Article
Mechanics
Lingqi Zhao, Xin Zhong, Huicheng Feng
Summary: This paper experimentally observed that chaotic induced-charge electro-osmosis (ICEO) is stable in weak electric fields and becomes chaotic in strong electric fields. The observed chaotic ICEO flow is irregular and unstable across the whole velocity field, and the chaos degree grows with increasing electric field.
Article
Chemistry, Physical
Hideyuki Sugioka, Hiroki Yoshijima
Summary: In this study, it was found that artificial cilia made up of three beams with different lengths arranged in parallel can exhibit metachronal motion through induced charge electro-osmosis (ICEO) induced by AC electric fields. The recovery of the ICEO cilia's beams upon suddenly turning off the electric fields was also observed to be almost simultaneous. These findings, discussed using a mathematical model, are valuable for designing ICEO cilia and advancing innovative microfluidic applications in the future.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Chemistry, Physical
Hideyuki Sugioka, Taiki Kado, Hiroya Nakamura
Summary: The study found that conductive carbon mesh made through induced charge electro-osmosis under DC electric fields shows great stretchability, with potential applications as a stretchable actuator under AC electric fields. This finding has important implications for future microfluidic circuits.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Chemistry, Physical
Ruixing Yu, Bowen Ji, Lingqi Zhao, Xin Zhong, Huicheng Feng
Summary: In this study, the phenomenon of induced-charge electro-osmosis (ICEO) in cetyl-trimethylammonium bromide (CTAB) solutions was found to take several seconds to fully develop after the application of an electric field, contrary to previous research. A phenomenological model for ICEO of CTAB solutions was proposed, explaining the slow development as a result of the thixotropic behavior of CTAB solutions. Additionally, variations in ICEO velocity were observed with changes in CTAB concentration, viscosity, electrical conductivity, and electric field frequency.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2023)
Article
Chemistry, Physical
Hideyuki Sugioka, Hiroya Nakamura
Summary: Controlling the self-organizing structure is crucial for the application of self-organizing materials. In this study, a weaving method of carbon fibers using induced-charge electro-osmosis (ICEO) was reported. The researchers demonstrated that low-density carbon fibers with a dendritic structure can be grown by applying a DC voltage, and shrink irreversibly when an AC voltage is applied, leading to the formation of a weaving structure. The mechanism of the DC-AC weaving phenomenon related to dielectrophoresis and ICEO phenomena was clarified through visualization. This technology offers a different design strategy to improve the structure of self-organizing materials for microfluidic circuits.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2022)
Article
Chemistry, Physical
Huicheng Feng, Lingqi Zhao, Xin Zhong, Xingfeng Lei, Teck Neng Wong
Summary: The study found that induced-charge electro-osmosis velocity initially increases and then decreases with increasing sodium chloride concentration, with the peak velocity concentration varying with electric field strength. As electric field frequency increases, ICEO velocity reaches a maximum, with the frequency of peak velocity determined by microfluidic chip geometry and ion concentration. Additionally, inflowoutflow asymmetry and vortex positions were observed in ICEO, showing a dependence on electric field and NaCl concentration.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Chemistry, Multidisciplinary
Riccardo Zamboni, Carlos Sebastian-Vicente, Cornelia Denz, Joerg Imbrock
Summary: This study presents an electro-coalescence method for microfluidic droplet surfactant-stabilized emulsion based on light-induced virtual electrodes. By adjusting the exposure time, droplet pairs can be selectively coalesced or the entire emulsion can be dispersed.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Physical
Hideyuki Sugioka, Koshi Ueno
Summary: This study presents an integrated fluidic circuit composed of a ratchet-type pump and an elastic valve using induced charge electro-osmosis (ICEO), demonstrating the opening and closing functions of the valve. Experimental results show that the system can generate a net circular flow in microfluidics and close it within a short period of time. The prototype ICEO system is believed to have significant potential in the field of microfluidics.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Chemistry, Physical
Hideyuki Sugioka, Koshi Ueno
Summary: This study reports an electrically actuated cilium that exhibits an asymmetrical motion due to induced charge electro-osmosis (ICEO), which has important applications in innovative biomedical microfluidic systems.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2022)
Article
Environmental Sciences
Suiqiao Yang, Hu Zhang, Yang Hu, Huijun Jin, Jintao Hu, Hongchun Li, Ming Lu
Summary: This study investigated the influence of freeze-thaw on the electroosmotic removal of petroleum and found that the combination of freeze-thaw and electroosmosis significantly improved the efficiency of petroleum remediation in contaminated soil.
