Article
Chemistry, Physical
Lokesh K. Gangwar, Amit Choudhary, Sonal Rewri, Gautam Singh, Ashok M. Biradar, Gajjala Sumana, Rajesh
Summary: We investigated the crystallization of cholesterol in combination with ferroelectric liquid crystal (FLC) and found that the addition of cholesterol resulted in a reduction in relative dielectric permittivity and a decrease in the transition temperature from ferroelectric (chiral smectic C, SmC*) to paraelectric (chiral smectic A, SmA*) phase in FLC. Crystallized needles were observed at higher concentrations of cholesterol, and these needles exhibited optical birefringence. The needles disappeared with increasing temperature and were not present in the nematic and isotropic phases. The results suggested that the presence of cholesterol influenced the properties of FLC, and this understanding could be valuable in the development of FLC-based biosensors for cholesterol and other molecules.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Physics, Applied
Amit Choudhary, Ambika Bawa, Lokesh K. Gangwar, Surinder P. Singh, Ashok M. Biradar, Rajesh
Summary: The study shows that surface anchoring of liquid crystal molecules and cell thickness play a crucial role in low voltage operation switching. Dielectric and electro-optics investigation has confirmed the relationship between relaxation process associated with the interface and low power operation.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Chemistry, Physical
Sidra Khan, Jai Prakash, Shikha Chauhan, Amit Choudhary, Ashok M. Biradar
Summary: Dielectric spectroscopy is used to investigate the behavior of bulk mode and surface phenomenon in surface stabilized liquid crystal samples. The study reveals the significant influence of surface effect on the characteristics of GM phenomenon, as well as the presence of two molecular dynamics and mode transitions at different temperatures.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Chemistry, Multidisciplinary
S. Kumar, A. Choudhary, L. K. Gangwar, S. P. Singh, A. M. Rajesh, A. M. Biradar
Summary: The smectic layer reorientation and molecular dynamics of high-tilt angle ferroelectric liquid crystal material in surface stabilised geometry (SSFLC) were investigated using electro-optical and dielectric spectroscopy techniques. Controlled cooling rate and electric field application near the transition temperature resulted in smectic layer reorientation. Different phenomena were observed under different cooling conditions, including stripe domains, heliconical structure, and twisted structure within stripes.
Article
Optics
Esther Nabadda, Noureddine Bennis, Michal Czerwinski, Aleksandra Walewska, Leszek R. Jaroszewicz, Maria del Mar Sanchez-Lopez, Ignacio Moreno
Summary: In this work, a ferroelectric liquid crystal (FLC) modulator with a large switching rotation angle close to 90 degrees is fabricated and characterized. The modulator acts as a switchable wave-plate with an in-plane rotation of the principal axis under bipolar voltage. The device behaves as a binary pi phase modulator independently of the input state of polarization in the ideal situation of half-wave retardance. Physico-chemical properties of the liquid crystalline mixture used to fabricate the FLC modulator with such a large switching angle are provided. The device optical properties are characterized, and the polarization-independent pi phase shift is demonstrated using an adapted Young's type interferometer.
OPTICS AND LASERS IN ENGINEERING
(2022)
Article
Materials Science, Multidisciplinary
Dong Wook Lee, Hae-Chang Jeong, Dong Hyun Kim, Jin Young Oh, Yang Liu, Dae-Shik Seo
Summary: Uniform liquid crystal alignment can be achieved on PEVA films through ion-beam irradiation, and this method can be used for future LC display applications.
Article
Chemistry, Multidisciplinary
Wei-Qiang Liao, Bin-Bin Deng, Zhong-Xia Wang, Ting-Ting Cheng, Yan-Ting Hu, Shu-Ping Cheng, Ren-Gen Xiong
Summary: SA-PFA is an organic molecular ferroelectric material with light-triggered reversible structural changes, showing clear ferroelectricity and optically induced ferroelectric polarization switching behavior. The reversible photoisomerization effect of SA-PFA enables potential application in light-controlled ferroelectric devices.
