Article
Chemistry, Multidisciplinary
Mario Alberto Saucedo-Espinosa, Maximilian Breitfeld, Petra Stephanie Dittrich
Summary: This study demonstrates the stabilizer-free electrochemical synthesis of gold nanoparticles inside nanoliter-sized reactors. By utilizing the recirculation flows inside confined droplets, the aggregation of nanoparticles after nucleation is prevented. This method allows for fine-tuning of the electrochemical synthesis of gold nanoparticles and can be used for the formation of other metal nanoparticles.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Shaobo Jin, Guoyong Ye, Na Cao, Xuling Liu, Liguo Dai, Pengpeng Wang, Tong Wang, Xueyong Wei
Summary: This study demonstrates a method of surface acoustic wave-controlled fusion of microdroplets, which shows good arrangement effect of different sizes of microdroplets without any modification.
Article
Chemistry, Physical
Carin C. S. Batista, Alessandro Jager, Brunno L. Albuquerque, Ewa Pavlova, Petr Stepanek, Fernando C. Giacomelli
Summary: This study successfully synthesized polymer-stabilized silver nanoparticles (AgNPs) using microfluidic devices, resulting in nanoparticles with improved homogeneity. By adjusting the concentrations of the silver precursor and reducing agent, the size and polydispersity of the nanoparticles can be controlled. The use of the block copolymer PEO-b-P2VP as a stabilizer led to larger nanoparticles compared to those stabilized by PVP.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Engineering, Environmental
Wei -Yi Chu, Yi-Ru Chiou, Ren-Hao Luo, Tzu-Heng Chen, Cheng-Ju Yu, Yi-Ju Chou, Huan-Tsung Chang, Chien-Fu Chen
Summary: This article introduces a new technique for the synthesis of colloidosomes using a microfluidic droplet device and partially miscible liquids. By dissolving liquids within droplets, hydrophilic nanoparticles can be close-packed at the liquid interface to form colloidosomes. This method also enables colloidosomes to be synthesized within a narrow range of sizes. The close-packing of nanoparticles is confirmed by modifying colloidosomes into signal-enhanced lateral flow assays, which demonstrates their potential application in bacterial detection platforms, drug encapsulation, and biosensing.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Physical
Huayi Shi, Bin Song, Runzhi Chen, Qiang Zhang, Guyue Hu, Jing Li, Jinhua Wang, Xinyu Meng, Houyu Wang, Yao He
Summary: The study presents a method for fabricating bimetallic nanoparticles with tunable size and composition on a silicon surface using microfluidic control. By controlling precursor concentration, flow rate, and reaction time, a series of ultrasmall bimetallic nanoparticles with clean surfaces and tight size distributions were successfully synthesized.
Article
Nanoscience & Nanotechnology
Guangyao Cheng, Kuan-Ting Lin, Yinghua Ye, Hang Jiang, To Ngai, Yi-Ping Ho
Summary: This study introduces a novel photo-responsive fluorosurfactant based on fluorinated plasmonic nanoparticles, which has shown effectiveness in stabilizing water-in-fluorocarbon oil droplets. The photothermal response enabled by the fluorinated gold-silica core-shell nanoparticles has potential for droplet movement and alteration of interfacial stability. The unique photo-responsiveness provided by the plasmonic nanoparticles is expected to enhance droplet microfluidics with an active surfactant for reconfigurable optical manipulation.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Biochemical Research Methods
Jatin Panwar, Christoph A. A. Merten
Summary: The crosstalk between fluorescent biomarkers in multispectral fluorescence analysis is reduced using a method that modulates multiple laser beams to selectively excite the fluorophores by a single beam of a specific wavelength. The emission signals are acquired only from the fluorescence channel corresponding to the excitation wavelength in a specific time window. This method greatly reduces crosstalk contribution between channels and allows for the resolution of indistinguishable fluorescence populations in droplet analysis.
Article
Engineering, Electrical & Electronic
Zhigang Yang, Luntao Dong, Meng Wang, Yanhui Jia, Conghui Wang, Peiqing Li, Guojun Liu
Summary: A controllable synthesis method of silver nano-particles (AgNPs) using microfluidics and piezoelectric drive technology is proposed. Experimental results show that the operating parameters of the reactor have an effect on the particle size, concentration, and homogeneity of the synthesized AgNPs. It is also found that adding a reasonable amount of protectant can effectively inhibit particle agglomeration and ensure good homogeneity and monodispersity.