ENVIRONMENTAL POLLUTION
(2023)
Article
Engineering, Environmental
Wei Ren, Qiming Zhang, Cheng Cheng, Fei Miao, Hui Zhang, Xubiao Luo, Shaobin Wang, Xiaoguang Duan
Summary: In this study, a 3D electrochemical system was established by coupling conventional graphite electrodes with dispersed carbon nanotubes (CNTs) to enhance the electrochemical activation of peroxydisulfate (PDS). This led to efficient oxidation of pollutants and maintenance of electrode cleanliness and activity for long-term operation.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Physics, Multidisciplinary
Evgeniy Boyko, Vesna Bacheva, Michael Eigenbrod, Federico Paratore, Amir D. Gat, Steffen Hardt, Moran Bercovici
Summary: By injecting momentum in a region surrounding an object in microscale flow, both cloaking and shielding conditions can be achieved, with the ability to dynamically switch between different states demonstrated both theoretically and experimentally.
PHYSICAL REVIEW LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Jiahao Yang, Xinchen Kang, Jiapeng Jiao, Xueqing Xing, Yaoyu Yin, Shuaiqiang Jia, Mengen Chu, Shitao Han, Wei Xia, Haihong Wu, Mingyuan He, Buxing Han
Summary: Using a ternary ionic-liquid-based electrolyte, this study couples bulk metal electrodes to achieve highly efficient electro-reduction of CO2 to CO. The ternary electrolyte increases current density and suppresses the hydrogen evolution reaction, while maintaining a high Faradaic efficiency. The aggregation behavior of the electrolyte and the arrangement of different chain lengths of ionic liquid cations contribute to the improved wettability, CO2 adsorption, and diffusion channel for H+, resulting in high current density and FECO values.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Jihye Park, Jun Hyeong Gu, Myeong Ju Lee, Sun Hwa Park, Junghoon Jahng, Donghwa Lee, Young-Gi Lee, Hosun Shin, Jung-Yong Lee, Jae Yong Song
Summary: Organic electrodes are potential candidates for future rechargeable lithium-ion batteries (LIBs) due to their natural abundance and lightweight. However, they suffer from low electrochemical capacity, low capacity retention, and elution of active electrode materials. In this study, the researchers developed a field-induced charge-transfer route and nanostructuring to improve the electrochemical performance of organic electrodes.
ENERGY STORAGE MATERIALS
(2023)
Article
Physics, Fluids & Plasmas
T. Lafleur
Summary: It has been found that there are important similarity parameters between particle extraction systems using hybrid AC/DC biasing and conventional DC biased systems. The onset of particle reflection depends on the AC frequency, voltage magnitude, and initial particle injection velocity. When the injection current exceeds the AC limit, the system becomes unstable and generates self-excited space-charge oscillations.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2021)
Article
Biochemical Research Methods
Corliss K. Sio, Tashi Parsons-Davis, Elaine Lee, Josh Wimpenny, Andrew J. Pascall, Joshua D. Kuntz, John J. Goodell, Kevin E. Roberts, Bryan B. Bandong, Neil R. Bennett
RAPID COMMUNICATIONS IN MASS SPECTROMETRY
(2020)
Article
Mechanics
Harishankar Manikantan, Todd M. Squires
JOURNAL OF FLUID MECHANICS
(2020)
Article
Materials Science, Multidisciplinary
Scott C. Bukosky, Joshua A. Hammons, Brian Giera, Elaine Lee, Jinkyu Han, Megan C. Freyman, Anna Ivanovskaya, Kerry G. Krauter, Joshua D. Kuntz, Marcus A. Worsley, T. Yong-Jin Han, William D. Ristenpart, Andrew J. Pascall
PHYSICAL REVIEW MATERIALS
(2020)
Article
Chemistry, Physical
Alexandra Bayles, Julia M. Fisher, Connor S. Valentine, Arash Nowbahar, Matthew E. Helgeson, Todd M. Squires
Summary: Polymeric ionogels are helpful for the release and storage of molecular solutes in various applications. A study showed that water diffuses through these ionogels by hopping between relatively immobile cations, and the activation energy barrier can be determined from H-1 NMR chemical shift measurements to predict water's diffusivity quantitatively. This predictive model could accelerate IL-material screening and suggest targets for rational design based on the strong connection between solute mobility and hydrogen bonding.
JOURNAL OF PHYSICAL CHEMISTRY B
(2021)
Article
Multidisciplinary Sciences
Huanshu Tan, Anirudha Banerjee, Nan Shi, Xiaoyu Tang, Amr Abdel-Fattah, Todd M. Squires
Summary: The study proposes a two-step strategy to deliver suspended colloids to hidden targets in closed porous media by converting hidden targets into soluto-inertial beacons and introducing deliverable objects designed to autonomously migrate against solute fluxes emitted by the targets. Experimental and theoretical demonstrations show the design elements required for delivering colloidal objects to hidden targets in various environments and technologies.