Article
Multidisciplinary Sciences
Xi Chen, Eva Korblova, Matthew A. Glaser, Joseph E. Maclennan, David M. Walba, Noel A. Clark
Summary: Surface interactions can structurally influence the polarization field of a ferroelectric fluid, allowing for the formation of high polarization states without the need for electric field poling. Different treatments can induce various polarization structures at the surface and within the cell, leading to a range of distinct modes of ferroelectric nematic electro-optic responses.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Nanoscience & Nanotechnology
Man Zhang, Zhe Chen, Yajun Yue, Tao Chen, Zhongna Yan, Qinghui Jiang, Bin Yang, Mirva Eriksson, Jianhua Tang, Dou Zhang, Zhijian Shen, Isaac Abrahams, Haixue Yan
Summary: This study investigated the activity of ferroelectric domain walls in a lead-free Aurivillius phase ferroelectric ceramic using THz-time-domain spectroscopy, and found that the dynamics of domain walls differ at kHz and THz frequencies. The research showed that domain walls have different effects on dielectric permittivity at different frequencies and demonstrated that THz probing can be used to read domain wall dielectric switching.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Materials Science, Multidisciplinary
Marko Dunatov, Andreas Puskaric, Lidija Andros Dubraja
Summary: This study reports a complex salt with exceptional structural flexibility, which undergoes crystal transformations triggered by changes in humidity and temperature. These transformations result in significant changes in the electrical and optical properties of the material.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Physics, Applied
Yue Liu, Kailin Ren, Kaiyang Zeng
Summary: This article discusses the complexity of the contact resonance frequency (f(0)) signal in piezoresponse force spectroscopy, as well as the physical significance and influencing factors of this signal variation, and proposes directions for improving relevant models and mechanisms.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Chemistry, Physical
Kelum Perera, Rony Saha, Pawan Nepal, Rohan Dharmarathna, Md Sakhawat Hossain, Md Mostafa, Alex Adaka, Ronan Waroquet, Robert J. Twieg, Antal Jakli
Summary: The experimental results and theoretical considerations of novel electromechanical effects of ferroelectric nematic liquid crystal droplets coexisting with the isotropic melt are presented in this study. It is found that the droplets have flat pancake-like shapes thinner than the sample thickness. A wing-shaped defect with low birefringence is present in the center of the droplets, moving perpendicular to a weak electric field, and dividing into two at higher fields. The entire droplet drifts along the electric field with a speed independent of droplet size and proportional to the electric field amplitude.
Article
Multidisciplinary Sciences
Raouf Barboza, Stefano Marni, Fabrizio Ciciulla, Farooq Ali Mir, Giovanni Nava, Federico Caimi, Annamaria Zaltron, Noel A. Clark, Tommaso Bellini, Liana Lucchetti
Summary: In this study, we investigated the electrostatic behavior of ferroelectric liquid droplets on a lithium niobate ferroelectric crystal substrate. The droplets exhibit explosive emission of fluid jets upon entering the ferroelectric phase, mostly at the interface, which eventually form secondary droplets.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Chemistry, Physical
Amid Ranjkesh, Neda Ebrahimpour, Mohammad Sadegh Zakerhamidi, Seyed Masoud Seyedahmadian
Summary: In this study, the temperature-dependent dielectric constants and dielectric anisotropy of tungsten oxide nanoparticles doped into a nematic liquid crystal were investigated. The shape and concentration of the nanoparticles were found to significantly impact the temperature-dependent dielectric properties in the nanoparticle-nematic liquid crystal systems.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Chemistry, Multidisciplinary
Hao Pan, Zishen Tian, Megha Acharya, Xiaoxi Huang, Pravin Kavle, Hongrui Zhang, Liyan Wu, Dongfang Chen, John Carroll, Robert Scales, Cedric J. G. Meyers, Kathleen Coleman, Brendan Hanrahan, Jonathan E. E. Spanier, Lane W. W. Martin
Summary: It is demonstrated that the polarization switching behavior of antiferroelectrics can be strongly influenced and effectively regulated by point defects. In the case of PbZrO3 films, the decrease in oxygen pressure during deposition leads to unexpected ferroelectric-like polarization switching, attributed to the creation of bombardment-induced point-defect complexes. These complexes pin the antiferroelectric-ferroelectric phase boundaries and delay the phase transition under changing field. By controlling the concentration of defect complexes, the dielectric tunability of PbZrO3 can be adjusted, including the conversion of positive and negative tunability near zero field.
