Article
Energy & Fuels
Zheyu Liu, Maojie Chai, Xin Chen, Seyed Hossein Hejazi, Yiqiang Li
Summary: Experimental investigation of flow regimes in a rectangular micmchannel using a water-oil system revealed four distinct flow regimes based on parameters such as viscosity ratios, velocity ratios, and capillary numbers. An exponential correlation was found between viscosity ratio and velocity ratio in transitioning flow regimes, with different effects on droplet size and slug length.
Article
Engineering, Chemical
Akepogu Venkateshwarlu, Ram Prakash Bharti
Summary: This study investigated the hydrodynamics of droplet generation in two-phase flow through a T-junction cross-flow microfluidic device by examining the influences of capillary number and flow rate ratio. It identified different flow regimes and presented correlations to guide the design of droplet microfluidics devices based on droplet size, detachment time, and generation frequency.
JOURNAL OF THE TAIWAN INSTITUTE OF CHEMICAL ENGINEERS
(2021)
Article
Chemistry, Analytical
Sajad Yazdanparast, Pouya Rezai, Alidad Amirfazli
Summary: A co-flow microfluidic droplet-generation device with flexible walls was developed, allowing for the adjustment of continuous phase channel width to control droplet sizes. Two different droplet-generation regimes were observed at low dispersed phase Weber numbers. Reducing the channel width produced smaller droplets and a wider range of droplet sizes compared to current technology.
Article
Engineering, Chemical
Wei Yu, Bo Li, Xiangdong Liu, Yongping Chen
Summary: A numerical research investigated the generation of triple emulsion droplets in a three-dimensional axisymmetric flow-focusing device. The study identified three flow regimes: dripping, jetting, and threading. The effects of operation conditions, such as flow rate and interfacial tension, on droplet generation were clarified, with viscosity also playing a significant role.
CHEMICAL ENGINEERING SCIENCE
(2021)
Article
Chemistry, Physical
Keshvad Shahrivar, Francesco Del Giudice
Summary: The use of viscoelastic solutions of xanthan gum in microfluidic devices enables controlled single particle encapsulation, with efficiency up to 2-fold higher than predicted by Poisson statistics. By identifying specific xanthan gum concentrations, researchers discovered that single encapsulation efficiency was increased. An empirical formula was introduced to aid in the design of controlled viscoelastic encapsulation systems.
Article
Engineering, Chemical
E. M. Arun Sankar, Mohammad Shahab, Raghunathan Rengaswamy
Summary: This paper proposes a novel technique for sorting drops using a one-dimensional microfluidic network and hydrodynamic interactions. Computational results and genetic algorithm are used to identify inlet spacings that are insensitive to experimental errors and can completely sort a large number of drops. The identified inlet spacing is a one-time process for a given set of drops, ensuring consistent sorting efficacy for different operating flow rates.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2021)
Article
Chemistry, Physical
Dawei Pan, Yingjuan Zhang, Taoxian Zhang, Bo Li
Summary: The generation of polymeric fluid droplets via a microfluidic device with co-flowing structure is systematically clarified by investigating the influences of outer phase flow rate and polystyrene (PS) mass concentration. Results show that satellite droplet diameter increases with PS mass concentration, while the influence of continuous fluid flow rate varies and depends on the PS mass concentration.
COLLOID AND INTERFACE SCIENCE COMMUNICATIONS
(2021)
Review
Biochemical Research Methods
Davood Khoeini, Timothy F. Scott, Adrian Neild
Summary: Research shows that environmental control offered by microfluidic systems can achieve non-equilibrium reaction conditions, leading to complex self-assembled structures. The study demonstrates that kinetically-controlled self-assembly can be achieved through alterations to the immediate microenvironment.
Article
Mechanics
Jinggang Zhang, Xitong Zhang, Wei Zhao, Haihu Liu, Youhua Jiang
Summary: In this study, the generation of surfactant-laden droplets in a T-junction was simulated using a lattice Boltzmann method. The concentration of surfactants was found to affect the droplet generation regime, shifting from squeezing to dripping and then to jetting as the surfactant concentration increases. The influence of surfactants on the upstream pressure and the role of surfactants under different capillary numbers were also investigated. Additionally, phase diagrams were established to describe the variation of the droplet generation regime with flow rate ratio and capillary number in both clean and surfactant-laden systems.
