scholarly journals Precise pooling and dispensing of microfluidic droplets towards micro- to macro-world interfacing

RSC Advances ◽  
2014 ◽  
Vol 4 (73) ◽  
pp. 38542-38550 ◽  
Author(s):  
Eric Brouzes ◽  
April Carniol ◽  
Tomasz Bakowski ◽  
Helmut H. Strey
Keyword(s):  
Microfluidic Device ◽  
Droplet Microfluidics ◽  
Seamless Integration ◽  
Microfluidic Droplets ◽  
Microtiter Plates

We present the design of a microfluidic device that accurately and automatically pools and delivers a precise number of droplets. It will permit the interfacing of the microfluidic world to the macrofluidic world (e.g. microtiter plates) and will allow the seamless integration of droplet microfluidics into already developed robotic workflows.

scholarly journals Interfacial Tension Measurements in Microfluidic Quasi-Static Extensional Flows

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 272
Author(s):  
Doojin Lee ◽  
Amy Q. Shen
Keyword(s):  
Interfacial Tension ◽  
Microfluidic Device ◽  
Extensional Flow ◽  
Immiscible Fluids ◽  
Droplet Microfluidics ◽  
Channel Height ◽  
Deformation Model ◽  
Droplet Deformation ◽  
Extensional Flows ◽  
2D Model

Droplet microfluidics provides a versatile tool for measuring interfacial tensions between two immiscible fluids owing to its abilities of fast response, enhanced throughput, portability and easy manipulations of fluid compositions, comparing to conventional techniques. Purely homogeneous extension in the microfluidic device is desirable to measure the interfacial tension because the flow field enables symmetric droplet deformation along the outflow direction. To do so, we designed a microfluidic device consisting of a droplet production region to first generate emulsion droplets at a flow-focusing area. The droplets are then trapped at a stagnation point in the cross junction area, subsequently being stretched along the outflow direction under the extensional flow. These droplets in the device are either confined or unconfined in the channel walls depending on the channel height, which yields different droplet deformations. To calculate the interfacial tension for confined and unconfined droplet cases, quasi-static 2D Darcy approximation model and quasi-static 3D small deformation model are used. For the confined droplet case under the extensional flow, an effective viscosity of the two immiscible fluids, accounting for the viscosity ratio of continuous and dispersed phases, captures the droplet deformation well. However, the 2D model is limited to the case where the droplet is confined in the channel walls and deforms two-dimensionally. For the unconfined droplet case, the 3D model provides more robust estimates than the 2D model. We demonstrate that both 2D and 3D models provide good interfacial tension measurements under quasi-static extensional flows in comparison with the conventional pendant drop method.

scholarly journals Negative Pressure Provides Simple and Stable Droplet Generation in a Flow-Focusing Microfluidic Device

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 662
Author(s):  
Nikita A. Filatov ◽  
Anatoly A. Evstrapov ◽  
Anton S. Bukatin
Keyword(s):  
Microfluidic Device ◽  
Negative Pressure ◽  
Low Cost ◽  
Control Valve ◽  
Droplet Microfluidics ◽  
Droplet Generation ◽  
Electric Signal ◽  
Absolute Pressure ◽  
Flow Focusing ◽  
Wide Range

Droplet microfluidics is an extremely useful and powerful tool for industrial, environmental, and biotechnological applications, due to advantages such as the small volume of reagents required, ultrahigh-throughput, precise control, and independent manipulations of each droplet. For the generation of monodisperse water-in-oil droplets, usually T-junction and flow-focusing microfluidic devices connected to syringe pumps or pressure controllers are used. Here, we investigated droplet-generation regimes in a flow-focusing microfluidic device induced by the negative pressure in the outlet reservoir, generated by a low-cost mini diaphragm vacuum pump. During the study, we compared two ways of adjusting the negative pressure using a compact electro-pneumatic regulator and a manual airflow control valve. The results showed that both types of regulators are suitable for the stable generation of monodisperse droplets for at least 4 h, with variations in diameter less than 1 µm. Droplet diameters at high levels of negative pressure were mainly determined by the hydrodynamic resistances of the inlet microchannels, although the absolute pressure value defined the generation frequency; however, the electro-pneumatic regulator is preferable and convenient for the accurate control of the pressure by an external electric signal, providing more stable pressure, and a wide range of droplet diameters and generation frequencies. The method of droplet generation suggested here is a simple, stable, reliable, and portable way of high-throughput production of relatively large volumes of monodisperse emulsions for biomedical applications.

