Showing papers on "Microfluidics published in 2022"
TL;DR: A review of the fluid dynamics of inkjet printing can be found in this paper , where the main challenges for present and future research are discussed both on the printhead side and on the receiving substrate side.
Abstract: Inkjet printing is the most widespread technological application of microfluidics. It is characterized by its high drop productivity, small volumes, and extreme reproducibility. This review gives a synopsis of the fluid dynamics of inkjet printing and discusses the main challenges for present and future research. These lie both on the printhead side—namely, the detailed flow inside the printhead, entrained bubbles, the meniscus dynamics, wetting phenomena at the nozzle plate, and jet formation—and on the receiving substrate side—namely, droplet impact, merging, wetting of the substrate, droplet evaporation, and drying. In most cases the droplets are multicomponent, displaying rich physicochemical hydrodynamic phenomena. The challenges on the printhead side and on the receiving substrate side are interwoven, as optimizing the process and the materials with respect to either side alone is not enough: As the same ink (or other jetted liquid) is used and as droplet frequency and size matter on both sides, the process must be optimized as a whole.
108 citations
TL;DR: This study introduces the volumetric bioprinting of complex organoid‐laden constructs, which capture key functions of the human liver and opens up new possibilities for regenerative medicine and personalized drug testing.
Abstract: Organ‐ and tissue‐level biological functions are intimately linked to microscale cell–cell interactions and to the overarching tissue architecture. Together, biofabrication and organoid technologies offer the unique potential to engineer multi‐scale living constructs, with cellular microenvironments formed by stem cell self‐assembled structures embedded in customizable bioprinted geometries. This study introduces the volumetric bioprinting of complex organoid‐laden constructs, which capture key functions of the human liver. Volumetric bioprinting via optical tomography shapes organoid‐laden gelatin hydrogels into complex centimeter‐scale 3D structures in under 20 s. Optically tuned bioresins enable refractive index matching of specific intracellular structures, countering the disruptive impact of cell‐mediated light scattering on printing resolution. This layerless, nozzle‐free technique poses no harmful mechanical stresses on organoids, resulting in superior viability and morphology preservation post‐printing. Bioprinted organoids undergo hepatocytic differentiation showing albumin synthesis, liver‐specific enzyme activity, and remarkably acquired native‐like polarization. Organoids embedded within low stiffness gelatins (<2 kPa) are bioprinted into mathematically defined lattices with varying degrees of pore network tortuosity, and cultured under perfusion. These structures act as metabolic biofactories in which liver‐specific ammonia detoxification can be enhanced by the architectural profile of the constructs. This technology opens up new possibilities for regenerative medicine and personalized drug testing.
70 citations
TL;DR: In this article , a chip-DIA workflow was proposed to profile the proteomes of adherent and non-adherent malignant cells, with good reproducibility and <16% missing values between runs.
Abstract: Single-cell proteomics can reveal cellular phenotypic heterogeneity and cell-specific functional networks underlying biological processes. Here, we present a streamlined workflow combining microfluidic chips for all-in-one proteomic sample preparation and data-independent acquisition (DIA) mass spectrometry (MS) for proteomic analysis down to the single-cell level. The proteomics chips enable multiplexed and automated cell isolation/counting/imaging and sample processing in a single device. Combining chip-based sample handling with DIA-MS using project-specific mass spectral libraries, we profile on average ~1,500 protein groups across 20 single mammalian cells. Applying the chip-DIA workflow to profile the proteomes of adherent and non-adherent malignant cells, we cover a dynamic range of 5 orders of magnitude with good reproducibility and <16% missing values between runs. Taken together, the chip-DIA workflow offers all-in-one cell characterization, analytical sensitivity and robustness, and the option to add additional functionalities in the future, thus providing a basis for advanced single-cell proteomics applications.
64 citations
TL;DR: In this paper , a chip-DIA workflow was proposed to profile the proteomes of adherent and non-adherent malignant cells, with good reproducibility and <16% missing values between runs.
Abstract: Single-cell proteomics can reveal cellular phenotypic heterogeneity and cell-specific functional networks underlying biological processes. Here, we present a streamlined workflow combining microfluidic chips for all-in-one proteomic sample preparation and data-independent acquisition (DIA) mass spectrometry (MS) for proteomic analysis down to the single-cell level. The proteomics chips enable multiplexed and automated cell isolation/counting/imaging and sample processing in a single device. Combining chip-based sample handling with DIA-MS using project-specific mass spectral libraries, we profile on average ~1,500 protein groups across 20 single mammalian cells. Applying the chip-DIA workflow to profile the proteomes of adherent and non-adherent malignant cells, we cover a dynamic range of 5 orders of magnitude with good reproducibility and <16% missing values between runs. Taken together, the chip-DIA workflow offers all-in-one cell characterization, analytical sensitivity and robustness, and the option to add additional functionalities in the future, thus providing a basis for advanced single-cell proteomics applications.