Article
Biochemical Research Methods
Kunpeng Cai, Shruti Mankar, Taiga Ajiri, Kentaro Shirai, Tasuku Yotoriyama
Summary: The study introduces a fully integrated high-throughput microfluidic circulatory fluorescence-activated cell sorting system capable of significantly increasing the purity of rare cells in a short period of time and effectively enriching different types of cells. Through a sequential sorting process and efficient contamination-free design, effective enrichment of clinical rare cells has been achieved.
Article
Engineering, Environmental
Hamid Asadi-Saghandi, Javad Karimi-Sabet, Sohrabali Ghorbanian, Seyed Mohammad Ali Moosavian
Summary: This study examined flow patterns of six liquid-liquid systems in a numbered-up microfluidic set-up, identifying three distinct flow regimes of slug flow, droplet flow, and parallel flow. Flow uniformity was achieved in the scaled-out microfluidic device, and comprehensive dimensionless analysis was conducted to determine suitable combinations of dimensionless numbers for proposing generalized flow pattern maps. Investigation into slug and droplet length and velocity was also carried out.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Analytical
Woohyuk Kim, Beomseok Cha, Jessie S. Jeon, Jinsoo Park
Summary: We have developed an acoustofluidic method for dynamically controlling the chemical concentration (CC) within picoliterscale droplets at high-throughput production. The method involves rapidly mixing two fluids using acoustic streaming flow-induced micro-vortices, and precisely controlling the mixing index through modulation of the wave amplitude. We have demonstrated the applicability of this method for producing droplet libraries with tunable CCs, which is promising for various droplet microfluidic applications.
SENSORS AND ACTUATORS B-CHEMICAL
(2023)
Article
Engineering, Chemical
Ziwei Liu, Xiyang Liu, Shaokun Jiang, Chunying Zhu, Youguang Ma, Taotao Fu
Summary: This study investigated the application of Y step emulsification technology in microfluidic devices, focusing on the influences of microdevice structures and fluid physical properties on droplet generation. Important factors affecting emulsion flux were identified, and a prediction equation for droplet size was proposed based on inertial and viscous forces of the dispersed phase.
CHEMICAL ENGINEERING SCIENCE
(2021)
Article
Physics, Multidisciplinary
Beomseok Cha, Woohyuk Kim, Giseong Yoon, Hyunwoo Jeon, Jinsoo Park
Summary: Digital microfluidics based on sessile droplets is a promising technology for various applications, but faces challenges in sample mixing due to quiescent flow conditions. By utilizing solutal Marangoni flows for droplet mixing, this limitation can be addressed, although it requires a comparably long time for complete mixing.
FRONTIERS IN PHYSICS
(2021)
Article
Engineering, Chemical
S. D. Svetlov, R. Sh Abiev
Summary: The paper describes the results of droplet formation modeling in a microfluidic device based on the force balance method, using Navier-Stokes and continuity equations. The study shows that the continuous phase flow rate significantly influences the hydrodynamic situation, while the dispersed phase viscosity has a stronger impact on the position of flow regimes boundaries.
CHEMICAL ENGINEERING SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Ewa P. Gajewska, Sara Szymkuc, Piotr Dittwald, Michal Startek, Oskar Popik, Jacek Mlynarski, Bartosz A. Grzybowski
Article
Chemistry, Analytical
Natalia Pacocha, Jakub Boguslawski, Michal Horka, Karol Makuch, Kamil Lizewski, Maciej Wojtkowski, Piotr Garstecki
Summary: Droplet microfluidics have revolutionized analytical biology and bacterial research, but the lack of a high-throughput label-free method for detecting bacteria in nanoliter droplets limits their full potential.
ANALYTICAL CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Minju Kim, Miroslaw Dygas, Yaroslav Sobolev, Wiktor Beker, Qiang Zhuang, Tomasz Klucznik, Guillermo Ahumada, Juan Carlos Ahumada, Bartosz A. Grzybowski
Summary: The tethering of organometallic catalysts onto nanoparticles, with the use of gating ligands, allows for control of substrate selectivity and site selectivity. The strategy of self-assembling macromolecular environments on nanoparticles can enhance the selectivity of catalysts, and should be guided by theoretical models.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Priyanka Sharan, Witold Postek, Thomas Gemming, Piotr Garstecki, Juliane Simmchen
Summary: This study systematically investigated the motion of Pt@SiO2 Janus particles at a liquid-liquid interface, finding that the propulsion behavior on both oil-water and solid-water interfaces is quantitatively similar. The motion characteristics are controlled by factors such as reaction product absorption by oil, slip locking by surfactant, and potential Marangoni effect.