SENSORS AND ACTUATORS A-PHYSICAL
(2022)
Article
Chemistry, Physical
Oksana Velgosova, Livia Macak, Elena Cizmarova, Vladimir Mara
Summary: This study aimed to prepare silver nanoparticles through chemical reduction and analyze the influence of different reduction agents on the reduction rate and shape of the nanoparticles. The results showed that the combination of reduction agents significantly affected the synthesis rate of silver nanoparticles and the color of the solutions, which depended on the shape and size of the nanoparticles.
Article
Chemistry, Multidisciplinary
Gui Bing Hong, Yi Hua Luo, Kai Jen Chuang, Hsiu Yueh Cheng, Kai Chau Chang, Chih Ming Ma
Summary: In this study, silver nanoparticles were successfully prepared using a chemical reduction synthesis method, followed by low-temperature sintering to obtain Ag-conductive ink for flexible substrate application. The size and shape of the AgNPs were well controlled by varying reaction parameters, and the electrical resistivity of the ink was optimized under specific sintering conditions. These findings may have implications for future research on other metals as well.
Article
Materials Science, Multidisciplinary
Zhiqiang Zhu, Tianao Chen, Yuanqing Zhu, Fangsheng Huang, Kai Mu, Ting Si, Ronald X. Xu
Summary: Programmable pulsed aerodynamic printing (PPAP) is a method for patterning soft materials with extensive compatibility and multi-scale and multi-interface properties. PPAP utilizes programmable pulsed airflow to shear pendant droplets at the nozzle orifice, covering a broad range of parameters. Demonstrations of PPAP include cell-loaded annular particles, liquid metal circuits, laser stimuli-responsive microcapsules, calcium alginate elastomers, and 3D multi-interface clusters.
Article
Multidisciplinary Sciences
Ehsan Naderi-Samani, Reza Shoja Razavi, Khanali Nekouee, Hamed Naderi-Samani
Summary: This study synthesized silver nanoparticles using the chemical reduction method and prepared conductive inks. The synthesized nanoparticles were characterized and evaluated using XRD, FE-SEM, TEM, and DLS. The sample with the smallest size of silver nanoparticles was selected as the optimal sample for further research. The conductive ink prepared with the optimal sample showed low surface electrical resistance on PET and ABS substrates.
Article
Chemistry, Inorganic & Nuclear
Jiyan Wei, Xiaoquan Li, Fuping Bian, Jun Zeng, Jiwen Hu, Tongqiang Zong, Na Li, Shudong Lin
Summary: This article introduces a facile method for synthesizing high purity AgNWs using a one-pot polyol method and heterogeneous nucleation mechanism with AgCl suspension as nucleating agents. The resulting high purity silver nanowires with aspect ratio over 1500 are ideal materials for flexible transparent conductive films and will find wide applications in various fields.
INORGANIC CHEMISTRY COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Tiantian Cao, Chenghong Wang, Zijian Zhou, Lei Liu, Shengming Xu, Haitao Song, Wei Lin, Zhenghe Xu
Summary: A novel magnetic multi-functional nanocomposite, MagS-Ag, is developed using a facile route, exhibiting preferable physical and chemical properties and outstanding capabilities in catalytic reduction and elemental capture. Additionally, the material can be easily separated/collected and regenerated after multiple cycles, showing great potential for wide applications.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Huachen Tao, Tianyi Wu, Sina Kheiri, Matteo Aldeghi, Alan Aspuru-Guzik, Eugenia Kumacheva
Summary: The study introduces an autonomous ML-driven, oscillatory MF platform for the synthesis of inorganic nanoparticles (NPs), which accelerates the identification and optimization of reaction conditions. It shows the strong potential of ML-driven oscillatory MF platforms in materials science and lays the foundation for automated NP development.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Multidisciplinary Sciences
Anzhelika Koldaeva, Hsieh-Fu Tsai, Amy Q. Shen, Simone Pigolotti
Summary: This study investigates the population genetics of Escherichia coli proliferating in microchannels, revealing that diversity is rapidly lost within channels but much slower among them. Competitive E. coli strains must organize into an ordered stripe pattern in a few generations. Random mutations in the middle of the channel are more likely to become fixed, illustrating fundamental mechanisms of microbial evolution in spatially confined environments.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Chemistry, Analytical
Hsieh-Fu Tsai, Daniel W. Carlson, Anzhelika Koldaeva, Simone Pigolotti, Amy Q. Shen
Summary: In this work, an integrated and hydrodynamically-optimized microfluidic chip was designed and fabricated to study the long-term dynamics of Escherichia coli populations in confined microchannels. By using a microscopy immersion oil with stable viscosity, successful time-lapse imaging of the bacteria was achieved for more than 72 hours. This fabrication and imaging methodology could be applicable to other single-cell studies that require long-term imaging.