58 citations
TL;DR: This perspective considers ways in which the field of microfluidics can increase its impact by improving existing technologies and enabling new functionalities, and identifies outstanding technical challenges whose resolution could increase the accessibility of micro fluidics to users with both scientific and non-technical backgrounds.
Abstract: This perspective considers ways in which the field of microfluidics can increase its impact by improving existing technologies and enabling new functionalities. We highlight applications where microfluidics has made or can make important contributions, including diagnostics, food safety, and the production of materials. The success of microfluidics assumes several forms, including fundamental innovations in fluid mechanics that enable the precise manipulation of fluids at small scales and the development of portable microfluidic chips for commercial purposes. We identify outstanding technical challenges whose resolution could increase the accessibility of microfluidics to users with both scientific and non-technical backgrounds. They include the simplification of procedures for sample preparation, the identification of materials for the production of microfluidic devices in both laboratory and commercial settings, and the replacement of auxiliary equipment with automated components for the operation of microfluidic devices.
56 citations
TL;DR: A wearable plasmonic paper–based microfluidic system for continuous and simultaneous quantitative analysis of sweat loss, sweat rate, and metabolites in sweat is introduced and the sensitive detection and quantification of uric acid in sweat at physiological and pathological concentrations is demonstrated.
Abstract: Wearable sweat sensors have the potential to provide clinically meaningful information associated with the health and disease states of individuals. Current sensors mainly rely on enzymes and antibodies as biorecognition elements to achieve specific quantification of metabolite and stress biomarkers in sweat. However, enzymes and antibodies are prone to degrade over time, compromising the sensor performance. Here, we introduce a wearable plasmonic paper–based microfluidic system for continuous and simultaneous quantitative analysis of sweat loss, sweat rate, and metabolites in sweat. Plasmonic sensors based on label-free surface-enhanced Raman spectroscopy (SERS) can provide chemical “fingerprint” information for analyte identification. We demonstrate the sensitive detection and quantification of uric acid in sweat at physiological and pathological concentrations. The well-defined flow characteristics of paper microfluidic devices enable accurate quantification of sweat loss and sweat rate. The wearable plasmonic device is soft, flexible, and stretchable, which can robustly interface with the skin without inducing chemical or physical irritation.
53 citations
TL;DR: Anisotropic hydrogels have been receiving considerable attention in recent years because they display superior and new functionalities that their isotropic counterparts fail to exhibit as discussed by the authors , which makes them promising candidates for applications in various fields, such as tissue engineering, cell control, artificial implants, drug delivery, microfluidics, smart actuators and sensors, soft robotics, flexible electronics, and gel electrolytes for supercapacitors.
51 citations
TL;DR: After application and evaluation in different environmental and body fluid matrices, this sensor and the detection method have proved to be a label-free, real-time, easy-to-operate, and specific strategy for SARS-CoV-2 screening and diagnosis.
Abstract: The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has lasted for almost 2 years. Stemming its spread has posed severe challenges for clinical virus detection. A long turnaround time, complicated operation, and low accuracy have become bottlenecks in developing detection techniques. Adopting a direct antigen detection strategy, we developed a fast-responding and quantitative capacitive aptasensor for ultratrace nucleocapsid protein detection based on a low-cost microelectrode array (MEA) chip. Employing the solid–liquid interface capacitance with a sensitivity of picofarad level, the tiny change on the MEA surface can be definitively detected. As a result, the limit of detection reaches an ultralow level of femtogram per milliliter in different matrices. Integrated with efficient microfluidic enrichment, the response time of this sensor from the sample to the result is shortened to 15 s, completely meeting the real-time detection demand. Moreover, the wide linear range of the sensor is from 10–5 to 10–2 ng/mL, and a high selectivity of 6369:1 is achieved. After application and evaluation in different environmental and body fluid matrices, this sensor and the detection method have proved to be a label-free, real-time, easy-to-operate, and specific strategy for SARS-CoV-2 screening and diagnosis.
46 citations
TL;DR: In this paper , a recombinase polymerase amplification (RPA)-integrated microfluidic paper-based analytical device (μPAD) was designed for supersensitive SERS detection.
45 citations
TL;DR: Micro-CAL as mentioned in this paper is a computed axial lithography (CAL) of fused silica components, by tomographically illuminating a photopolymer-silica nanocomposite that is then sintered.
