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1
Liu, Jingji, Boyang Zhang, Yajun Zhang, and Yiqiang Fan. "Fluid control with hydrophobic pillars in paper-based microfluidics." Journal of Micromechanics and Microengineering 31, no. 12 (2021): 127002. http://dx.doi.org/10.1088/1361-6439/ac35c9.
Testo completoAbstract (sommario):
Abstract Paper-based microfluidics has been widely used in chemical and medical analysis applications. In the conventional paper-based microfluidic approach, fluid is propagating inside the porous structure, and the flow direction of the fluid propagation is usually controlled with the pre-defined hydrophobic barrier (e.g. wax). However, the fluid propagation velocity inside the paper-based microfluidic devices largely depends on the material properties of paper and fluid, the relative control method is rarely reported. In this study, a fluid propagation velocity control method is proposed for paper-based microfluidics: hydrophobic pillar arrays with different configurations were deposited in the microchannels in paper-based microfluidics for flow speed control, the result indicates the deposited hydrophobic pillar arrays can effectively slow down the fluid propagation at different levels and can be used to passively control the fluid propagation inside microchannels for paper-based microfluidics. For the demonstration of the proposed fluid control methods, a paper-based microfluidic device for nitrite test in water was also fabricated. The proposed fluid control method for paper-based microfluidics may have significant importance for applications that involve sequenced reactions and more actuate fluid manipulation.
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LI, CHIYU, WANG LI, CHUNYANG GENG, HAIJUN REN, XIAOHUI YU, and BO LIU. "MICROFLUIDIC CHIP FOR CANCER CELL DETECTION AND DIAGNOSIS." Journal of Mechanics in Medicine and Biology 18, no. 01 (2018): 1830001. http://dx.doi.org/10.1142/s0219519418300016.
Testo completoAbstract (sommario):
Since cancer becomes the most deadly disease to our health, research on early detection on cancer cells is necessary for clinical treatment. The combination of microfluidic device with cell biology has shown a unique method for cancer cell research. In the present review, recent development on microfluidic chip for cancer cell detection and diagnosis will be addressed. Some typical microfluidic chips focussed on cancer cells and their advantages for different kinds of cancer cell detection and diagnosis will be listed, and the cell capture methods within the microfluidics will be simultaneously mentioned. Then the potential direction of microfluidic chip on cancer cell detection and diagnosis in the future is also discussed.
3
Switalla, Ander, Lael Wentland, and Elain Fu. "3D printing-based microfluidic devices in fabric." Journal of Micromechanics and Microengineering 33, no. 2 (2023): 027001. http://dx.doi.org/10.1088/1361-6439/acaff1.
Testo completoAbstract (sommario):
Abstract Fabric-based microfluidics is a growing sub-field of porous materials-based microfluidics. 3D printing has been demonstrated as a useful fabrication method for open channel microfluidic devices, and also in the context of porous substates such as cellulose. In the current report, we describe a straightforward method for 3D printing fabric-based microfluidic devices. We demonstrate the ability to create both full and partial barriers in fabric, characterizing minimum channel and barrier widths, as well as reproducibility of the method using the metric of flow time repeatability through the channels. We discuss considerations specific to 3D printing in fabric including fabric anisotropy, stretching, and nonuniformity. Further, we highlight our fabrication method via the implementation of a colorimetric urea assay.
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BAI, BOFENG, ZHENGYUAN LUO, TIANJIAN LU, and FENG XU. "NUMERICAL SIMULATION OF CELL ADHESION AND DETACHMENT IN MICROFLUIDICS." Journal of Mechanics in Medicine and Biology 13, no. 01 (2013): 1350002. http://dx.doi.org/10.1142/s0219519413500024.
Testo completoAbstract (sommario):
Inspired by the complex biophysical processes of cell adhesion and detachment under blood flow in vivo, numerous novel microfluidic devices have been developed to manipulate, capture, and separate bio-particles for various applications, such as cell analysis and cell enumeration. However, the underlying physical mechanisms are yet unclear, which has limited the further development of microfluidic devices and point-of-care (POC) systems. Mathematical modeling is an enabling tool to study the physical mechanisms of biological processes for its relative simplicity, low cost, and high efficiency. Recent development in computation technology for multiphase flow simulation enables the theoretical study of the complex flow processes of cell adhesion and detachment in microfluidics. Various mathematical methods (e.g., front tracking method, level set method, volume of fluid (VOF) method, fluid–solid interaction method, and particulate modeling method) have been developed to investigate the effects of cell properties (i.e., cell membrane, cytoplasma, and nucleus), flow conditions, and microchannel structures on cell adhesion and detachment in microfluidic channels. In this paper, with focus on our own simulation results, we review these methods and compare their advantages and disadvantages for cell adhesion/detachment modeling. The mathematical approaches discussed here would allow us to study microfluidics for cell capture and separation, and to develop more effective POC devices for disease diagnostics.
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Xi, Wang, Fang Kong, Joo Chuan Yeo, et al. "Soft tubular microfluidics for 2D and 3D applications." Proceedings of the National Academy of Sciences 114, no. 40 (2017): 10590–95. http://dx.doi.org/10.1073/pnas.1712195114.
Testo completoAbstract (sommario):
Microfluidics has been the key component for many applications, including biomedical devices, chemical processors, microactuators, and even wearable devices. This technology relies on soft lithography fabrication which requires cleanroom facilities. Although popular, this method is expensive and labor-intensive. Furthermore, current conventional microfluidic chips precludes reconfiguration, making reiterations in design very time-consuming and costly. To address these intrinsic drawbacks of microfabrication, we present an alternative solution for the rapid prototyping of microfluidic elements such as microtubes, valves, and pumps. In addition, we demonstrate how microtubes with channels of various lengths and cross-sections can be attached modularly into 2D and 3D microfluidic systems for functional applications. We introduce a facile method of fabricating elastomeric microtubes as the basic building blocks for microfluidic devices. These microtubes are transparent, biocompatible, highly deformable, and customizable to various sizes and cross-sectional geometries. By configuring the microtubes into deterministic geometry, we enable rapid, low-cost formation of microfluidic assemblies without compromising their precision and functionality. We demonstrate configurable 2D and 3D microfluidic systems for applications in different domains. These include microparticle sorting, microdroplet generation, biocatalytic micromotor, triboelectric sensor, and even wearable sensing. Our approach, termed soft tubular microfluidics, provides a simple, cheaper, and faster solution for users lacking proficiency and access to cleanroom facilities to design and rapidly construct microfluidic devices for their various applications and needs.
6
Yip, Hon Ming, John C. S. Li, Kai Xie, et al. "Automated Long-Term Monitoring of Parallel Microfluidic Operations Applying a Machine Vision-Assisted Positioning Method." Scientific World Journal 2014 (2014): 1–14. http://dx.doi.org/10.1155/2014/608184.
Testo completoAbstract (sommario):
As microfluidics has been applied extensively in many cell and biochemical applications, monitoring the related processes is an important requirement. In this work, we design and fabricate a high-throughput microfluidic device which contains 32 microchambers to perform automated parallel microfluidic operations and monitoring on an automated stage of a microscope. Images are captured at multiple spots on the device during the operations for monitoring samples in microchambers in parallel; yet the device positions may vary at different time points throughout operations as the device moves back and forth on a motorized microscopic stage. Here, we report an image-based positioning strategy to realign the chamber position before every recording of microscopic image. We fabricate alignment marks at defined locations next to the chambers in the microfluidic device as reference positions. We also develop image processing algorithms to recognize the chamber positions in real-time, followed by realigning the chambers to their preset positions in the captured images. We perform experiments to validate and characterize the device functionality and the automated realignment operation. Together, this microfluidic realignment strategy can be a platform technology to achieve precise positioning of multiple chambers for general microfluidic applications requiring long-term parallel monitoring of cell and biochemical activities.
7
Hamad, Eyad M., Ahmed Albagdady, Samer Al-Gharabli, et al. "Optimizing Rapid Prototype Development Through Femtosecond Laser Ablation and Finite Element Method Simulation for Enhanced Separation in Microfluidics." Journal of Nanofluids 12, no. 7 (2023): 1868–79. http://dx.doi.org/10.1166/jon.2023.2102.
