Article
Mechanics
Gaojin Li
Summary: This study investigates the self-propulsion behavior of chemically active droplets in a surfactant solution. It shows that the motion of the droplets is controlled by the nonlinear coupling among chemical transport, surfactant consumption, and fluid flow. The study analyzes the parameters that determine the swimming motion of the droplets and finds that the droplets undergo a supercritical bifurcation near the instability threshold. In the highly nonlinear regime, the droplets exhibit a transition from steady translation to unsteady motion with zigzag trajectories.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Multidisciplinary Sciences
Sunghwan Jung
Summary: In this study, a unified fluid potential model is applied to explain the behaviors of animals swimming, flying, and diving in water. By studying impact force and thrust force, it reveals the influence of animal weight on these forces, as well as the balance between swimming speed and thrust force with drag.
SCIENTIFIC REPORTS
(2021)
Article
Mechanics
Bohan Wang, Weiquan Jiang, Guoqian Chen
Summary: In this study, we investigate the bidirectional coupling effect between gravity-driven flow and microorganism concentration by solving the Smoluchowski equation and the Navier-Stokes equation simultaneously. The results show that this coupling effect significantly enhances the velocity and concentration of microorganisms in the central region, as well as the drift velocity and dispersivity. However, in upwelling flows, the dominant influence of the no-slip boundary condition imposed at the wall limits the coupling effect between gravity-driven flow and microorganism concentration.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
Yaming Wei, Jianfeng Zou, Chenglin Zhou, Feng Li, Ziting Zhao
Summary: In this study, the mixing process of two sessile micro-droplets in open electrowetting-on-dielectric digital microfluidics was numerically investigated. It was found that the merging process breaks the symmetry of the droplets and has an impact on the subsequent oscillation, and the enhancement of oscillation-based mixing of the droplets was numerically verified.
Article
Multidisciplinary Sciences
Carlos Acuna, Alfonso Mier Y. Teran, Maria Olga Kokornaczyk, Stephan Baumgartner, Mario Castelan
Summary: This study introduces a deep learning-based methodology for analyzing the self-assembled fractal-like structures formed in evaporated droplets. Experimental results show significant differences in the fractal characteristics of patterns obtained from different mixing procedures of plant extracts, with laminar flow patterns exhibiting the highest fractal structure and turbulent mixture patterns showing the lowest fractality. This approach allows for a more detailed description and differentiation of patterns formed through various mixing procedures at the pure image level.
SCIENTIFIC REPORTS
(2022)
Article
Robotics
Xin Zhou, Xiangyong Wen, Zhepei Wang, Yuman Gao, Haojia Li, Qianhao Wang, Tiankai Yang, Haojian Lu, Yanjun Cao, Chao Xu, Fei Gao
Summary: In this research, we developed a miniature swarm platform with autonomous planner and onboard perception, localization, and control functions, enabling swarm navigation and coordination in dense forests and other complex environments. The planner meets various task requirements, can work in a timely and accurate manner based on limited information, and obtains high-quality trajectories through spatial-temporal joint optimization.
Article
Mechanics
Hongyu Zhao, Daniel Orejon, Khellil Sefiane, Martin E. R. Shanahan
Summary: This study investigates the spontaneous motion of liquid droplets on hydrophobic, micro-structured, solid surfaces with a structural gradient. The research explains the observations by considering variable droplet-surface interactions and incorporates the oscillatory motion of the droplet into the modeling. The results show good agreement between the theoretical model and experiments, highlighting the importance of vertical oscillation in overcoming wetting hysteresis and actuating motion.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Francisco J. Blanco-Rodriguez, J. M. Gordillo
Summary: The study presents a unified theoretical description of liquid jet expulsion, predicting jet speeds through algebraic equations that are in good agreement with experimental and simulation results.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Multidisciplinary Sciences
Maxime Hubert, Stephane Perrard, Nicolas Vandewalle, Matthieu Labousse
Summary: Information storage is crucial for autonomous, out-of-equilibrium dynamics, but synthetic active matter often lacks internal memory implementation. The study reveals that the wave field propelling particles acts as a memory repository, and an excess of memory results in memory-less particle dynamics.