ADVANCED MATERIALS
(2023)
Article
Multidisciplinary Sciences
Prabesh Gyawali, Rony Saha, Gregory P. Smith, Miroslaw Salamonczyk, Prakash Kharel, Soumitra Basu, Ruipeng Li, Masafumi Fukuto, James T. Gleeson, Noel A. Clark, Antal Jakli, Hamza Balci, Samuel Sprunt
Summary: The study investigates the nature and temperature dependence of smectic ordering in concentrated solutions of various gapped DNA constructs, revealing distinct bilayer and monolayer structures for DNA concentrations in the range of 230 to 280 mg/mL. The bilayer structure appears for gap lengths over 10 bases and transitions into the cholesteric phase at temperatures between 30 to 35 degrees C, while the monolayer structure is predominant for gap lengths less than or equal to 10 bases and remains stable up to temperatures exceeding 40 degrees C. Models for the two layer structures and mechanisms for their stability are discussed in detail.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Multidisciplinary Sciences
Xi Chen, Eva Korblova, Matthew A. Glaser, Joseph E. Maclennan, David M. Walba, Noel A. Clark
Summary: Surface interactions can structurally influence the polarization field of a ferroelectric fluid, allowing for the formation of high polarization states without the need for electric field poling. Different treatments can induce various polarization structures at the surface and within the cell, leading to a range of distinct modes of ferroelectric nematic electro-optic responses.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Chemistry, Multidisciplinary
Zhuojun Meng, Qing Liu, Yi Zhang, Jing Sun, Chenjing Yang, Hongyan Li, Mark Loznik, Robert Gostl, Dong Chen, Fan Wang, Noel A. Clark, Hongjie Zhang, Andreas Herrmann, Kai Liu
Summary: The study introduces a DNA organogel that gels through supramolecular interactions, showing exceptional mechanical properties and biocompatibility, with complete self-healing within 3 seconds. These liquid crystalline organogels exhibit impressive ultimate tensile strengths, stiffness, and toughness, making them potential candidates for a wide range of smart material and biomedical applications.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Jan Thoen, Eva Korblova, David M. Walba, Noel A. Clark, Christ Glorieux
Summary: In high-resolution adiabatic scanning calorimetry (ASC) experiments, the temperature dependencies of enthalpy and specific heat capacity are simultaneously obtained to study phase transitions. The study on the N-N-F transition in RM734 liquid crystal molecule reveals weakly first order transition and critical behavior differences between the high-temperature N phase and low-temperature N-F phase, suggesting larger critical fluctuations in the N-F phase.
Article
Multidisciplinary Sciences
P. Dolganov, N. S. Shuravin, V. K. Dolganov, E. Kats, R. Stannarius, K. Harth, T. Trittel, C. S. Park, J. E. Maclennan
Summary: Through observations under microgravity conditions on the International Space Station, we found that isotropic droplets dispersed over a spherical smectic bubble can form two-dimensional hexagonal structures with spatial and temporal periodicity. The quantitative analysis of the hexagonal structure revealed a peculiar periodic-in-time ordering of the droplets, related to one-dimensional motion with non-uniform velocity.