Testo completoAbstract (sommario):
In recent years, microfluidic systems have emerged as promising tools for blood separation and analysis. However, conventional methods for prototyping microfluidic systems can be slow and expensive. In this study, we present a novel approach to rapid prototyping that combines femtosecond laser ablation and finite element method (FEM) simulation. The optimization of the prototyping process was achieved through systematic characterization of the laser ablation process and the application of FEM simulation to predict the flow behavior of the microfluidic devices. Using a dean-coupled inertial flow device (DCIFD) that comprises one channel bend and three outlets side-channels. DCIF is a phenomenon that occurs in curved microfluidic channels and is considered by the existence of inconsequential flow patterns perpendicular to the main flow direction. The DCIF can enhance the separation efficiency in microfluidic devices by inducing lateral migration of particles or cells towards specific locations along the channel. This lateral migration can be controlled by adjusting the curvature and dimensions of the channel, as well as the flow rate and properties of the fluid. Overall, DCIF can provide a valuable means of achieving efficient and high-throughput separation of particles or cells in microfluidic devices. Therefore, various microfluidics designs that contain different outlet channels were studied in this research to improve blood plasma separation efficiency. Results from imitated blood flow experiments showed positive results for fluid flow and particle separation. The study also found that incorporating three various channel widths is the key to achieving efficient plasma separation, indicating that this result could serve as a guideline for future microfluidics geometry specifications in the field of blood plasma separation. According to the FEM simulation, the highest separation percentage for both microparticle sizes was obtained by incorporating a variable outlet channel width into the same microfluidic device. The FEM simulation revealed that around 95% of the larger microparticles separated while 98% of the smaller microparticles separated. This is consistent with the imitated blood separation results, which showed that 91% of the larger microparticles separated and around 93% of the smaller microparticles were separated. Overall, our results demonstrate that the combination of femtosecond laser ablation and FEM simulation significantly improved the prototyping speed and efficiency while maintaining high blood separation performance.
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Khodamoradi, Maedeh, Saeed Rafizadeh Tafti, Seyed Ali Mousavi Shaegh, Behrouz Aflatoonian, Mostafa Azimzadeh, and Patricia Khashayar. "Recent Microfluidic Innovations for Sperm Sorting." Chemosensors 9, no. 6 (2021): 126. http://dx.doi.org/10.3390/chemosensors9060126.
Testo completoAbstract (sommario):
Sperm selection is a clinical need for guided fertilization in men with low-quality semen. In this regard, microfluidics can provide an enabling platform for the precise manipulation and separation of high-quality sperm cells through applying various stimuli, including chemical agents, mechanical forces, and thermal gradients. In addition, microfluidic platforms can help to guide sperms and oocytes for controlled in vitro fertilization or sperm sorting using both passive and active methods. Herein, we present a detailed review of the use of various microfluidic methods for sorting and categorizing sperms for different applications. The advantages and disadvantages of each method are further discussed and future perspectives in the field are given.
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Soitu, Cristian, Alexander Feuerborn, Cyril Deroy, Alfonso A. Castrejón-Pita, Peter R. Cook, and Edmond J. Walsh. "Raising fluid walls around living cells." Science Advances 5, no. 6 (2019): eaav8002. http://dx.doi.org/10.1126/sciadv.aav8002.
Testo completoAbstract (sommario):
An effective transformation of the cell culture dishes that biologists use every day into microfluidic devices would open many avenues for miniaturizing cell-based workflows. In this article, we report a simple method for creating microfluidic arrangements around cells already growing on the surface of standard petri dishes, using the interface between immiscible fluids as a “building material.” Conventional dishes are repurposed into sophisticated microfluidic devices by reshaping, on demand, the fluid structures around living cells. Moreover, these microfluidic arrangements can be further reconfigured during experiments, which is impossible with most existing microfluidic platforms. The method is demonstrated using workflows involving cell cloning, the selection of a particular clone from among others in a dish, drug treatments, and wound healing. The versatility of the approach and its biologically friendly aspects may hasten uptake by biologists of microfluidics, so the technology finally fulfills its potential.
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Bogseth, Amanda, Jian Zhou, and Ian Papautsky. "Evaluation of Performance and Tunability of a Co-Flow Inertial Microfluidic Device." Micromachines 11, no. 3 (2020): 287. http://dx.doi.org/10.3390/mi11030287.
Testo completoAbstract (sommario):
Microfluidics has gained a lot of attention for biological sample separation and purification methods over recent years. From many active and passive microfluidic techniques, inertial microfluidics offers a simple and efficient method to demonstrate various biological applications. One prevalent limitation of this method is its lack of tunability for different applications once the microfluidic devices are fabricated. In this work, we develop and characterize a co-flow inertial microfluidic device that is tunable in multiple ways for adaptation to different application requirements. In particular, flow rate, flow rate ratio and output resistance ratio are systematically evaluated for flexibility of the cutoff size of the device and modification of the separation performance post-fabrication. Typically, a mixture of single size particles is used to determine cutoff sizes for the outlets, yet this fails to provide accurate prediction for efficiency and purity for a more complex biological sample. Thus, we use particles with continuous size distribution (2–32 μm) for separation demonstration under conditions of various flow rates, flow rate ratios and resistance ratios. We also use A549 cancer cell line with continuous size distribution (12–27 μm) as an added demonstration. Our results indicate inertial microfluidic devices possess the tunability that offers multiple ways to improve device performance for adaptation to different applications even after the devices are prototyped.
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Acosta-Cuevas, José M., Mario A. García-Ramírez, Gabriela Hinojosa-Ventura, Álvaro J. Martínez-Gómez, Víctor H. Pérez-Luna, and Orfil González-Reynoso. "Surface Roughness Analysis of Microchannels Featuring Microfluidic Devices Fabricated by Three Different Materials and Methods." Coatings 13, no. 10 (2023): 1676. http://dx.doi.org/10.3390/coatings13101676.
Testo completoAbstract (sommario):
In recent years, the utilization of microfluidic devices for precise manipulation of small flows has significantly increased. The effective management of microfluidics is closely associated with microchannel fabrication. The fabrication method employed for microfluidic devices directly impacts the roughness of the microchannels, consequently influencing the flows within them. In this study, the surface roughness of microchannels was investigated through three different fabrication processes: PDMS lithography, PLA printing, and UV resin printing. This research compared and analyzed the surface roughness of the microchannels fabricated using these methods. Furthermore, supported by a dynamic fluid simulator, the impact of surface roughness on flow behavior was shown. Results reveal varying degrees of roughness prominence in curved regions. Comparing microfluidic device fabrication techniques is crucial to optimize the process, control roughness, analyze flow rates, and select a proper material to be used in the development of microfluidic devices.
12
You, Jae Bem, Byungjin Lee, Yunho Choi, et al. "Nanoadhesive layer to prevent protein absorption in a poly(dimethylsiloxane) microfluidic device." BioTechniques 69, no. 1 (2020): 46–51. http://dx.doi.org/10.2144/btn-2020-0025.
Testo completoAbstract (sommario):
Poly(dimethylsiloxane) (PDMS) is widely used as a microfluidics platform material; however, it absorbs various molecules, perturbing specific chemical concentrations in microfluidic channels. We present a simple solution to prevent adsorption into a PDMS microfluidic device. We used a vapor-phase-deposited nanoadhesive layer to seal PDMS microfluidic channels. Absorption of fluorescent molecules into PDMS was efficiently prevented in the nanolayer-treated PDMS device. Importantly, when cultured in a nanolayer-treated PDMS device, yeast cells exhibited the expected concentration-dependent response to a mating pheromone, including mating-specific morphological and gene expression changes, while yeast cultured in an untreated PDMS device did not properly respond to the pheromone. Our method greatly expands microfluidic applications that require precise control of molecule concentrations.