Article
Biophysics
Riccardo Funari, Hidehiro Fukuyama, Amy Q. Shen
Summary: A multiplex nanoplasmonic biosensor has been developed to capture the humoral response against multiple antigens, providing a cost-effective and efficient alternative for serological analysis. The platform has demonstrated successful profiling of multiple serum antibodies and can be integrated with microfluidics for high throughput screening in vaccine development.
BIOSENSORS & BIOELECTRONICS
(2022)
Article
Polymer Science
Vincenzo Calabrese, Stylianos Varchanis, Simon J. Haward, Amy Q. . Shen
Summary: Understanding the hydrodynamic alignment of colloidal rods in polymer solutions is crucial for producing structurally ordered materials. This study analyzes the alignment of colloidal rods suspended in polymer solutions and compares it to the case where additional colloidal rods provide crowding in a pure solvent. The dynamics of the polymer is found to govern the shear-induced alignment of colloidal rods, with the Weissenberg number as the control parameter for alignment. Additionally, it is shown that the alignment of colloidal rods follows a universal trend regardless of the crowding environment.
Letter
Mechanics
San To Chan, Simon J. Haward, Amy Q. Shen
Summary: Edge fracture, a common problem in measuring rheological properties of viscoelastic fluids at high shear rates, can be delayed by sealing the fluid's free surface with nontoxic liquid metal Galinstan. This approach extends the measurable shear rate range of a cone-and-plate fixture significantly, compared to the existing method of using a cone-partitioned plate fixture. The inexpensive yet effective method proposed in this study will benefit the general rheological study of complex fluids.
Article
Biochemical Research Methods
Vincenzo Calabrese, Amy Q. Q. Shen, Simon J. J. Haward
Summary: This article analyzes the structural dynamics of naturally derived colloidal rods (CR) under microfluidic flows, focusing on shear- and extensional-dominated flows. It highlights the importance of understanding key concepts when evaluating results from different CR and microfluidic platforms, and suggests future research directions.
Article
Chemistry, Multidisciplinary
Vincenzo Mazzaracchio, Mauricio Rios Maciel, Tatiana Porto Santos, Kazumi Toda-Peters, Amy Q. Shen
Summary: A duplex electrochemical immunosensor is developed for simultaneous detection of anti-nucleocapsid IgG (N-IgG) and anti-spike IgG (S-IgG) using a two-working electrode system and differential pulse voltammetry. The sensor exhibits enhanced performance by modifying the screen-printed electrodes with carbon black and electrodeposited gold nanoflowers. It achieves a wide linear range and low detection limits for N-IgG and S-IgG detection in serum samples. Integrated into a microfluidic device, the duplex immunosensor enables high throughput screening for COVID-19 and other infectious diseases with significantly reduced detection time.
Review
Physics, Fluids & Plasmas
Charlotte de Blois, Simon J. Haward, Amy Q. Shen
Summary: In the flow of viscoelastic fluids over a microfluidic canopy, waves in the form of low flow velocity regions compared to the surrounding flow spontaneously emerge. The occurrence of these waves is chaotic and exhibits characteristics of elastic turbulence. By combining flow velocimetry experiments and high-speed tracking of the pillars, we systematically study the coupling between the low-velocity waves and the microfluidic canopy.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Biochemistry & Molecular Biology
Marvin Detert, Tatiana Porto Santos, Amy Q. Shen, Vincenzo Calabrese
Summary: The relationship between the alignment of biosourced rod-like colloids (RC) and rod-like polymers (RP) and the rheological properties of the fluid is investigated. It is found that the alignment of RC and RP contributes to the viscosity of the fluid in a consistent manner across different systems, independent of concentration. A dimensionless parameter (& beta;) directly proportional to the specific viscosity (& eta;(sp)) at zero shear rate (& eta;(0,sp)) is also identified.
Article
Mechanics
Simon J. Haward, Francisco Pimenta, Stylianos Varchanis, Daniel W. Carlson, Kazumi Toda-Peters, Manuel A. Alves, Amy Q. Q. Shen
Summary: Numerical optimization of a six-arm cross-slot device generates three-dimensional fluidic channel shapes that approximate ideal uniaxial (biaxial) stagnation point extensional flow. One of the designed geometries is suitable for microfabrication and achieves optimal flow fields for both Newtonian and viscoelastic fluids. The geometry is called OUBER and is fabricated with high precision by laser-induced etching. Microtomographic-particle image velocimetry measurements confirm accurate imposition of desired flows in a wide region around the stagnation point. In Part II of the paper, pressure drop measurements in the OUBER geometry are used to evaluate extensional rheometry of dilute polymeric solutions compared to planar extension measurements using OSCER.