Review
Chemistry, Multidisciplinary
Witold Postek, Piotr Garstecki
Summary: Antibiotic-resistant bacteria are a growing concern in various environments, including healthcare. Urgent action is needed to discover new antibiotics, diagnose resistance in infectious pathogens, and understand the distribution of resistance levels in populations and single cells. Droplet microfluidics offers high-throughput screening capabilities, allowing for the search of drug combinations to combat multidrug-resistant bacteria and the exploration of resistance origins. Manipulating aqueous droplets containing antibiotics and bacteria, microfluidic systems can automate the preparation of antibiotic concentration gradients for combinatorial assays.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Review
Nanoscience & Nanotechnology
Bartosz A. Grzybowski, Yaroslav Sobolev, Olgierd Cybulski, Barbara Mikulak-Klucznik
Summary: This Review explores the impacts of centrifugal and shear forces generated by the rotation of liquids or solid materials on small-scale flows, self-organization phenomena, materials synthesis, and chemical reactivity. It discusses various applications, including separations, lab-on-a-disc systems, colloidal crystallization, and the manipulation of living organisms. It also highlights the combined use of centrifugal and shear forces in rotating reactors for accelerating reaction kinetics, modulating chemical reactivity, and enabling complex extractions.
NATURE REVIEWS MATERIALS
(2022)
Article
Chemistry, Analytical
Yu-Ting Kao, Silvia Calabrese, Nadine Borst, Michael Lehnert, Yu-Kai Lai, Franziska Schlenker, Peter Juelg, Roland Zengerle, Piotr Garstecki, Felix von Stetten
Summary: A novel microfluidic one-pot wash-free fluorescence in situ hybridization (FISH) assay was developed for detection and quantification of bacterial load, offering simplicity, speed, and accuracy in analysis. This method is significant for quantitative analysis of bacterial load.
Article
Chemistry, Analytical
Artur Ruszczak, Pawel Jankowski, Shreyas K. Vasantham, Ott Scheler, Piotr Garstecki
Summary: Water-in-oil droplet microfluidics is a promising technology for high-throughput single-cell antimicrobial susceptibility assays and investigation of drug resistance mechanisms. However, the predictable retention of active molecules inside droplets is still a major challenge. In this study, we analyzed 36 descriptors of antibiotic molecules and found that partition coefficient and fractional polar surface area are the key physicochemical properties that predict antibiotic retention. Our findings have implications in designing droplet antibiotic assays and understanding the retention of small molecules in water-in-oil emulsions.
ANALYTICAL CHEMISTRY
(2023)
Article
Biochemical Research Methods
Francesco Nalin, Maria Celeste Tirelli, Piotr Garstecki, Witold Postek, Marco Costantini
Summary: tuna-step is a novel microfluidic module based on step emulsification that allows for reliable generation of droplets of different sizes. By incorporating a tunable nozzle and a new surface modification method, we achieved variation in droplet volume and produced functionally graded soft materials.
Article
Biochemical Research Methods
Natalia Pacocha, Marta Zapotoczna, Karol Makuch, Jakub Boguslawski, Piotr Garstecki
Summary: This study proposes a droplet-based label-free method for quantifying the antibiotic response of the entire population at the single-cell level. By studying samples of two common pathogens, it was found that the profile shape can provide information about the coexistence of bacterial subpopulations, their sizes, and antibiotic heteroresistance. This method can indicate the outcome of antibiotic treatment and identify tolerant subpopulations associated with increased risks for persisting infections.
Review
Biochemical Research Methods
Witold Postek, Natalia Pacocha, Piotr Garstecki
Summary: The rise of antibiotic resistance poses a threat to global health, and microfluidic systems have the potential to be applied in antibiotic susceptibility testing. In this article, we introduce the application of microfluidic systems and discuss the associated challenges, emphasizing the importance of technological advancements in various aspects to slow down the emergence of antibiotic resistance.
Article
Chemistry, Physical
Yu-Kai Lai, Adam S. Opalski, Piotr Garstecki, Ladislav Derzsi, Jan Guzowski
Summary: In this study, a novel double-step emulsification method is demonstrated for the direct generation of multi-core double emulsions, and a predictive model for the number of cores is provided. The presence of cores affects the formation of double-emulsion droplets.
Article
Polymer Science
Dominika Ogonczyk, Pawel Jankowski, Piotr Garstecki
Article
Chemistry, Multidisciplinary
Adam S. Opalski, Karol Makuch, Ladislav Derzsi, Piotr Garstecki
Article
Chemistry, Physical
Karol Makuch, Robert Holyst, Tomasz Kalwarczyk, Piotr Garstecki, John F. Brady