13
Obaid, Rusl Mahdi, and Khdeeja Jabbar Ali. "New Spectrophotometric Reduction–Oxidation System for Methyldopa Determination in Different Pharmaceutical Models." Methods and Objects of Chemical Analysis 19, no. 1 (2024): 45–53. http://dx.doi.org/10.17721/moca.2024.45-53.
Testo completoAbstract (sommario):
Two spectrophotometric methods have been developed for the determination of methyldopa in the pure form and pharmaceutical formulations, both two methods based on the oxidation of the drug with an excess of N-Bromosuccinimide (NBS) and then reduction with 3,3-Diaminobenzidine (DAB), Absorbance of the resulting Magenta colored product is measured at 513 nm, the linearity ranged between (0.5 to 10) mg L−1 for the first spectroscopy method, and (0.5 to 15) mg L−1 for the second microfluid method. The detection limits (LOD) are 0.171, and 0.180 μg mL-1 for methyldopa in two methods spectroscopies, and microfluidic respectively. The limits of quantities (LOQ) are 0.571, and 0.600 μg mL-1 for methyldopa in two methods spectroscopies, and microfluidic respectively. The molar absorptivity (Ɛ) 2.58 ×104, 2.112×103 L mol-1 cm-1 for methyldopa in two methods spectroscopies, and microfluidic respectively. No interference was observed from common excipients in formulations. The results show a simple, accurate, fast, and readily applied method to the determination of methyldopa in pharmaceutical products. The proposed method was applied successfully for the determination of the drug in their pharmaceutical formulations.
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Yuan, Rodger, Jaemyon Lee, Hao-Wei Su, et al. "Microfluidics in structured multimaterial fibers." Proceedings of the National Academy of Sciences 115, no. 46 (2018): E10830—E10838. http://dx.doi.org/10.1073/pnas.1809459115.
Testo completoAbstract (sommario):
Traditional fabrication techniques for microfluidic devices utilize a planar chip format that possesses limited control over the geometry of and materials placement around microchannel cross-sections. This imposes restrictions on the design of flow fields and external forces (electric, magnetic, piezoelectric, etc.) that can be imposed onto fluids and particles. Here we report a method of fabricating microfluidic channels with complex cross-sections. A scaled-up version of a microchannel is dimensionally reduced through a thermal drawing process, enabling the fabrication of meters-long microfluidic fibers with nonrectangular cross-sectional shapes, such as crosses, five-pointed stars, and crescents. In addition, by codrawing compatible materials, conductive domains can be integrated at arbitrary locations along channel walls. We validate this technology by studying unexplored regimes in hydrodynamic flow and by designing a high-throughput cell separation device. By enabling these degrees of freedom in microfluidic device design, fiber microfluidics provides a method to create microchannel designs that are inaccessible using planar techniques.
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Tanjaya, Hengky, and Christian Harito. "Integrating Microfluidic and Biosensors: A Mini Review." Journal of Physics: Conference Series 2705, no. 1 (2024): 012018. http://dx.doi.org/10.1088/1742-6596/2705/1/012018.
Testo completoAbstract (sommario):
Abstract In recent years, the field of analytical research has witnessed a significant transformation driven by the emergence of integrated microfluidic sensors. This ground-breaking technology has been extensively studied, resulting in the resolution of diverse challenges and a revolutionary impact on experiments, particularly in the biomedical domain. By combining the biosensors with microfluidics, there is a tremendous potential to enhance measurement accuracy and expand the capacity of specimens utilized in biomedical applications and experiments. The integration of biosensors with microfluidics enables effective sample separation, precise control over chemical reactions, and the measurement of various critical parameters. Furthermore, the primary objective of this research is to identify gaps in the existing literature concerning integrated microfluidic sensors. This pursuit involves employing comprehensive bibliometric analysis and conducting a systematic literature review of Scopus-indexed publications that are relevant to the field of integrated microfluidic sensors. PRISMA method was being used to filter the documents that are gathered from Scopus database. The outcomes of this study underscore the pressing need for further research in leveraging electrochemical sensors for specimen analysis by integrating them with the advanced technique of microfluidics. The paper emphasizes the significance of continuous research and development efforts in the realm of integrated microfluidic sensors to fully exploit the potential of electrochemical sensors and enhance the overall research process.
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Cai, Jianchen, Jiaxi Jiang, Jinyun Jiang, et al. "Fabrication of Transparent and Flexible Digital Microfluidics Devices." Micromachines 13, no. 4 (2022): 498. http://dx.doi.org/10.3390/mi13040498.
Testo completoAbstract (sommario):
This study proposed a fabrication method for thin, film-based, transparent, and flexible digital microfluidic devices. A series of characterizations were also conducted with the fabricated digital microfluidic devices. For the device fabrication, the electrodes were patterned by laser ablation of 220 nm-thick indium tin oxide (ITO) layer on a 175 μm-thick polyethylene terephthalate (PET) substrate. The electrodes were insulated with a layer of 12 μm-thick polyethylene (PE) film as the dielectric layer, and finally, a surface treatment was conducted on PE film in order to enhance the hydrophobicity. The whole digital microfluidic device has a total thickness of less than 200 μm and is nearly transparent in the visible range. The droplet manipulation with the proposed digital microfluidic device was also achieved. In addition, a series of characterization studies were conducted as follows: the contact angles under different driving voltages, the leakage current density across the patterned electrodes, and the minimum driving voltage with different control algorithms and droplet volume were measured and discussed. The UV–VIS spectrum of the proposed digital microfluidic devices was also provided in order to verify the transparency of the fabricated device. Compared with conventional methods for the fabrication of digital microfluidic devices, which usually have opaque metal/carbon electrodes, the proposed transparent and flexible digital microfluidics could have significant advantages for the observation of the droplets on the digital microfluidic device, especially for colorimetric analysis using the digital microfluidic approach.
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James, Matthew, Richard A. Revia, Zachary Stephen, and Miqin Zhang. "Microfluidic Synthesis of Iron Oxide Nanoparticles." Nanomaterials 10, no. 11 (2020): 2113. http://dx.doi.org/10.3390/nano10112113.
Testo completoAbstract (sommario):
Research efforts into the production and application of iron oxide nanoparticles (IONPs) in recent decades have shown IONPs to be promising for a range of biomedical applications. Many synthesis techniques have been developed to produce high-quality IONPs that are safe for in vivo environments while also being able to perform useful biological functions. Among them, coprecipitation is the most commonly used method but has several limitations such as polydisperse IONPs, long synthesis times, and batch-to-batch variations. Recent efforts at addressing these limitations have led to the development of microfluidic devices that can make IONPs of much-improved quality. Here, we review recent advances in the development of microfluidic devices for the synthesis of IONPs by coprecipitation. We discuss the main architectures used in microfluidic device design and highlight the most prominent manufacturing methods and materials used to construct these microfluidic devices. Finally, we discuss the benefits that microfluidics can offer to the coprecipitation synthesis process including the ability to better control various synthesis parameters and produce IONPs with high production rates.
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Zhao, Xihong, Mei Li, and Yao Liu. "Microfluidic-Based Approaches for Foodborne Pathogen Detection." Microorganisms 7, no. 10 (2019): 381. http://dx.doi.org/10.3390/microorganisms7100381.
Testo completoAbstract (sommario):
Food safety is of obvious importance, but there are frequent problems caused by foodborne pathogens that threaten the safety and health of human beings worldwide. Although the most classic method for detecting bacteria is the plate counting method, it takes almost three to seven days to get the bacterial results for the detection. Additionally, there are many existing technologies for accurate determination of pathogens, such as polymerase chain reaction (PCR), enzyme linked immunosorbent assay (ELISA), or loop-mediated isothermal amplification (LAMP), but they are not suitable for timely and rapid on-site detection due to time-consuming pretreatment, complex operations and false positive results. Therefore, an urgent goal remains to determine how to quickly and effectively prevent and control the occurrence of foodborne diseases that are harmful to humans. As an alternative, microfluidic devices with miniaturization, portability and low cost have been introduced for pathogen detection. In particular, the use of microfluidic technologies is a promising direction of research for this purpose. Herein, this article systematically reviews the use of microfluidic technology for the rapid and sensitive detection of foodborne pathogens. First, microfluidic technology is introduced, including the basic concepts, background, and the pros and cons of different starting materials for specific applications. Next, the applications and problems of microfluidics for the detection of pathogens are discussed. The current status and different applications of microfluidic-based technologies to distinguish and identify foodborne pathogens are described in detail. Finally, future trends of microfluidics in food safety are discussed to provide the necessary foundation for future research efforts.