JOURNAL OF RHEOLOGY
(2023)
Article
Mechanics
Simon J. Haward, Stylianos Varchanis, Gareth H. McKinley, Manuel A. Alves, Amy Q. Shen
Summary: Part I presents a microfluidic device for generating near-homogeneous uniaxial and biaxial elongational flows. In Part II, this device is used to examine the extensional rheology of dilute polymer solutions compared to measurements made under planar extension. The extension rate and tensile stress difference generated in the fluid are measured using micro-particle image velocimetry and excess pressure drop measurements. The results show that at higher polymer concentrations, the experimental measurements deviate from the model predictions due to intermolecular interactions as the polymer chains unravel in the extensional flows.
JOURNAL OF RHEOLOGY
(2023)
Article
Mechanics
San To Chan, Stylianos Varchanis, Simon J. Haward, Amy Q. Shen
Summary: Edge fracture is a viscoelastic instability that occurs when a fluid experiences a high shear rate, causing sudden indentation of its free surface. This fracture can affect rheological measurements and lead to complications in interpreting experimental results. Through empirical and theoretical research, the physics of edge fracture has been unraveled, enabling rheologists to develop techniques for reducing its adverse effects. Furthermore, edge fracture has potential applications in breaking viscoelastic liquid bridges, making it useful for functional dispensing nozzles.
JOURNAL OF RHEOLOGY
(2023)
Article
Mechanics
M. A. Kanso, V. Calabrese, Amy Q. Q. Shen, Myong Chol Pak, A. J. Giacomin
Summary: Bacteriophages are viruses that attack bacteria by attaching to their receptors, and their reorientation relies on Brownian motion and rotational components. In this study, the rotational diffusivity of Pf1, a type of bacteriophage, was determined through rheological measurements and compared with theoretical predictions. The results showed that the dimensionless rotational diffusivity differed by approximately one order of magnitude from the value obtained from fluorescence microscopy. Good agreement was found between theoretical predictions and complex viscosity measurements at low frequency.
Article
Chemistry, Physical
Arisa Yokokoji, Stylianos Varchanis, Amy Q. Shen, Simon J. Haward
Summary: Viscoelastic flows in the cross-slot geometry can transition from a steady symmetric state to a steady asymmetric state. This transition may be due to purely-elastic effects beyond a critical flow rate, or shear thinning of the fluid's viscosity. The interplay between fluid elasticity and shear thinning affects the onset and development of asymmetric flows. Experimental results and numerical simulations reveal the importance of shear thinning and fluid elasticity in controlling elastic instabilities in the cross-slot geometry.
Article
Multidisciplinary Sciences
San To Chan, Stylianos Varchanis, Amy Q. Shen, Simon J. Haward
Summary: This study investigates the possibility of using torsion to break liquid bridges of complex thixotropic elastoviscoplastic fluids and demonstrates its potential application in improving the dispensing of real industrial fluids. Through simulation and dimensional analysis, a better understanding of the liquid bridge breaking mechanism is achieved.
Article
Energy & Fuels
Laura L. Trinkies, Marlene Crone, Michael Tuerk, Manfred Kraut, Roland Dittmeyer
Summary: In this study, mono- and bimetallic Pd and Pt catalysts were deposited via supercritical fluid reactive deposition (SFRD) on TiO2 coated additively manufactured substrates. The focus of this work was to evaluate the suitability of these catalysts for the direct synthesis of H2O2 in the liquid phase. The results showed that all catalysts exhibited high activity and productivity, with PdPt bimetallic catalysts showing the highest productivity and an increase in Pd loading leading to a decrease in productivity. Comparison with literature data demonstrated the high suitability of the SFRD method for the proposed application, with the added benefits of simplicity and environmental friendliness in catalyst production.
CHEMICAL ENGINEERING AND PROCESSING-PROCESS INTENSIFICATION
(2024)
Article
Energy & Fuels
Xiongbao Hu, Zuguo Shen, Yu Wang
Summary: It is impossible to control the outer wall temperature of the micro-combustor below the maximum allowable temperature of commercial thermoelectric generators simply through increasing the equivalent heat transfer coefficient. Three simple strategies were developed to improve temperature uniformity, yet none of them could ensure full temperature control.
CHEMICAL ENGINEERING AND PROCESSING-PROCESS INTENSIFICATION
(2024)