Abstract: Glass is increasingly desired as a material for manufacturing complex microscopic geometries, from the micro-optics in compact consumer products to microfluidic systems for chemical synthesis and biological analyses. As the size, geometric, surface roughness, and mechanical strength requirements of glass evolve, conventional processing methods are challenged. We introduce microscale computed axial lithography (micro-CAL) of fused silica components, by tomographically illuminating a photopolymer-silica nanocomposite that is then sintered. We fabricated three-dimensional microfluidics with internal diameters of 150 micrometers, free-form micro-optical elements with a surface roughness of 6 nanometers, and complex high-strength trusses and lattice structures with minimum feature sizes of 50 micrometers. As a high-speed, layer-free digital light manufacturing process, micro-CAL can process nanocomposites with high solids content and high geometric freedom, enabling new device structures and applications.
44 citations
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TL;DR: MicroFluID as discussed by the authors is a novel RFID artifact based on a multiple-chip structure and microfluidic switches, which informs the input state by directly reading variable ID information instead of retrieving primitive signals.
Abstract: RFID has been widely used for activity and gesture recognition in emerging interaction paradigms given its low cost, lightweight, and pervasiveness. However, current learning-based approaches on RFID sensing require significant efforts in data collection, feature extraction, and model training. To save data processing effort, we present MicroFluID, a novel RFID artifact based on a multiple-chip structure and microfluidic switches, which informs the input state by directly reading variable ID information instead of retrieving primitive signals. Fabricated on flexible substrates, four types of microfluidic switch circuits are designed to respond to external physical events, including pressure, bend, temperature, and gravity. By default, chips are disconnected into the circuit owing to the reserved gaps in transmission line. While external input or status change occurs, conductive liquid floating in the microfluidics channels will fill the gap(s), creating a connection to certain chip(s). In prototyping the device, we conducted a series of simulations and experiments to explore the feasibility of the multi-chip tag design, key fabrication parameters, interaction performance, and users' perceptions.
TL;DR: The microfluidic chain reaction (MCR) as mentioned in this paper is the conditional, structurally programmed propagation of capillary flow events, which can be used for point-of-care diagnostics.
Abstract: Chain reactions, characterized by initiation, propagation and termination, are stochastic at microscopic scales and underlie vital chemical (for example, combustion engines), nuclear and biotechnological (for example, polymerase chain reaction) applications1-5. At macroscopic scales, chain reactions are deterministic and limited to applications for entertainment and art such as falling dominoes and Rube Goldberg machines. On the other hand, the microfluidic lab-on-a-chip (also called a micro-total analysis system)6,7 was visualized as an integrated chip, akin to microelectronic integrated circuits, yet in practice remains dependent on cumbersome peripherals, connections and a computer for automation8-11. Capillary microfluidics integrate energy supply and flow control onto a single chip by using capillary phenomena, but programmability remains rudimentary with at most a handful (eight) operations possible12-19. Here we introduce the microfluidic chain reaction (MCR) as the conditional, structurally programmed propagation of capillary flow events. Monolithic chips integrating a MCR are three-dimensionally printed, and powered by the free energy of a paper pump, autonomously execute liquid handling algorithms step-by-step. With MCR, we automated (1) the sequential release of 300 aliquots across chained, interconnected chips, (2) a protocol for severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) antibodies detection in saliva and (3) a thrombin generation assay by continuous subsampling and analysis of coagulation-activated plasma with parallel operations including timers, iterative cycles of synchronous flow and stop-flow operations. MCRs are untethered from and unencumbered by peripherals, encode programs structurally in situ and can form a frugal, versatile, bona fide lab-on-a-chip with wide-ranging applications in liquid handling and point-of-care diagnostics.
TL;DR: In this paper , a review summarizes the conventional strategies and microfluidic-based methods for exosome isolation along with their strengths and limitations, and also introduces various commercially available platforms and kits.
TL;DR: This review is intended to call attention to the status of disease treatment in underdeveloped areas and to encourage the researchers of microfluidics to develop standards for these devices.
Abstract: The early diagnosis of infectious diseases is critical because it can greatly increase recovery rates and prevent the spread of diseases such as COVID-19; however, in many areas with insufficient medical facilities, the timely detection of diseases is challenging. Conventional medical testing methods require specialized laboratory equipment and well-trained operators, limiting the applicability of these tests. Microfluidic point-of-care (POC) equipment can rapidly detect diseases at low cost. This technology could be used to detect diseases in underdeveloped areas to reduce the effects of disease and improve quality of life in these areas. This review details microfluidic POC equipment and its applications. First, the concept of microfluidic POC devices is discussed. We then describe applications of microfluidic POC devices for infectious diseases, cardiovascular diseases, tumors (cancer), and chronic diseases, and discuss the future incorporation of microfluidic POC devices into applications such as wearable devices and telemedicine. Finally, the review concludes by analyzing the present state of the microfluidic field, and suggestions are made. This review is intended to call attention to the status of disease treatment in underdeveloped areas and to encourage the researchers of microfluidics to develop standards for these devices.
