1
|
Tone CM, Zizzari A, Spina L, Bianco M, De Santo MP, Arima V, Barberi RC, Ciuchi F. Sunset Yellow Confined in Curved Geometry: A Microfluidic Approach. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:6134-6141. [PMID: 37072936 PMCID: PMC10157883 DOI: 10.1021/acs.langmuir.3c00275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The behavior of lyotropic chromonic liquid crystals (LCLCs) in confined environments is an interesting research field that still awaits exploration, with multiple key variables to be uncovered and understood. Microfluidics is a highly versatile technique that allows us to confine LCLCs in micrometric spheres. As microscale networks offer distinct interplays between the surface effects, geometric confinement, and viscosity parameters, rich and unique interactions emerging at the LCLC-microfluidic channel interfaces are expected. Here, we report on the behavior of pure and chiral doped nematic Sunset Yellow (SSY) chromonic microdroplets produced through a microfluidic flow-focusing device. The continuous production of SSY microdroplets with controllable size gives the possibility to systematically study their topological textures as the function of their diameters. Indeed, doped SSY microdroplets produced via microfluidics, show topologies that are typical of common chiral thermotropic liquid crystals. Furthermore, few droplets exhibit a peculiar texture never observed for chiral chromonic liquid crystals. Finally, the achieved precise control of the produced LCLC microdroplets is a crucial step for technological applications in biosensing and anticounterfeiting.
Collapse
Affiliation(s)
- Caterina Maria Tone
- Physics Department, University of Calabria, Ponte Bucci, cubo 31C, 87036 Arcavacata di Rende, CS, Italy
- CNR-Nanotec, c/o Physics Department, University of Calabria, Ponte Bucci, cubo 31C, 87036 Arcavacata di Rende, CS, Italy
| | - Alessandra Zizzari
- CNR NANOTEC - Institute of Nanotechnology, c/o Campus Ecotekne, University of Salento, via Monteroni, 73100 Lecce, Italy
| | - Lorenza Spina
- Physics Department, University of Calabria, Ponte Bucci, cubo 31C, 87036 Arcavacata di Rende, CS, Italy
- CNR-Nanotec, c/o Physics Department, University of Calabria, Ponte Bucci, cubo 31C, 87036 Arcavacata di Rende, CS, Italy
| | - Monica Bianco
- CNR NANOTEC - Institute of Nanotechnology, c/o Campus Ecotekne, University of Salento, via Monteroni, 73100 Lecce, Italy
| | - Maria Penelope De Santo
- Physics Department, University of Calabria, Ponte Bucci, cubo 31C, 87036 Arcavacata di Rende, CS, Italy
- CNR-Nanotec, c/o Physics Department, University of Calabria, Ponte Bucci, cubo 31C, 87036 Arcavacata di Rende, CS, Italy
| | - Valentina Arima
- CNR NANOTEC - Institute of Nanotechnology, c/o Campus Ecotekne, University of Salento, via Monteroni, 73100 Lecce, Italy
| | - Riccardo Cristoforo Barberi
- Physics Department, University of Calabria, Ponte Bucci, cubo 31C, 87036 Arcavacata di Rende, CS, Italy
- CNR-Nanotec, c/o Physics Department, University of Calabria, Ponte Bucci, cubo 31C, 87036 Arcavacata di Rende, CS, Italy
| | - Federica Ciuchi
- CNR-Nanotec, c/o Physics Department, University of Calabria, Ponte Bucci, cubo 31C, 87036 Arcavacata di Rende, CS, Italy
| |
Collapse
|
2
|
Du X, Yang F, Liu Y, Gleeson HF, Luo D. Light-Driven Dynamic Hierarchical Architecture of Three-Dimensional Self-Assembled Cholesteric Liquid Crystal Droplets. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:1611-1618. [PMID: 36662286 DOI: 10.1021/acs.langmuir.2c03040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Cholesteric liquid crystals have attracted much attention in biosensors, in communication systems, security identification, hierarchical materials assembly, and microlasers, due to their complex and interesting structures accompanied by particular optical properties making them low-cost, label-free and sensitive. However, the reports of CLC droplets with stable topological configurations are still very limited, which hinders the fast development and broad application of CLC droplet-based devices. In this paper, we manifest light-driven changes in the topological configuration of cholesteric liquid crystals droplets, examined experimentally. Photoresponsive azo-LC doped CLC droplets were manipulated by irradiation by UV light to form novel topological configurations with stable 3D structures. The phenomenon behind the configuration changes is the light-induced cholesteric-isotropic phase transition that takes place in liquid crystals. Several topological configurations of CLC droplets have been demonstrated such as closed-ring structures with cone-shaped centers and concentric elliptical centers, and open-ring structures formed under unidirectional illumination of UV light. Structures with parallel CLC pitch lines at the center and with a central point singularity are also formed under multidirectional illumination. The competition of the elastic energy and surface energy of the CLC droplets results in the formation of the new topological configurations. All proposed configurations are stable and controllable by light, which enable CLC droplets with novel topological structures with new characteristics and provide a lot of potential applications in biosensors and microlasers.