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Gao, Feng, Haoyu Sun, Xiang Li, and Pingnian He. "Leveraging avidin-biotin interaction to quantify permeability property of microvessels-on-a-chip networks." American Journal of Physiology-Heart and Circulatory Physiology 322, no. 1 (2022): H71—H86. http://dx.doi.org/10.1152/ajpheart.00478.2021.
Testo completoAbstract (sommario):
Our study developed a novel method that allows permeability coefficient to be measured in microvessels developed in nonpermeable microfluidic platforms using avidin-biotin technology. It overcomes the major limitation of nonpermeable microfluidic system and provides a simply designed easily executed and highly reproducible in vitro microvessel model with permeability accessibility. This model with in vivo-like endothelial junctions, glycocalyx, and permeability properties advances microfluidics in microvascular research, suitable for a wide range of biomedical and clinical applications.
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Ahmed, Isteaque, Katherine Sullivan, and Aashish Priye. "Multi-Resin Masked Stereolithography (MSLA) 3D Printing for Rapid and Inexpensive Prototyping of Microfluidic Chips with Integrated Functional Components." Biosensors 12, no. 8 (2022): 652. http://dx.doi.org/10.3390/bios12080652.
Testo completoAbstract (sommario):
Stereolithography based 3D printing of microfluidics for prototyping has gained a lot of attention due to several advantages such as fast production, cost-effectiveness, and versatility over traditional photolithography-based microfabrication techniques. However, existing consumer focused SLA 3D printers struggle to fabricate functional microfluidic devices due to several challenges associated with micron-scale 3D printing. Here, we explore the origins and mechanism of the associated failure modes followed by presenting guidelines to overcome these challenges. The prescribed method works completely with existing consumer class inexpensive SLA printers without any modifications to reliably print PDMS cast microfluidic channels with channel sizes as low as ~75 μm and embedded channels with channel sizes as low ~200 μm. We developed a custom multi-resin formulation by incorporating Polyethylene glycol diacrylate (PEGDA) and Ethylene glycol polyether acrylate (EGPEA) as the monomer units to achieve micron sized printed features with tunable mechanical and optical properties. By incorporating multiple resins with different mechanical properties, we were able to achieve spatial control over the stiffness of the cured resin enabling us to incorporate both flexible and rigid components within a single 3D printed microfluidic chip. We demonstrate the utility of this technique by 3D printing an integrated pressure-actuated pneumatic valve (with flexible cured resin) in an otherwise rigid and clear microfluidic device that can be fabricated in a one-step process from a single CAD file. We also demonstrate the utility of this technique by integrating a fully functional finger-actuated microfluidic pump. The versatility and accessibility of the demonstrated fabrication method have the potential to reduce our reliance on expensive and time-consuming photolithographic techniques for microfluidic chip fabrication and thus drastically lowering our barrier to entry in microfluidics research.
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Yang, Ning, Pan Wang, Chen Pan, Chang-Hua Xiang, Liang-Liang Xie, and Han-Ping Mao. "Compensation method of error caused from maladjustment of optical path based on microfluidic chip." Modern Physics Letters B 32, no. 34n36 (2018): 1840081. http://dx.doi.org/10.1142/s021798491840081x.
Testo completoAbstract (sommario):
Photometric detection plays a significant role in microfluidics technology. However, the mismatch between the solution concentration and the optical path length will increase detection error. In this study, we proposed a round microfluidic chip for concentration detection to obtain the continuous gradient distribution of concentration. The optimum absorbance can be found by dynamic accurately searching. The solution concentration will be accurately calculated finally according to the relationship between arc length and solution concentration. The overall detection process runs automatically. Under the optimization of injection velocity and concentration, the experimental result shows that the compensation ratio increases as the solution concentration increases. The compensation ratio in the detection of pesticide residue has already reached 14.22% and the reproducibility is acceptable. Therefore, this novel method lays the theoretical foundation for the research of high precision microfluidic photometric detection equipment.
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Adamopoulos, Christos, Asmaysinh Gharia, Ali Niknejad, Vladimir Stojanović, and Mekhail Anwar. "Microfluidic Packaging Integration with Electronic-Photonic Biosensors Using 3D Printed Transfer Molding." Biosensors 10, no. 11 (2020): 177. http://dx.doi.org/10.3390/bios10110177.
Testo completoAbstract (sommario):
Multiplexed sensing in integrated silicon electronic-photonic platforms requires microfluidics with both high density micro-scale channels and meso-scale features to accommodate for optical, electrical, and fluidic coupling in small, millimeter-scale areas. Three-dimensional (3D) printed transfer molding offers a facile and rapid method to create both micro and meso-scale features in complex multilayer microfluidics in order to integrate with monolithic electronic-photonic system-on-chips with multiplexed rows of 5 μm radius micro-ring resonators (MRRs), allowing for simultaneous optical, electrical, and microfluidic coupling on chip. Here, we demonstrate this microfluidic packaging strategy on an integrated silicon photonic biosensor, setting the basis for highly multiplexed molecular sensing on-chip.
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Tian, Yishen, Rong Hu, Guangshi Du, and Na Xu. "Microfluidic Chips: Emerging Technologies for Adoptive Cell Immunotherapy." Micromachines 14, no. 4 (2023): 877. http://dx.doi.org/10.3390/mi14040877.
Testo completoAbstract (sommario):
Adoptive cell therapy (ACT) is a personalized therapy that has shown great success in treating hematologic malignancies in clinic, and has also demonstrated potential applications for solid tumors. The process of ACT involves multiple steps, including the separation of desired cells from patient tissues, cell engineering by virus vector systems, and infusion back into patients after strict tests to guarantee the quality and safety of the products. ACT is an innovative medicine in development; however, the multi-step method is time-consuming and costly, and the preparation of the targeted adoptive cells remains a challenge. Microfluidic chips are a novel platform with the advantages of manipulating fluid in micro/nano scales, and have been developed for various biological research applications as well as ACT. The use of microfluidics to isolate, screen, and incubate cells in vitro has the advantages of high throughput, low cell damage, and fast amplification rates, which can greatly simplify ACT preparation steps and reduce costs. Moreover, the customizable microfluidic chips fit the personalized demands of ACT. In this mini-review, we describe the advantages and applications of microfluidic chips for cell sorting, cell screening, and cell culture in ACT compared to other existing methods. Finally, we discuss the challenges and potential outcomes of future microfluidics-related work in ACT.
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Abrishamkar, Afshin, Azadeh Nilghaz, Maryam Saadatmand, Mohammadreza Naeimirad, and Andrew J. deMello. "Microfluidic-assisted fiber production: Potentials, limitations, and prospects." Biomicrofluidics 16, no. 6 (2022): 061504. http://dx.doi.org/10.1063/5.0129108.
Testo completoAbstract (sommario):
Besides the conventional fiber production methods, microfluidics has emerged as a promising approach for the engineered spinning of fibrous materials and offers excellent potential for fiber manufacturing in a controlled and straightforward manner. This method facilitates low-speed prototype synthesis of fibers for diverse applications while providing superior control over reaction conditions, efficient use of precursor solutions, reagent mixing, and process parameters. This article reviews recent advances in microfluidic technology for the fabrication of fibrous materials with different morphologies and a variety of properties aimed at various applications. First, the basic principles, as well as the latest developments and achievements of microfluidic-based techniques for fiber production, are introduced. Specifically, microfluidic platforms made of glass, polymers, and/or metals, including but not limited to microfluidic chips, capillary-based devices, and three-dimensional printed devices are summarized. Then, fiber production from various materials, such as alginate, gelatin, silk, collagen, and chitosan, using different microfluidic platforms with a broad range of cross-linking agents and mechanisms is described. Therefore, microfluidic spun fibers with diverse diameters ranging from submicrometer scales to hundreds of micrometers and structures, such as cylindrical, hollow, grooved, flat, core–shell, heterogeneous, helical, and peapod-like morphologies, with tunable sizes and mechanical properties are discussed in detail. Subsequently, the practical applications of microfluidic spun fibers are highlighted in sensors for biomedical or optical purposes, scaffolds for culture or encapsulation of cells in tissue engineering, and drug delivery. Finally, different limitations and challenges of the current microfluidic technologies, as well as the future perspectives and concluding remarks, are presented.