NATURE COMMUNICATIONS
(2022)
Article
Mechanics
Endre Joachim Mossige, Vineeth Chandran Suja, Daniel J. Walls, Gerald G. Fuller
Summary: The study focuses on experimental investigation of droplets rising through viscous liquid, observing that droplets change shape from prolate to oblate spheroids as they mix with the ambient liquid, with their volume increasing and velocity decreasing according to power laws. The scaling relations explain the observed phenomena, but further investigation is needed on the power laws governing the rate of volumetric increase and velocity decrease.
Article
Mechanics
Hao Chen, Qiaoru An, Hongya Zhang, Chengshuai Li, Haisheng Fang, Zhouping Yin
Summary: The presence of surrounding droplets in an ordered array leads to a decrease in the evaporation rate of an evaporating droplet, resulting in a significant increase in its lifetime. These findings enhance our understanding of interactions between droplets in arrays and provide new strategies for controlling droplet evaporation.
Article
Biotechnology & Applied Microbiology
Mahdi Hamidi Rad, Vincent Gremeaux, Farzin Dadashi, Kamiar Aminian
Summary: Inertial measurement units (IMU) have been proven effective for swimming analysis, and a new macro-micro analysis approach is comprehensive in evaluating swimmers' performance during training sessions, showing high efficiency in detecting main events and phases.
FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
(2021)
Article
Mechanics
Khaled H. A. Al-Ghaithi, Oliver G. Harlen, Nikil Kapur, Mark C. T. Wilson
Summary: As inkjet technology advances to produce smaller droplets, the study explores the deposition of micro-droplets onto scratches of commensurate size, identifying seven equilibrium morphologies influenced by inertial spreading, contact-line pinning, imbibition, and capillary flow. Theoretical estimates align with numerical results from a three-dimensional multiphase lattice Boltzmann model, with discussions on the impacts of Reynolds number, Weber number, and contact angles for printing applications. Negative and positive implications for printing are discussed and illustrated through multiple-droplet simulations.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Mohammad Khavari, Tuan Tran
Summary: The study reveals that during the impact of a liquid droplet on a heated surface, bubble nucleation reduces the contact area between the liquid and the solid surface, while fingering patterns contribute to an increase in the total length of the contact line surrounding the contact area.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
R. T. Cerbus, H. Chraibi, M. Tondusson, S. Petit, D. Soto, R. Devillard, J. P. Delville, H. Kellay
Summary: The generation of liquid jets and drops near a liquid-air interface using femtosecond laser pulses involves the nucleation of cavitation bubbles and the emergence of two distinct jets. The first jet is thin and fast, produced during the initial expansion of the bubble, while the second jet is thick and slow, emanating from the surface as the bubble deflates. The mechanism behind this phenomenon has been investigated using experiments and simulations, revealing that the second jet is not a result of bubble expansion but originates from the secondary flows induced by the bubble dynamics. A phase diagram has been established to understand the emergence of the second jet by linking its properties to the control parameters of the problem.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Xiaoxu Zhong, Arezoo M. M. Ardekani
Summary: This paper presents a model for bubble dynamics in a protein solution, including varying surface tension and dynamic adsorption/desorption of protein onto the bubble surface. The study highlights the importance of surface rheology on protein-coated bubble dynamics, with potential applications in drug delivery and ultrasound contrast agents.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Physics, Multidisciplinary
Manish Kumar, Arezoo M. Ardekani
Summary: Viscoelastic flow through porous media is vital in various industrial applications and biological processes. This study investigates the impact of geometrical asymmetry on pore-scale viscoelastic instability, revealing that the asymmetry induces asymmetric flow around two cylinders and the formation of an eddy between them.
EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS
(2023)
Article
Engineering, Biomedical
Mario de Lucio, Yu Leng, Atharva Hans, Ilias Bilionis, Melissa Brindise, Arezoo M. Ardekani, Pavlos P. Vlachos, Hector Gomez
Summary: Subcutaneous injection of therapeutic monoclonal antibodies (mAbs) is a rapidly growing field in the pharmaceutical industry. This study presents a large-deformation poroelastic model to understand high-dose, high-speed subcutaneous injection. The anisotropy of subcutaneous tissue and the multi-layer structure of the skin tissue are considered. The impact of handheld autoinjectors on injection dynamics for different patient forces is analyzed. The simulations highlight the importance of the large deformation approach in modeling large injection volumes and provide insights into the mechanics and transport processes in subcutaneous injections of mAbs.
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
(2023)
Article
Mechanics
Monsurul Khan, Rishabh V. More, Arezoo M. Ardekani
Summary: We propose a constitutive model to predict the viscosity of fiber suspensions, which undergoes shear thinning, at various volume fractions, aspect ratios, and shear stresses/rates. The model is calibrated using data from direct numerical simulation and accurately predicts experimental measurements. The model quantitatively reproduces the experimentally observed shear thinning by using a friction coefficient decreasing with the normal load between the fibers. The findings of this study can be used to design suspension rheology in various applications by tuning the fiber size and volume fraction.
Article
Chemistry, Physical
Ria D. D. Corder, Yuan-Jung Chen, Pattiya Pibulchinda, Jeffrey P. P. Youngblood, Arezoo M. M. Ardekani, Kendra A. A. Erk
Summary: Concentrated suspensions of particles at high volume fractions often exhibit complex rheological behavior, transitioning from shear thinning to shear thickening. Adding non-adsorbing polymers can improve the printability of these suspensions. In this study, we investigated the rheology of concentrated alumina particle suspensions and the effects of adding non-adsorbing polyvinylpyrrolidone (PVP). We found that increasing the concentration of alumina particles and PVP increased the viscosity and yield stress, and the presence of PVP also increased the stress needed to induce shear thickening.
Article
Chemistry, Multidisciplinary
Patrick A. Giolando, Kelsey Hopkins, Barrett F. Davis, Nicole Vike, Adib Ahmadzadegan, Arezoo M. Ardekani, Pavlos P. Vlachos, Joseph V. Rispoli, Luis Solorio, Tamara L. Kinzer-Ursem
Summary: Implantable, bioresorbable drug delivery systems provide a patient-tailored drug dosage with increased patient compliance. Mechanistic mathematical modeling accelerates the design of release systems by predicting physical anomalies and short- and long-term drug release profiles. This study investigates the impact of various parameters on drug release and offers new insight into the design process for tailored release systems.
ADVANCED MATERIALS
(2023)
Article
Pharmacology & Pharmacy
Xiaoxu Zhong, Jean-Christophe Veilleux, Galen Huaiqiu Shi, David S. Collins, Pavlos Vlachos, Arezoo M. Ardekani
Summary: In recent years, significant progress has been made in the studies of spring-driven autoinjectors, leading to an improved understanding of its interactions with tissue and therapeutic proteins. Simulation tools have enhanced the prediction of performance, while this paper addresses critical hydrodynamic considerations and presents a framework for optimizing design. This work is valuable to the pharmaceutic industry as it provides insights into device development and improving patient outcomes.
INTERNATIONAL JOURNAL OF PHARMACEUTICS
(2023)
Article
Mechanics
Adib Ahmadzadegan, Harsa Mitra, Pavlos P. Vlachos, Arezoo M. Ardekani
Summary: We propose a novel method called particle image rheometry (PIR) to measure the rheological properties of fluids using the Brownian motion of suspended particles. PIR estimates the particle ensemble mean square displacement (MSD) from the temporal evolution of the displacement probability density function (PDF). Our evaluations show that PIR achieves a lower error than existing methods, with less than 1% error in passive microrheology measurements.