SCIENTIFIC REPORTS
(2021)
Article
Chemistry, Multidisciplinary
Xi Chen, Zhecong Zhu, Mitchell J. Magrini, Eva Korblova, Cheol S. Park, Matthew A. Glaser, Joseph E. Maclennan, David M. Walba, Noel A. Clark
Summary: An experimental investigation of binary mixtures of organic mesogens RM734 and DIO reveals paraelectric and ferroelectric nematic phases. These mixtures exhibit complete miscibility and ideal mixing properties in terms of phase behavior and polarization density. The similarity in molecular shape, net longitudinal dipole moment, and the tendency for head-to-tail molecular association contribute to this behavior. The significant difference in molecular structures leads to poor solubility in crystal phases but enhances the stability of the ferroelectric nematic phase in the mixtures.
Article
Mechanics
Eric Hedlund, Keith Hedlund, Adam Green, Ravin Chowdhury, Cheol S. Park, Joseph E. Maclennan, Noel A. Clark
Summary: Machine learning techniques have been used to identify inclusions on the surface of liquid crystal films. This method achieves higher accuracy than conventional tracking software, especially in non-uniform backgrounds or when target features are close to each other.
Article
Multidisciplinary Sciences
Xi Chen, Vikina Martinez, Pierre Nacke, Eva Korblova, Atsutaka Manabe, Melanie Klasen-Memmer, Guillaume Freychet, Mikhail Zhernenkov, Matthew A. Glaser, Leo Radzihovsky, Joseph E. Maclennan, David M. Walba, Matthias Bremer, Frank Giesselmann, Noel A. Clark
Summary: The observation of smectic AF phase in liquid crystals, which is characterized by polar, rod-shaped molecules forming layered structures and exhibiting ferroelectric properties, is reported. Two different phase sequences have been observed in binary mixtures of partially fluorinated mesogens.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Multidisciplinary Sciences
Xi Chen, Vikina Martinez, Eva Korblova, Guillaume Freychet, Mikhail Zhernenkov, Matthew A. Glaser, Cheng Wang, Chenhui Zhu, Leo Radzihovsky, Joseph E. Maclennan, David M. Walba, Noel A. Clark
Summary: This study structurally characterized an intermediate phase of liquid crystal, revealing an antiferroelectric smectic phase that fills a gap in the classification of liquid crystals. The key features of the phase sequence were described using a Landau free energy.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Physics, Fluids & Plasmas
Ravin A. Chowdhury, Adam A. S. Green, Cheol S. Park, Joseph E. Maclennan, Noel A. Clark
Summary: High-speed polarized light video microscopy captured the rapid coarsening of the film texture by the mutual annihilation of defects in a smectic-C liquid crystal. The defect locations were determined using an object-detection convolutional neural network, and their topological signs were evaluated using a customized binary classification network.
Article
Physics, Multidisciplinary
Zoom H. Nguyen, K. Harth, A. M. Goldfain, C. S. Park, J. E. Maclennan, M. A. Glaser, N. A. Clark
Summary: Using smectic liquid crystal films as a model system, the coalescence of fluid islands in two dimensions was studied, revealing dynamics that differ from classical models. The process is influenced by factors such as line tension, edge dislocations, viscous dissipation, and background film properties.
PHYSICAL REVIEW RESEARCH
(2021)
Article
Chemistry, Physical
Federico Caimi, Giovanni Nava, Raouf Barboza, Noel A. Clark, Eva Korblova, David M. Walba, Tommaso Bellini, Liana Lucchetti
Summary: The article investigates the surface alignment of the ferroelectric nematic phase and finds specific behaviors and factors that affect the alignment, such as orientation, defects, and electric field response.
Article
Chemistry, Physical
Kanghyeon Koo, Shankar Lalitha Sridhar, Noel Clark, Franck Vernerey, Loren Hough
Summary: The study demonstrates the feasibility of actively driving key biological functions by balancing binding and displacement, such as bacterial movement or selective active filtering in cells. Binding transiently to a flexible medium can overcome stickiness and enable motion. Additionally, in a dynamic system, analogous binding-mediated motion can be actively driven.