25
Wang, Ji-Xiang, Wei Yu, Zhe Wu, Xiangdong Liu, and Yongping Chen. "Physics-based statistical learning perspectives on droplet formation characteristics in microfluidic cross-junctions." Applied Physics Letters 120, no. 20 (2022): 204101. http://dx.doi.org/10.1063/5.0086933.
Testo completoAbstract (sommario):
Size-controllable micro-droplets obtained in microfluidic cross-junctions are significant in microfluidics. Modeling and predictions in microfluidic-based droplet formation characteristics to date using various traditional theoretical or empirical correlations are far from satisfactory. Driven by unprecedented data volumes from microfluidic experiments and simulations, statistical learning can offer a powerful technique to extract data that can be interpreted into underlying fluid physics and modeling. This Letter historically combines the current experimental data and experimental/numerical data from previous publications as a microfluidics-based droplet formation characteristics database. Two supervised statistical learning algorithms, deep neural network and factorization-machine-based neural network (Deep-FM), were established to model and predict the formed droplet size in microfluidic cross-junctions. As a newly developed statistical learning code in 2017, the Deep-FM manifests a better prediction performance, where the average relative error was only 4.09% and nearly 98% of the data points had individual relative errors of 10% or less. Such high accuracy can be attributed to the outstanding interactions between high-order and low-order features of the Deep-FM framework. Another innovation in this Letter lies in the training dataset shrinkage and optimization without sacrificing the prediction accuracy. Such a method pioneers statistical learning algorithms in small-sample modeling problems, which is different from big data modeling and analyses. The improved statistical learning proposed in this Letter provides universal high-accuracy modeling for microfluidic-based droplet characteristics prediction, which can be an influential data-processing framework that can boost and probably transform current lines of microfluidic physics research and industrial applications.
26
Nguyen, Duong Thanh, Van Thi Thanh Tran, Huy Trung Nguyen, Hong Thi Cao, Thai Quoc Vu, and Dung Quang Trinh. "Preparation of microfluidics device from PMMA for liposome synthesis." Vietnam Journal of Science and Technology 61, no. 1 (2023): 84–90. http://dx.doi.org/10.15625/2525-2518/16577.
Testo completoAbstract (sommario):
Microfluidics has emerged in recent years as a technology that has advantages and is well suited for studying chemistry, biology, and physics at the microscale. A common material which has been widely use to fabricate the microfluidic system is thermoplastic materials. The method of fabricating microfluidic devices has been growing because of advantages such as high-quality feature replication, inexpensiveness, and ease of use. However, the major barrier to the utilization of thermoplastics is the lack of bonding methods for different plastic layers to close the microchannels. Therefore, this study focused on fabricating a microfluidic device on poly(methyl methacrylate) (PMMA) plates by laser engraving. The bonding technique for plastic layers has relied on the application of small amounts of ethanol with conditions of low temperatures (100 ⁰C), and relatively low pressures (5 tons) for 2 minutes. With this technique, the microfluidic device is created to operate stably, without leakage or cracking even under high pressure. The microfluidic device was applied to synthesize liposomes with a 5:1 ratio of syringe pump velocity between water and lipid solution. The size of liposomes after synthesis is 109.64 ± 4.62 nm (mean ± sd) and the PDI is in accordance with standard conditions (PDI < 0.200).
27
Kotz, Frederik, Markus Mader, Nils Dellen, et al. "Fused Deposition Modeling of Microfluidic Chips in Polymethylmethacrylate." Micromachines 11, no. 9 (2020): 873. http://dx.doi.org/10.3390/mi11090873.
Testo completoAbstract (sommario):
Polymethylmethacrylate (PMMA) is one of the most important thermoplastic materials and is a widely used material in microfluidics. However, PMMA is usually structured using industrial scale replication processes, such as hot embossing or injection molding, not compatible with rapid prototyping. In this work, we demonstrate that microfluidic chips made from PMMA can be 3D printed using fused deposition modeling (FDM). We demonstrate that using FDM microfluidic chips with a minimum channel cross-section of ~300 µm can be printed and a variety of different channel geometries and mixer structures are shown. The optical transparency of the chips is shown to be significantly enhanced by printing onto commercial PMMA substrates. The use of such commercial PMMA substrates also enables the integration of PMMA microstructures into the printed chips, by first generating a microstructure on the PMMA substrates, and subsequently printing the PMMA chip around the microstructure. We further demonstrate that protein patterns can be generated within previously printed microfluidic chips by employing a method of photobleaching. The FDM printing of microfluidic chips in PMMA allows the use of one of microfluidics’ most used industrial materials on the laboratory scale and thus significantly simplifies the transfer from results gained in the lab to an industrial product.
28
Liu, Xiao Wei, Xiao Wei Han, He Zhang, Xi Yun Jiang, and Lin Zhao. "A Microfluidic Chip Microwave Bonding Method Based on the PMMA." Key Engineering Materials 562-565 (July 2013): 561–65. http://dx.doi.org/10.4028/www.scientific.net/kem.562-565.561.
Testo completoAbstract (sommario):
A new bonding technique mainly for PMMA microfluidic chips is presented in this paper. In this technique, polymer microfluidic microchannels were bonded by microwave radiation. Its strength and time can be controlled accurately in watt and second level. There are so many techniques for mass-production of polymer microfluidic chip, such as heat bonding, ultrasonic bonding. However, we may find different kinds of shortages when we use these techniques. In this paper, the experiment result shows that microwave radiation’s strength and time have effects on microfluidic chip`s bonding strength. The microwave absorbing coating can also have a certain degree influence on microfluidic chip`s bonding strength.
29
Peng, Xing Yue (Larry), Pengxiang Su, Yaxin Guo, Jing Zhang, Linghan Peng, and Rongrong Zhang. "A Microfluidic Experimental Method for Studying Cell-to-Cell Exosome Delivery–Taking Stem Cell–Tumor Cell Interaction as a Case." International Journal of Molecular Sciences 24, no. 17 (2023): 13419. http://dx.doi.org/10.3390/ijms241713419.
Testo completoAbstract (sommario):
Cell-to-cell communication must occur through molecular transport in the intercellular fluid space. Nanoparticles, such as exosomes, diffuse or move more slowly in fluids than small molecules. To find a microfluidic technology for real-time exosome experiments on intercellular communication between living cells, we use the microfluidic culture dish’s quaternary ultra-slow microcirculation flow field to accumulate nanoparticles in a specific area. Taking stem cell–tumor cell interaction as an example, the ultra-slow microcirculatory flow field controls stem cell exosomes to interfere with tumor cells remotely. Under static coculture conditions (without microfluidics), the tumor cells near stem cells (<200 µm) show quick breaking through from its Matrigel drop to meet stem cells, but this ‘breaking through’ quickly disappears with increasing distance. In programmed ultra-slow microcirculation, stem cells induce tumor cells 5000 μm far at the site of exosome deposition (according to nanoparticle simulations). After 14 days of programmed coculture, the glomeration and migration of tumor cells were observed in the exosome deposition area. This example shows that the ultra-slow microcirculation of the microfluidic culture dish has good prospects in quantitative experiments to study exosome communication between living cells and drug development of cancer metastasis.
30
Mudrik, Jared M., Michael D. M. Dryden, Nelson M. Lafrenière, and Aaron R. Wheeler. "Strong and small: strong cation-exchange solid-phase extractions using porous polymer monoliths on a digital microfluidic platform." Canadian Journal of Chemistry 92, no. 3 (2014): 179–85. http://dx.doi.org/10.1139/cjc-2013-0506.