JOURNAL OF RHEOLOGY
(2023)
Article
Engineering, Biomedical
Vivek Sree, Xiaoxu Zhong, Ilias Bilionis, Arezoo Ardekani, Adrian Buganza Tepole
Summary: Autoinjectors are an important drug delivery option for subcutaneous space. However, current designs do not consider the coupling between autoinjector dynamics and tissue biomechanics. This study presents a Bayesian framework that can optimize autoinjector devices, taking into account the coupled autoinjector-tissue biomechanics and uncertainty in tissue mechanical behavior.
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
(2023)
Article
Physics, Fluids & Plasmas
Monsurul Khan, Rishabh V. More, Arash Alizad Banaei, Luca Brandt, Arezoo M. Ardekani
Summary: In this study, we investigated the rheology of concentrated suspensions under steady shear flow, focusing on the effects of fiber aspect ratio, roughness, flexibility, and volume fraction. By using direct numerical simulations and modeling the fibers as slender bodies in an incompressible Newtonian fluid, we accurately predicted shear thinning behavior and observed an increase in suspension viscosity with increasing parameters such as volume fraction, roughness, fiber rigidity, and aspect ratio. We also observed differences in normal stresses and proposed a modified law to quantify the reduction in jamming volume fraction.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Biology
Chenji Li, Xiaoxu Zhong, Arezoo M. Ardekani
Summary: In this paper, a model is proposed to analyze the factors affecting lymphatic uptake, including interstitial pressure, downstream pressure, and tissue deformation. The results indicate that lymphatic uptake increases with the amplitude of oscillating downstream pressure and the cross-sectional area of initial lymphatics increases with the volumetric strain of the tissue. Intersection angles and positions of two initial lymphatics have minor impacts on lymphatic uptake. However, the lymphatic uptake per unit length of initial lymphatics decreases with their total length.
COMPUTERS IN BIOLOGY AND MEDICINE
(2023)
Article
Optics
Andres Barrio-Zhang, Arezoo M. Ardekani
Summary: This paper presents a novel technique for retrieving particle properties using digital holography microscopy. The technique involves reconstructing synthetic holograms and fitting a Gaussian function to estimate size and sub-pixel position. The method shows good accuracy and reliability in estimating particle refractive index and can be combined with function-fitting approaches to improve accuracy. The technique can have broad applications in nanoparticle characterization.
OPTICS AND LASERS IN ENGINEERING
(2023)
Article
Physics, Fluids & Plasmas
Monsurul Khan, Rishabh V. More, Luca Brandt, Arezoo M. Ardekani
Summary: We explain the origins of yield stress, shear thinning, and normal stress differences in rigid fiber suspensions. We investigate the interplay between the hydrodynamic, noncontact attractive and repulsive, and interfiber contact interactions. The shear-thinning viscosity and finite yield stress obtained from the Immerse Boundary Method simulations are in quantitative agreement with experiential results from the literature.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Chemistry, Physical
Manish Kumar, Derek M. Walkama, Arezoo M. Ardekani, Jeffrey S. Guasto
Summary: This study investigates the role of viscoelastic instability in fluid flow through porous media at high Peclet numbers. The results show that viscoelastic instability enhances transverse dispersion in ordered media, while preferential flow paths enhance longitudinal dispersion.
Article
Chemistry, Physical
Manish Kumar, Derek M. Walkama, Arezoo M. Ardekani, Jeffrey S. Guasto
Summary: In this study, we investigated the mechanical dispersion of viscoelastic fluid flow through porous media. Our findings from microfluidic experiments and numerical simulations demonstrate that viscoelastic instability enhances dispersion transverse to the mean flow direction. Additionally, we observed that preferential flow paths can affect the instability and transport processes.