Collapse
Affiliation(s)
- Xiaoxue Du
- Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen518055, China
- School of Physics and Astronomy, University of Leeds, LeedsLS2 9JT, U.K
| | - Fei Yang
- Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen518055, China
| | - Yanjun Liu
- Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen518055, China
| | - Helen F Gleeson
- School of Physics and Astronomy, University of Leeds, LeedsLS2 9JT, U.K
| | - Dan Luo
- Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen518055, China
| |
Collapse
|
3
|
Oswald P, Poy G, Krishnamurthy KS. Structure and Lehmann rotation of drops in a surfactant-doped bent-core liquid crystal. Phys Rev E 2022; 106:024705. [PMID: 36110001 DOI: 10.1103/physreve.106.024705] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 07/25/2022] [Indexed: 06/15/2023]
Abstract
The structure of the nematic (cholesteric) drops that form at the clearing temperature of a mixture of the bent-core molecule CB7CB and the rodlike molecule 8CB doped with a surfactant is optically determined. Using experimental observations and numerical simulations, it is demonstrated that the director field inside these drops is not escaped concentric, as previously proposed, but twisted bipolar. The Lehmann rotation of these drops in the presence of a temperature gradient is described. Their rotation velocity is shown to be proportional to the temperature gradient and to the surface twist angle of the director field and inversely proportional to the drop radius, thus revealing a fundamental scaling law for the Lehmann effect of nematic and cholesteric twisted-bipolar droplets.
Collapse
Affiliation(s)
- Patrick Oswald
- Université de Lyon, ENS de Lyon, Université Claude Bernard, CNRS, Laboratoire de Physique, F-69342 Lyon, France
| | - Guilhem Poy
- L2C, Univ Montpellier, CNRS, Montpellier, France
| | | |
Collapse
|
4
|
Patterned-Liquid-Crystal for Novel Displays. CRYSTALS 2022. [DOI: 10.3390/cryst12020185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The “Patterned-Liquid-Crystal for Novel Displays” is a Special Issue focused on new insights and explorations in the field of liquid crystals arranged in a periodic patterned way [...]
Collapse
|
5
|
Zhang M, Shahsavan H, Guo Y, Pena-Francesch A, Zhang Y, Sitti M. Liquid-Crystal-Elastomer-Actuated Reconfigurable Microscale Kirigami Metastructures. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2008605. [PMID: 33987863 PMCID: PMC7612660 DOI: 10.1002/adma.202008605] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/26/2021] [Indexed: 05/02/2023]
Abstract
Programmable actuation of metastructures with predesigned geometrical configurations has recently drawn significant attention in many applications, such as smart structures, medical devices, soft robotics, prosthetics, and wearable devices. Despite remarkable progress in this field, achieving wireless miniaturized reconfigurable metastructures remains a challenge due to the difficult nature of the fabrication and actuation processes at the micrometer scale. Herein, microscale thermo-responsive reconfigurable metasurfaces using stimuli-responsive liquid crystal elastomers (LCEs) is fabricated as an artificial muscle for reconfiguring the 2D microscale kirigami structures. Such structures are fabricated via two-photon polymerization with sub-micrometer precision. Through rationally designed experiments guided by simulations, the optimal formulation of the LCE artificial muscle is explored and the relationship between shape transformation behaviors and geometrical parameters of the kirigami structures is build. As a proof of concept demonstration, the constructs for temperature-dependent switching and information encryption is applied. Such reconfigurable kirigami metastructures have significant potential for boosting the fundamental small-scale metastructure research and the design and fabrication of wireless functional devices, wearables, and soft robots at the microscale as well.
Collapse
Affiliation(s)
- Mingchao Zhang
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, China
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
| | - Hamed Shahsavan
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
- Department of Chemical Engineering and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Yubing Guo
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
| | - Abdon Pena-Francesch
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
- Department of Materials Science and Engineering, Macromolecular Science and Engineering, Robotics Institute, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Yingying Zhang
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Metin Sitti
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569, Stuttgart, Germany
- Institute for Biomedical Engineering, ETH Zürich, Zürich, 8092, Switzerland
- School of Medicine and School of Engineering, Koç University, Istanbul, 34450, Turkey
| |
Collapse
|