Testo completoAbstract (sommario):
We present the first method for digital microfluidics-based strong cation-exchange solid-phase extractions. Digital microfluidics is a microscale fluid handling technique in which liquid droplets are actuated over an array of electrodes by electrodynamic forces. Strong cation exchange has gained considerable importance in the field of proteomics as a separation mode for protein and peptide extractions. The marriage of these two techniques is achieved by incorporating sulphonate-functionalised porous polymer monolith discs onto digital microfluidic chips. By manipulating sample and solvent droplets onto and off of these porous polymer monoliths, proteins and peptides are extracted by controlling solution pH and ionic strength. This novel microscale extraction method has efficiency comparable to commercially available strong cation-exchange ZipTips and is highly effective for sample cleanup. We anticipate that this digital microfluidic strong cation-exchange extraction technique will prove useful for microscale proteomic analyses and other applications requiring separation of cationic compounds.
31
Soitu, Cristian, Alexander Feuerborn, Ann Na Tan, et al. "Microfluidic chambers using fluid walls for cell biology." Proceedings of the National Academy of Sciences 115, no. 26 (2018): E5926—E5933. http://dx.doi.org/10.1073/pnas.1805449115.
Testo completoAbstract (sommario):
Many proofs of concept have demonstrated the potential of microfluidics in cell biology. However, the technology remains inaccessible to many biologists, as it often requires complex manufacturing facilities (such as soft lithography) and uses materials foreign to cell biology (such as polydimethylsiloxane). Here, we present a method for creating microfluidic environments by simply reshaping fluids on a substrate. For applications in cell biology, we use cell media on a virgin Petri dish overlaid with an immiscible fluorocarbon. A hydrophobic/fluorophilic stylus then reshapes the media into any pattern by creating liquid walls of fluorocarbon. Microfluidic arrangements suitable for cell culture are made in minutes using materials familiar to biologists. The versatility of the method is demonstrated by creating analogs of a common platform in cell biology, the microtiter plate. Using this vehicle, we demonstrate many manipulations required for cell culture and downstream analysis, including feeding, replating, cloning, cryopreservation, lysis plus RT-PCR, transfection plus genome editing, and fixation plus immunolabeling (when fluid walls are reconfigured during use). We also show that mammalian cells grow and respond to stimuli normally, and worm eggs develop into adults. This simple approach provides biologists with an entrée into microfluidics.
32
Smith, Savanah, Marzhan Sypabekova, and Seunghyun Kim. "Double-Sided Tape in Microfluidics: A Cost-Effective Method in Device Fabrication." Biosensors 14, no. 5 (2024): 249. http://dx.doi.org/10.3390/bios14050249.
Testo completoAbstract (sommario):
The demand for easy-to-use, affordable, accessible, and reliable technology is increasing in biological, chemical, and medical research. Microfluidic devices have the potential to meet these standards by offering cost-effective, highly sensitive, and highly specific diagnostic tests with rapid performance and minimal sample volumes. Traditional microfluidic device fabrication methods, such as photolithography and soft lithography, are time-consuming and require specialized equipment and expertise, making them costly and less accessible to researchers and clinicians and limiting the applicability and potential of microfluidic devices. To address this, researchers have turned to using new low-cost materials, such as double-sided tape for microfluidic device fabrication, which offers simple and low-cost processes. The innovation of low-cost and easy-to-make microfluidic devices improves the potential for more devices to be transitioned from laboratories to commercialized products found in stores, offices, and homes. This review serves as a comprehensive summary of the growing interest in and use of double-sided tape-based microfluidic devices in the last 20 years. It discusses the advantages of using double-sided tape, the fabrication techniques used to create and bond microfluidic devices, and the limitations of this approach in certain applications.
33
TermehYousefi, Amin, Samira Bagheri, and Nahrizul Adib. "Integration of biosensors based on microfluidic: a review." Sensor Review 35, no. 2 (2015): 190–99. http://dx.doi.org/10.1108/sr-09-2014-697.
Testo completoAbstract (sommario):
Purpose – Biotechnology is closely associated to microfluidics. During the last decade, designs of microfluidic devices such as geometries and scales have been modified and improved according to the applications for better performance. Numerous sensor technologies existing in the industry has potential use for clinical applications. Fabrication techniques of microfluidics initially rooted from the electromechanical systems (EMS) technology. Design/methodology/approach – In this review, we emphasized on the most available manufacture approaches to fabricate microchannels, their applications and the properties which make them unique components in biological studies. Findings – Major fundamental and technological advances demonstrate the enhancing of capabilities and improving the reliability of biosensors based on microfluidic. Several researchers have been reported verity of methods to fabricate different devices based on EMS technology due to the electroconductivity properties and their small size of them. Therefore, controlled fabrication method of MEMS plays an important role to design and fabricate a highly selective detection of medical devices in a variety of biological fluids. Stable, tight and reliable monitoring devices for biological components still remains a massive challenge and several studies focused on MEMS to fabricate simple and easy monitoring devices. Originality/value – This paper is not submitted or under review in any other journal.
34
Garg, Mayank, Martin Christensen, Alexander Iles, Amit Sharma, Suman Singh, and Nicole Pamme. "Microfluidic-Based Electrochemical Immunosensing of Ferritin." Biosensors 10, no. 8 (2020): 91. http://dx.doi.org/10.3390/bios10080091.
Testo completoAbstract (sommario):
Ferritin is a clinically important biomarker which reflects the state of iron in the body and is directly involved with anemia. Current methods available for ferritin estimation are generally not portable or they do not provide a fast response. To combat these issues, an attempt was made for lab-on-a-chip-based electrochemical detection of ferritin, developed with an integrated electrochemically active screen-printed electrode (SPE), combining nanotechnology, microfluidics, and electrochemistry. The SPE surface was modified with amine-functionalized graphene oxide to facilitate the binding of ferritin antibodies on the electrode surface. The functionalized SPE was embedded in the microfluidic flow cell with a simple magnetic clamping mechanism to allow continuous electrochemical detection of ferritin. Ferritin detection was accomplished via cyclic voltammetry with a dynamic linear range from 7.81 to 500 ng·mL−1 and an LOD of 0.413 ng·mL−1. The sensor performance was verified with spiked human serum samples. Furthermore, the sensor was validated by comparing its response with the response of the conventional ELISA method. The current method of microfluidic flow cell-based electrochemical ferritin detection demonstrated promising sensitivity and selectivity. This confirmed the plausibility of using the reported technique in point-of-care testing applications at a much faster rate than conventional techniques.
35
Russom, Aman, Palaniappan Sethu, Daniel Irimia, et al. "Microfluidic Leukocyte Isolation for Gene Expression Analysis in Critically Ill Hospitalized Patients." Clinical Chemistry 54, no. 5 (2008): 891–900. http://dx.doi.org/10.1373/clinchem.2007.099150.
Testo completoAbstract (sommario):
Abstract Background: Microarray technology is becoming a powerful tool for diagnostic, therapeutic, and prognostic applications. There is at present no consensus regarding the optimal technique to isolate nucleic acids from blood leukocyte populations for subsequent expression analyses. Current collection and processing techniques pose significant challenges in the clinical setting. Here, we report the clinical validation of a novel microfluidic leukocyte nucleic acid isolation technique for gene expression analysis from critically ill, hospitalized patients that can be readily used on small volumes of blood. Methods: We processed whole blood from hospitalized patients after burn injury and severe blunt trauma according to the microfluidic and standard macroscale leukocyte isolation protocol. Side-by-side comparison of RNA quantity, quality, and genome-wide expression patterns was used to clinically validate the microfluidic technique. Results: When the microfluidic protocol was used for processing, sufficient amounts of total RNA were obtained for genome-wide expression analysis from 0.5 mL whole blood. We found that the leukocyte expression patterns from samples processed using the 2 protocols were concordant, and there was less variability introduced as a result of harvesting method than there existed between individuals. Conclusions: The novel microfluidic approach achieves leukocyte isolation in &lt;25 min, and the quality of nucleic acids and genome expression analysis is equivalent to or surpasses that obtained from macroscale approaches. Microfluidics can significantly improve the isolation of blood leukocytes for genomic analyses in the clinical setting.