Quantum-dot-encapsulated core–shell barcode particles from droplet microfluidics

2018 ◽  
Vol 6 (44) ◽  
pp. 7257-7262 ◽  
Author(s):  
Feika Bian ◽  
Huan Wang ◽  
Lingyu Sun ◽  
Yuxiao Liu ◽  
Yuanjin Zhao
Keyword(s):  
Quantum Dot ◽  
Microfluidic Device ◽  
Biomedical Applications ◽  
Droplet Microfluidics ◽  
Core Shell ◽  
New Class

A new class of QD-encapsulated core–shell barcode particles for biomedical applications were generated using a capillary microfluidic device.

A Microfluidic Platform for Multi-Antigen Immunofluorescence Assays

2011 ◽  
Vol 108 ◽  
pp. 200-205 ◽  
Author(s):  
Bao Yue Zhang ◽  
Hui Xue Song ◽  
Tan Chen ◽  
Zhan Hui Wang
Keyword(s):  
Stem Cells ◽  
Microfluidic Device ◽  
Cell Types ◽  
Magnetic Bead ◽  
Immunofluorescence Assay ◽  
Human Umbilical Cord Blood ◽  
Human Umbilical Cord ◽  
Microtiter Plates ◽  
Hla Dr ◽  
Antigen Antibody

Traditional cell-based assays such as cell immunoassay that utilizes plastic (chamber slides, dishes, microtiter plates), Magnetic bead, enzyme-linked immunsorbent assays (ELISA) [1], FACS cell sorting is labor intensive, time consuming, and requires a large numbers of cells or reagents. In this report, a microfluidic device integrated with cell culture, washing, fixation, and antigen-antibody reaction is presented for high-throughput immunoassay. Using this microfluidic device, each assay can be performed on a small number of cells and nanolitre or picolitre of reagents, this is particularly beneficial for rare or expensive cell types such as stem cells, or flow sorted cell populations. The capability of the microfluidic device was demonstrated for seeding human umbilical cord blood mesenchymal stem cells (UC-MSCs) in chambers and detecting the expression of surface markers (CD34, CD44, CD45, CD73, CD105, HLA-DR) by immunofluorescence assay.

scholarly journals High diversity droplet microfluidic libraries generated with a commercial liquid spotter

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jesse Q. Zhang ◽  
Christian A. Siltanen ◽  
Ata Dolatmoradi ◽  
Chen Sun ◽  
Kai-Chun Chang ◽  
...  
Keyword(s):  
Chemical Synthesis ◽  
Microfluidic Device ◽  
Droplet Microfluidics ◽  
Droplet Generator ◽  
Manual Operation ◽  
Multiplexed Pcr ◽  
User Intervention ◽  
High Diversity

AbstractDroplet libraries consisting of many reagents encapsulated in separate droplets are necessary for applications of microfluidics, including combinatorial chemical synthesis, DNA-encoded libraries, and massively multiplexed PCR. However, existing approaches for generating them are laborious and impractical. Here, we describe an automated approach using a commercial array spotter. The approach can controllably emulsify hundreds of different reagents in a fraction of the time of manual operation of a microfluidic device, and without any user intervention. We demonstrate that the droplets produced by the spotter are similarly uniform to those produced by microfluidics and automate the generation of a ~ 2 mL emulsion containing 192 different reagents in ~ 4 h. The ease with which it can generate high diversity droplet libraries should make combinatorial applications more feasible in droplet microfluidics. Moreover, the instrument serves as an automated droplet generator, allowing execution of droplet reactions without microfluidic expertise.

A photofabricated honeycomb micropillar array for loss-free trapping of microfluidic droplets and application to digital PCR

Lab on a Chip ◽  
2021 ◽  
Author(s):  
Yu He ◽  
Zefan Lu ◽  
Hongliang Fan ◽  
Tao Zhang
Keyword(s):  
Biomedical Applications ◽  
Digital Pcr ◽  
Droplet Microfluidics ◽  
Microfluidic Droplets ◽  
Micropillar Array

Droplet microfluidics is a promising platform for various biological and biomedical applications. Among which, droplet-based digital PCR (ddPCR) is one of the most challenging examples, with practical issues involving possible...

scholarly journals Microfluidic Device for Droplet Pairing by Combining Droplet Railing and Floating Trap Arrays

