of metamaterials.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Editorial Material
Chemistry, Physical
Olivier Dauchot, Hartmut Loewen
JOURNAL OF CHEMICAL PHYSICS
(2019)
Article
Physics, Multidisciplinary
Marjolein N. van der Linden, Lachlan C. Alexander, Dirk G. A. L. Aarts, Olivier Dauchot
PHYSICAL REVIEW LETTERS
(2019)
Article
Physics, Multidisciplinary
Mathias Casiulis, Marco Tarzia, Leticia F. Cugliandolo, Olivier Dauchot
PHYSICAL REVIEW LETTERS
(2020)
Article
Physics, Multidisciplinary
Pavan V. Kashyap, Yohann Duguet, Olivier Dauchot
News Item
Physics, Multidisciplinary
Olivier Dauchot
Article
Physics, Multidisciplinary
Rahul N. Chacko, Francois P. Landes, Giulio Biroli, Olivier Dauchot, Andrea J. Liu, David R. Reichman
Summary: As liquids approach the glass transition temperature, dynamical heterogeneity becomes a crucial universal feature of their behavior. Dynamic facilitation, where local motion triggers further motion nearby, is a major player in this phenomenon. Long-ranged, elastically mediated facilitation appears below the mode coupling temperature, in addition to the short-range component present at all temperatures. These results suggest strong connections between the supercooled liquid and glass states, laying the groundwork for a deeper understanding of dynamical heterogeneity in glassy systems.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Juliane U. Klamser, Olivier Dauchot, Julien Tailleur
Summary: The study reveals that for kinetic Monte Carlo descriptions of active particles, a continuous-time limit is ill-defined when relying solely on persistent, active steps. However, mixing passive steps with active ones can lead to a well-defined continuous-time limit. New KMC algorithms are proposed to obtain dynamics of active Ornstein-Uhlenbeck, active Brownian, and run-and-tumble particles.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
P. Baconnier, D. Shohat, C. Hernandez Lopez, C. Coulais, V Demery, G. During, O. Dauchot
Summary: This study introduces a minimal realization of an active elastic solid and characterizes the emergence of selective and collective actuation resulting from the interplay between activity and elasticity. The bifurcation scenario and selection mechanism by which the collective actuation takes place are unveiled through experiments and theoretical analyses.
Article
Physics, Multidisciplinary
Pavan V. Kashyap, Yohann Duguet, Olivier Dauchot
Summary: The formation of laminar-turbulent pattern is a distinctive feature of the intermittency regime in subcritical plane shear flows. Through extensive numerical simulations, it is shown that the pattern arises from a spatial modulation of turbulent flow due to linear instability. By sampling the linear response of turbulent field to a temporal impulse, the dispersion relation is constructed from ensemble-averaged relaxation rates. As the instability threshold is approached, the relaxation rate of the least damped modes eventually reaches zero.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Paul Baconnier, Dor Shohat, Olivier Dauchot
Summary: The recent finding of collective actuation in active solids provides new possibilities for the design of multifunctional materials and the understanding of biological systems. The study combines experimental and numerical approaches to reveal a new form of collective actuation and highlight the role of mechanical tension in transitioning between different actuation regimes. The presence of hysteresis emphasizes the nontrivial selectivity of collective actuations.
PHYSICAL REVIEW LETTERS
(2023)
Article
Chemistry, Physical
Nuno A. M. Araujo, Liesbeth M. C. Janssen, Thomas Barois, Guido Boffetta, Itai Cohen, Alessandro Corbetta, Olivier Dauchot, Marjolein Dijkstra, William M. Durham, Audrey Dussutour, Simon Garnier, Hanneke Gelderblom, Ramin Golestanian, Lucio Isa, Gijsje H. Koenderink, Hartmut Loewen, Ralf Metzler, Marco Polin, C. Patrick Royall, Andela Saric, Anupam Sengupta, Cecile Sykes, Vito Trianni, Idan Tuval, Nicolas Vogel, Julia M. Yeomans, Iker Zuriguel, Alvaro Marin, Giorgio Volpe
Summary: Self-organisation is the spontaneous emergence of spatio-temporal structures and patterns from the interaction of smaller individual units. Confinement can mediate and control self-organisation by limiting the translational and rotational degrees of freedom, acting as a catalyst or inhibitor. By constraining the self-organisation process in soft-matter systems, confinement can actively steer the emergence or suppression of collective phenomena in space and time.
Article
Robotics
Matan Yah Ben Zion, Jeremy Fersula, Nicolas Bredeche, Olivier Dauchot
Summary: We present a mechanical design rule that enables robots to operate in a collision-dominated environment. By encoding a reorientation response to external forces in a three-dimensional printed exoskeleton, we enhance the motility and stability of individual robots and leverage steric interactions for collective behavior. This mechanical layer adds to the robot's sense-act cycle at the swarm level and promotes information flow for online distributed learning.
Article
Physics, Fluids & Plasmas
Caleb J. Anderson, Guillaume Briand, Olivier Dauchot, Alberto Fernandez-Nieves
Summary: The configurations of polymers in out-of-equilibrium baths have implications in biological systems. Comparing with thermal-like baths, active baths affect the polymer's Kuhn length and lead to more prominent bends in their configurations.
Article
Chemistry, Physical
Charlotte de Blois, Vincent Bertin, Saori Suda, Masatoshi Ichikawa, Mathilde Reyssat, Olivier Dauchot
Summary: The behavior of self-propelled water-in-oil droplets in capillaries of different cross-sections was experimentally investigated. It was found that the velocity of the droplet decreases with increasing confinement in straight capillaries, but even very long droplets can still swim at very high confinement. In stretched circular capillaries, the non-uniform thickness of the lubrication layer around the droplet leads to neck formation and eventual spontaneous splitting events for large enough confinement, highlighting the critical role of the droplet's interface activity under confinement.
Article
Physics, Fluids & Plasmas
Pierre Illien, Charlotte de Blois, Yang Liu, Marjolein N. van der Linden, Olivier Dauchot