36
Yin, Zhifu, and Helin Zou. "A fast and simple bonding method for low cost microfluidic chip fabrication." Journal of Electrical Engineering 69, no. 1 (2018): 72–78. http://dx.doi.org/10.1515/jee-2018-0010.
Testo completoAbstract (sommario):
Abstract With the development of the microstructure fabrication technique, microfluidic chips are widely used in biological and medical researchers. Future advances in their commercial applications depend on the mass bonding of microfluidic chip. In this study we are presenting a simple, low cost and fast way of bonding microfluidic chips at room temperature. The influence of the bonding pressure on the deformation of the microchannel and adhesive tape was analyzed by numerical simulation. By this method, the microfluidic chip can be fully sealed at low temperature and pressure without using any equipment. The dye water and gas leakage test indicated that the microfluidic chip can be bonded without leakage or block and its bonding strength can up to 0.84 MPa.
37
Zhao, Pei, Jianchun Wang, Yan Li, Xueying Wang, Chengmin Chen, and Guangxia Liu. "Microfluidic Technology for the Production of Well-Ordered Porous Polymer Scaffolds." Polymers 12, no. 9 (2020): 1863. http://dx.doi.org/10.3390/polym12091863.
Testo completoAbstract (sommario):
Advances in tissue engineering (TE) have revealed that porosity architectures, such as pore shape, pore size and pore interconnectivity are the key morphological properties of scaffolds. Well-ordered porous polymer scaffolds, which have uniform pore size, regular geometric shape, high porosity and good pore interconnectivity, facilitate the loading and distribution of active biomolecules, as well as cell adhesion, proliferation and migration. However, these are difficult to prepare by traditional methods and the existing well-ordered porous scaffold preparation methods require expensive experimental equipment or cumbersome preparation steps. Generally, droplet-based microfluidics, which generates and manipulates discrete droplets through immiscible multiphase flows inside microchannels, has emerged as a versatile tool for generation of well-ordered porous materials. This short review details this novel method and the latest developments in well-ordered porous scaffold preparation via microfluidic technology. The pore structure and properties of microfluidic scaffolds are discussed in depth, laying the foundation for further research and application in TE. Furthermore, we outline the bottlenecks and future developments in this particular field, and a brief outlook on the future development of microfluidic technique for scaffold fabrication is presented.
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Qiu, Jingjiang, Junfu Li, Zhongwei Guo, et al. "3D Printing of Individualized Microfluidic Chips with DLP-Based Printer." Materials 16, no. 21 (2023): 6984. http://dx.doi.org/10.3390/ma16216984.
Testo completoAbstract (sommario):
Microfluidic chips have shown their potential for applications in fields such as chemistry and biology, and 3D printing is increasingly utilized as the fabrication method for microfluidic chips. To address key issues such as the long printing time for conventional 3D printing of a single chip and the demand for rapid response in individualized microfluidic chip customization, we have optimized the use of DLP (digital light processing) technology, which offers faster printing speeds due to its surface exposure method. In this study, we specifically focused on developing a fast-manufacturing process for directly printing microfluidic chips, addressing the high cost of traditional microfabrication processes and the lengthy production times associated with other 3D printing methods for microfluidic chips. Based on the designed three-dimensional chip model, we utilized a DLP-based printer to directly print two-dimensional and three-dimensional microfluidic chips with photosensitive resin. To overcome the challenge of clogging in printing microchannels, we proposed a printing method that combined an open-channel design with transparent adhesive tape sealing. This method enables the rapid printing of microfluidic chips with complex and intricate microstructures. This research provides a crucial foundation for the development of microfluidic chips in biomedical research.
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Amoyav, Benzion, Yoel Goldstein, Eliana Steinberg, and Ofra Benny. "3D Printed Microfluidic Devices for Drug Release Assays." Pharmaceutics 13, no. 1 (2020): 13. http://dx.doi.org/10.3390/pharmaceutics13010013.
Testo completoAbstract (sommario):
Microfluidics research for various applications, including drug delivery, cell-based assays and biomedical research has grown exponentially. Despite this technology’s enormous potential, drawbacks include the need for multistep fabrication, typically with lithography. We present a one-step fabrication process of a microfluidic chip for drug dissolution assays based on a 3D printing technology. Doxorubicin porous and non-porous microspheres, with a mean diameter of 250µm, were fabricated using a conventional “batch” or microfluidic method, based on an optimized solid-in-oil-in-water protocol. Microspheres fabricated with microfluidics system exhibited higher encapsulation efficiency and drug content as compared with batch formulations. We determined drug release profiles of microspheres in varying pH conditions using two distinct dissolution devices that differed in their mechanical barrier structures. The release profile of the “V” shape barrier was similar to that of the dialysis sac test and differed from the “basket” barrier design. Importantly, a cytotoxicity test confirmed biocompatibility of the printed resin. Finally, the chip exhibited high durability and stability, enabling multiple recycling sessions. We show how the combination of microfluidics and 3D printing can reduce costs and time, providing an efficient platform for particle production while offering a feasible cost-effective alternative to clean-room facility polydimethylsiloxane-based chip microfabrication.
40
Li, Zong An, Li Ya Hou, Wei Yi Zhang, and Li Zhu. "A New Fabrication Method for Paper-Based Microfluidic Device Used in Bio-Assay." Key Engineering Materials 562-565 (July 2013): 601–7. http://dx.doi.org/10.4028/www.scientific.net/kem.562-565.601.
Testo completoAbstract (sommario):
Paper-based microfluidic devices have a significant potential for low-cost diagnostics in the developing world. This study reported a simple fabrication method based on the digitallization of microfluidic technology for paper based microfluidic devices. Melted wax was jetted steadily with PZT actuated microfluidic pulse inertia driving system and pulled-forged glass micronozzle in the form of droplets. The wax melted into filter paper to form hydrophobic wall and different patterns for paper microfluidic devices were made. The influence of system parameters such as driving force, frequency, the fabrication process and the tip diameter of glass micronozzle on the wax line width was experimentally studied. 75 μm500 μm wax lines were achieved with the wax printing system. The paper microfluidic devices fabricated could lead the capillary action of black ink and the color change reaction of NaOH and phenolphthalein solution. Result showed that the wax printing system is simple structured and this method suggests a novel path to develop simple, inexpensive, and portable diagnostic assays.
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Guo, Wenpeng, Li Tang, Biqiang Zhou, and Yingsing Fung. "Fundamental Studies of Rapidly Fabricated On-Chip Passive Micromixer for Modular Microfluidics." Micromachines 12, no. 2 (2021): 153. http://dx.doi.org/10.3390/mi12020153.
Testo completoAbstract (sommario):
Micromixers play an important role in many modular microfluidics. Complex on-chip mixing units and smooth channel surfaces ablated by lasers on polymers are well-known problems for microfluidic chip fabricating techniques. However, little is known about the ablation of rugged surfaces on polymer chips for mixing uses. This paper provides the first report of an on-chip compact micromixer simply, easily and quickly fabricated using laser-ablated irregular microspheric surfaces on a polymethyl methacrylate (PMMA) microfluidic chip for continuous mixing uses in modular microfluidics. The straight line channel geometry is designed for sequential mixing of nanoliter fluids in about 1 s. The results verify that up to about 90% of fluids can be mixed in a channel only 500 µm long, 200 µm wide and 150 µm deep using the developed micromixer fabricating method under optimized conditions. The computational flow dynamics simulation and experimental result agree well with each other.
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Yata, Vinod Kumar, Neeraj Yadav, Vibhav Katoch, et al. "Enrichment of motile spermatozoa from cattle semen samples by microfluidics method." Indian Journal of Animal Sciences 92, no. 6 (2022): 711–16. http://dx.doi.org/10.56093/ijans.v92i6.114553.