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1076
Author(s):  
Margaux Duchamp ◽  
Marion Arnaud ◽  
Sara Bobisse ◽  
George Coukos ◽  
Alexandre Harari ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Droplet Size ◽  
Microfluidic Device ◽  
Microfluidic Chip ◽  
High Efficiency ◽  
Droplet Microfluidics ◽  
Trapping Efficiency ◽  
Unique Combination ◽  
Chip Design ◽  
Single Droplets

Droplet microfluidics are characterized by the generation and manipulation of discrete volumes of solutions, generated with the use of immiscible phases. Those droplets can then be controlled, transported, analyzed or their content modified. In this wide droplet microfluidic toolbox, no means are available to generate, in a controlled manner, droplets co-encapsulating to aqueous phases. Indeed, current methods rely on random co-encapsulation of two aqueous phases during droplet generation or the merging of two random droplets containing different aqueous phases. In this study, we present a novel droplet microfluidic device to reliably and efficiently co-encapsulate two different aqueous phases in micro-droplets. In order to achieve this, we combined existing droplet microfluidic modules in a novel way. The different aqueous phases are individually encapsulated in droplets of different sizes. Those droplet populations are then filtered in order to position each droplet type towards its adequate trapping compartment in traps of a floating trap array. Single droplets, each containing a different aqueous phase, are thus paired and then merged. This pairing at high efficiency is achieved thanks to a unique combination of floating trap arrays, a droplet railing system and a droplet size-based filtering mechanism. The microfluidic chip design presented here provides a filtering threshold with droplets larger than 35 μm (big droplets) being deviated to the lower rail while droplets smaller than 20 μm (small droplets) remain on the upper rail. The effects of the rail height and the distance between the two (upper and lower) rails were investigated. The optimal trap dimensions provide a trapping efficiency of 100% for small and big droplets with a limited double trapping (both compartments of the traps filled with the same droplet type) of 5%. The use of electrocoalescence enables the generation of a droplet while co-encapsulating two aqueous phases. Using the presented microfluidic device libraries of 300 droplets, dual aqueous content can be generated in less than 30 min.

Quantifying the sol–gel process and detecting toxic gas in an array of anchored microfluidic droplets

Lab on a Chip ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 236-243 ◽  
Author(s):  
Laurent Mugherli ◽  
Adelaide Lety-Stefanska ◽  
Nina Landreau ◽  
Raphael F.-X. Tomasi ◽  
Charles N. Baroud
Keyword(s):  
Microfluidic Device ◽  
Sol Gel ◽  
Microfluidic Droplets ◽  
Toxic Gases ◽  
Gel Beads ◽  
Sol Gel Process ◽  
Toxic Gas ◽  
Sol Gel Transition ◽  
Gel Transition

The production of sol–gel beads, in situ within a microfluidic device, allows us to study the sol–gel transition with exquisite detail, as well measuring the presence of toxic gases using microfluidics.

scholarly journals Droplet Microfluidics for the ex Vivo Expansion of Human Primary Multiple Myeloma Cells

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 261
Author(s):  
Pilar Carreras ◽  
Iciar Gonzalez ◽  
Miguel Gallardo ◽  
Alejandra Ortiz-Ruiz ◽  
Joaquin Martinez-Lopez
Keyword(s):  
Stem Cells ◽  
Multiple Myeloma ◽  
Microfluidic Device ◽  
Ex Vivo ◽  
Droplet Microfluidics ◽  
Wide Field ◽  
Term Survival ◽  
Tissue Scaffold ◽  
Hematopoietic Stem ◽  
Myeloma Cells

We previously reported a new approach for micromanipulation and encapsulation of human stem cells using a droplet-based microfluidic device We demonstrated the possibility of encapsulating and culturing difficult-to-preserve primary human hematopoietic stem cells using an engineered double layered bead composed by an inner layer of alginate and an outer layer of puramatrix constructed using a soft technology without the use of any external force. In this work, we use this micro manipulation technique to build a 3D scaffold as a biomimetic model to recapitulate the niche of patient-derived multiple myeloma cells (MM cell) using a multilayered 3D tissue scaffold constructed in a microfluidic device and cultured in 10% FBS culture medium. In the current study, we included the use of this biomimetic model comprising supporting human Mesenchymal stem cells to show the mid-term survival of MM cells in the proposed structures. We found that the generated microniches were suitable for the maintenance of MM cells with and without supporting cells. Additionally, cultured MM cells in droplets were exposed to both Bortezomib and Lenalidomide to test their toxicity in the cultured patient derived cells. Results indicate that the maintained MM cells were consistently responding to the applied medication, opening a wide field of possibilities to use the presented micro device as an ex vivo platform for drug screening.

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