Article
Physics, Applied
T. Chang, S. Mukherjee, N. N. Watkins, E. Benavidez, A. M. Gilmore, A. J. Pascall, D. M. Stobbe
Summary: This article presents a new millimeter-wave electromagnetic monitoring approach for liquid metal droplet-on-demand printing to support high-speed and real-time evaluation. The method can detect trends at both macro-level (print variation and anomalies) and micro-level (droplet size, position, and dynamics), demonstrating its potential for long-term monitoring and feedback control in printing processes.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Joseph M. Barakat, Todd M. Squires
Summary: This study investigates the behavior of elastic inclusions embedded in curved fluid interfaces. The results show that the behavior of the inclusions depends on their size and stiffness. Small, stiff inclusions are limited by bending, while larger and softer inclusions are limited by stretching.
Letter
Mechanics
Nicholas N. Watkins, Eric S. Elton, Phillip H. Paul, Victor A. Beck, Jason R. Jeffries, Andrew J. Pascall
Summary: Experiments demonstrate that stable liquid metal droplets can be generated in the high Z regime, indicating the need for additional physics to understand droplet-on-demand technology.
Article
Multidisciplinary Sciences
Varun H. Hegde, Michael F. Doherty, Todd M. Squires
Summary: The article introduces two models to describe solvent transport through swollen nonporous membranes, and demonstrates through a fluid-solid model that both models are valid and make identical predictions. The model research provides explanations for reverse osmosis measurements and a basis for high-pressure limiting flux phenomena, while also offering a framework for treating mechanically heterogeneous nonporous membrane materials.
Article
Physics, Fluids & Plasmas
Joseph M. Barakat, Todd M. Squires
Summary: The importance of understanding the mechanics of curved, heterogeneous, surfactant-laden surfaces and interfaces in engineering and biological applications is highlighted in this paper. Previous models have mainly focused on homogeneous systems with planar or fixed curvature. The authors investigate a dynamic model involving a two-phase surface fluid on a curved interface, with the aim of understanding how changes in surface curvature affect the flow inside the domain. The results show that the surface curvature relaxes diffusively and that there is a critical surface capillary number above which shape instability occurs.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Chemistry, Multidisciplinary
Junchi Ma, Olivia M. Haider, Chih-Cheng Chang, Kathryn A. Grzesiak, Todd M. Squires, Lynn M. Walker
Summary: The formation of highly stable water-in-oil emulsions poses challenges in upstream and downstream processing. The adsorption of surface-active asphaltenes at the oil/water interface is found to result in the formation of rigid films. The interfacial properties differ under good and poor solvent conditions. This study provides insights into the impact of the aggregation state of asphaltenes on the stability and mechanics at the oil/water interface.
Article
Multidisciplinary Sciences
Omar A. Saleh, Sam Wilken, Todd M. Squires, Tim Liedl
Summary: This study investigates the dynamics of dilute internal inclusions, called vacuoles, within liquid droplets of DNA nanostar particles. The researchers observe appearance, growth, and bursting of the vacuoles, and find that their growth follows a linear relationship with time. The vacuoles burst when they reach the droplet interface, causing droplet motion due to osmotic pressure. A diffusion-based model is developed to explain these behaviors quantitatively.
NATURE COMMUNICATIONS
(2023)
Article
Biochemical Research Methods
Parth R. Shah, Huanshu Tan, David Taylor, Xiaoyu Tang, Nan Shi, Afnan Mashat, Amr Abdel-Fattah, Todd M. Squires
Summary: The temperature dependence of diffusiophoretic mobility (D-DP) has been investigated experimentally and compared with theoretical predictions. A new microfluidic approach has been developed to enable steady state gradients and precise measurements of diffusiophoretic migration. The measured results show that D-DP values increase with temperature and agree with theoretical predictions based on electrophoretically-measured zeta potentials. These findings demonstrate the accuracy of existing diffusiophoresis theories and the potential of the new microfluidic approach.
Article
Chemistry, Physical
Joseph M. Barakat, Todd M. Squires
Summary: This research explores the interaction of inert colloids in curved interfaces, demonstrating that a curvature gradient can induce capillary force on inert colloids. Through 2D Laplace problems, the study explains the factors to consider when calculating particle forces in detail. By clarifying some nuances in capillary statics and electrostatics, the research extends previous findings in the field.
Article
Mechanics
Victor A. Beck, Nicholas N. Watkins, Ava S. Ashby, Aiden A. Martin, Phillip H. Paul, Jason R. Jeffries, Andrew J. Pascall