Testo completoAbstract (sommario):
Motile sperm cell separation is important in sample preparation for both artificial insemination and cryopreservation of semen. A novel microfluidic device consisting of an inlet microchannel, a separating reservoir and two outlet microchannels was developed to enrich the motile sperm cells of cattle semen samples. Sperm separation was performed in this microfluidic device using a continuous flow process based on the swim up behaviour of motile cells. Separating reservoir allows the high motile sperm cells to swim up and pass through the top outlet of the reservoir. Low and non-motile sperm cells pass through the bottom outlet of the reservoir in the direction of fluid flow. The microfluidic device was fabricated using polydimethylsiloxane (PDMS) and semen samples were infused into the microfluidic device through a syringe pump. Sperm motility was analyzed by Computer-assisted sperm analysis (CASA). More than 80% enrichment of motile spermatozoa in the cattle semen samples was observed after their separation in the fabricated microfluidic device.
43
Zhang, Naiyin, Zhenya Liu, and Junchao Wang. "Machine-Learning-Enabled Design and Manipulation of a Microfluidic Concentration Gradient Generator." Micromachines 13, no. 11 (2022): 1810. http://dx.doi.org/10.3390/mi13111810.
Testo completoAbstract (sommario):
Microfluidics concentration gradient generators have been widely applied in chemical and biological fields. However, the current gradient generators still have some limitations. In this work, we presented a microfluidic concentration gradient generator with its corresponding manipulation process to generate an arbitrary concentration gradient. Machine-learning techniques and interpolation algorithms were implemented to help researchers instantly analyze the current concentration profile of the gradient generator with different inlet configurations. The proposed method has a 93.71% accuracy rate with a 300× acceleration effect compared to the conventional finite element analysis. In addition, our method shows the potential application of the design automation and computer-aided design of microfluidics by leveraging both artificial neural networks and computer science algorithms.
44
Hamidovic, Medina, and Ferenc Ender. "A Novel Method for Fabricating Microfluidic Devices Containing Immobilized Biological Specimens." Periodica Polytechnica Electrical Engineering and Computer Science 63, no. 2 (2019): 85–93. http://dx.doi.org/10.3311/ppee.13523.
Testo completoAbstract (sommario):
Microfluidic devices are dominantly fabricated using the soft lithography microfabrication techniques and polydimethylsiloxane (PDMS) as a structural material. Although the technique is applicable for the majority of microfluidic devices, it has limited use for the fabrication of microfluidic devices with immobilized biological specimen due to the low biocompatibility- a consequence of the plasma-assisted bonding step during the assembly of the final device. In this step, biological specimens within the microfluidic device are affected by strong plasma exposure which ultimately can degrade their biochemical activity and stability. To the best of our knowledge, this paper presents for the first time a method for increasing the biocompatibility of a conventional PDMS soft lithography process and enables fabrication of the microfluidic devices containing immobilized biological specimens. Protection of the biological specimen during the plasma bonding step is ensured by placing a protective Polyvinyl Alcohol (PVA) nanofiber layer over the biological specimens. The method is verified against the conventional soft lithography method by fabricating microfluidic devices containing enzyme-filled microreactors and following enzymatic reactions. It was shown that inadvantageous impact of the plasma is reduced by utilizing a protective PVA layer which ultimately preserves the specific activity and biochemical stability of the immobilized enzymes.
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Wei, Xiaohao, and Liqiu Wang. "Microfluidic Method for Synthesizing Cu2O Nanofluids." Journal of Thermophysics and Heat Transfer 24, no. 2 (2010): 445–48. http://dx.doi.org/10.2514/1.48984.
Testo completo
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Jiang, Hai, Xuan Weng, and Dongqing Li. "A novel microfluidic flow focusing method." Biomicrofluidics 8, no. 5 (2014): 054120. http://dx.doi.org/10.1063/1.4899807.
Testo completo
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Ješeta, Michal, Kateřina Franzová, Jana Žáková, Pavel Ventruba, and Igor Crha. "Comparison of microfluidic and swim-up sperm separation methods for IVF." Medical Journal of Cell Biology 8, no. 4 (2020): 170–75. http://dx.doi.org/10.2478/acb-2020-0022.
Testo completoAbstract (sommario):
Abstract Sperm separation for ICSI is an essential step in realization of the IVF procedures. The method of microfluidic separation of sperm cells using chips has been applied more and more frequently in recent years. This method is often presented as extremely gentle to spermatozoa and decreasing significantly concentration of sperm cells with fragmented DNA when compared to conventional methods. The aim of our study was to verify a microfluidic chip system from the perspective of its potential to select spermatozoa with non-fragmented DNA. We tested the efficiency of this separation method against the swim-up method. In this study we evaluated sperm DNA integrity before and after the separation methods in ten patients. Ejaculate of each patient was separated by both the swim up method and the microfluidic chip method at the same time. It was shown that both the methods are very similar in reduction of spermatozoa with fragmented DNA. Interestingly, the concentration of spermatozoa with fragmented DNA was lower after the microfluidic separation than after the swim-up method in all the patients. Nevertheless, the differences were not statistically significant with only 2.1% on average, which is negligible in terms of practical use. Running title: Microfluidic chip and DNA fragmentation
48
Mesquita, Pedro, Liyuan Gong, and Yang Lin. "A Low-Cost Microfluidic Method for Microplastics Identification: Towards Continuous Recognition." Micromachines 13, no. 4 (2022): 499. http://dx.doi.org/10.3390/mi13040499.
Testo completoAbstract (sommario):
Plastic pollution has emerged as a growing concern worldwide. In particular, the most abundant plastic debris, microplastics, has necessitated the development of rapid and effective identification methods to track down the stages and evidence of the pollution. In this paper, we combine low-cost plastic staining technologies using Nile Red with the continuous feature offered by microfluidics to propose a low-cost 3D printed device for the identification of microplastics. It is observed that the microfluidic devices indicate comparable staining and identification performance compared to conventional Nile Red staining processes while offering the advantages of continuous recognition for long-term environmental monitoring. The results also show that concentration, temperature, and residency time possess strong effects on the identification performance. Finally, various microplastics have been applied to further demonstrate the effectiveness of the proposed devices. It is found that, among different types of microplastics, non-spherical microplastics show the maximal fluorescence level. Meanwhile, natural fibers indicate better staining quality when compared to synthetic ones.
49
Zhang, Chunsun, and Da Xing. "Microfluidic gradient PCR (MG-PCR): a new method for microfluidic DNA amplification." Biomedical Microdevices 12, no. 1 (2009): 1–12. http://dx.doi.org/10.1007/s10544-009-9352-2.
Testo completo
50
Liu, Zhe, Xiaojie Ma, Yanzheng Ge, et al. "Preparation and Regulation of Natural Amphiphilic Zein Nanoparticles by Microfluidic Technology." Foods 13, no. 11 (2024): 1730. http://dx.doi.org/10.3390/foods13111730.
Testo completoAbstract (sommario):
Microfluidic technology, as a continuous and mass preparation method of nanoparticles, has attracted much attention in recent years. In this study, zein nanoparticles (ZNPs) were continuously fabricated in a highly controlled manner by combining a microfluidics platform with the antisolvent method. The impact of ethanol content (60~95%, v/v) and flow rates of inner and outer phases in the microfluidics platform on particle properties were examined. Among all ZNPS, 90%-ZNPs have the highest solubility (32.83%) and the lowest hydrophobicity (90.43), which is the reverse point of the hydrophobicity of ZNPs. Moreover, when the inner phase flow rate was 1.5 mL/h, the particle size decreased significantly from 182.81 nm to 133.13 nm as the outer phase flow rate increased from 10 mL/h to 50 mL/h. The results revealed that ethanol content had significant impacts on hydrophilic–hydrophobic properties of ZNPs. The flow rates of ethanol–water solutions and deionized water (solvent and antisolvent) in the microfluidics platform significantly affected the particle size of ZNPs. These findings demonstrated that the combined application of a microfluidics platform and an antisolvent method could be an effective pathway for precisely controlling the fabrication process of protein nanoparticles and modulating their physicochemical properties.