TL;DR: It is demonstrated that this light-induced charged slippery surface (LICS) exerts photocontrol of droplets with fast speed, long distance, antigravity motion, and directionally collective motion and is extended to biomedical domains, ranging from specific morphological hydrogel bead formation in an open environment to biological diagnosis and analysis in closed-channel microfluidics.
Abstract: Slippery lubricant-infused porous (SLIPS) and superhydrophobic surfaces have emerged as promising interfacial materials for various applications such as self-cleaning, anti-icing, and antifouling. Paradoxically, the coverage/screening of lubricant layer on underlying rough matrix endows functionalities impossible on superhydrophobic surfaces; however, the inherent flexibility in programming droplet manipulation through tailoring structure or surface charge gradient in underlying matrix is compromised. Here, we develop a class of slippery material that harnesses the dual advantages of both solid and lubricant. This is achieved by rationally constructing a photothermal-responsive composite matrix with real-time light-induced surface charge regeneration capability, enabling photocontrol of droplets in various working scenarios. We demonstrate that this light-induced charged slippery surface (LICS) exerts photocontrol of droplets with fast speed, long distance, antigravity motion, and directionally collective motion. We further extend the LICS to biomedical domains, ranging from specific morphological hydrogel bead formation in an open environment to biological diagnosis and analysis in closed-channel microfluidics.
TL;DR: In this paper , a microfluidic organ-on-chip platform for matrix-based, heterogeneous 3D cultures with fully integrated electrochemical chemo-and biosensor arrays for the energy metabolites oxygen, lactate, and glucose was developed.
Abstract: Three-dimensional cell cultures using patient-derived stem cells are essential in vitro models for a more efficient and individualized cancer therapy. Currently, culture conditions and metabolite concentrations, especially hypoxia, are often not accessible continuously and in situ within microphysiological systems. However, understanding and standardizing the cellular microenvironment are the key to successful in vitro models. We developed a microfluidic organ-on-chip platform for matrix-based, heterogeneous 3D cultures with fully integrated electrochemical chemo- and biosensor arrays for the energy metabolites oxygen, lactate, and glucose. Advanced microstructures allow straightforward cell matrix integration with standard laboratory equipment, compartmentalization, and microfluidic access. Single, patient-derived, triple-negative breast cancer stem cells develop into tumour organoids in a heterogeneous spheroid culture on-chip. Our system allows unprecedented control of culture conditions, including hypoxia, and simultaneous verification by integrated sensors. Beyond previous works, our results demonstrate precise and reproducible on-chip multi-analyte metabolite monitoring under dynamic conditions from a matrix-based culture over more than one week. Responses to alterations in culture conditions and cancer drug exposure, such as metabolite consumption and production rates, could be accessed quantitatively and in real-time, in contrast to endpoint analyses. Our approach highlights the importance of continuous, in situ metabolite monitoring in 3D cell cultures regarding the standardization and control of culture conditions, and drug screening in cancer research. Overall, the results underline the potential of microsensors in organ-on-chip systems for successful application, e.g. in personalized medicine.
TL;DR: In this article , an error in Figure 5c was found and this error does not affect the results or conclusions of the paper, nor does it affect the accuracy of the analysis.
Abstract: Adv. Funct. Mater. 2021, 2105190. DOI: 10.1002/adfm.202105190 The originally published version of this article contains an error in Figure 5c. This error does not affect the results or conclusions of the paper. The corrected Figure 5 is reproduced below. The authors apologize for any inconvenience this may have caused.
TL;DR: In this article , the authors reviewed the bio-recognition elements integrated on microfluidic chips in recent years and the progress of micro-device development for pathogen pretreatment.
Abstract: Foodborne diseases caused by pathogenic bacteria pose a serious threat to human health. Early and rapid detection of foodborne pathogens is an urgent task for preventing disease outbreaks. Microfluidic devices are simple, automatic, and portable miniaturized systems. Compared with traditional techniques, microfluidic devices have attracted much attention because of their high efficiency and convenience in the concentration and detection of foodborne pathogens. This article firstly reviews the bio-recognition elements integrated on microfluidic chips in recent years and the progress of microfluidic chip development for pathogen pretreatment. Furthermore, the research progress of microfluidic technology based on optical and electrochemical sensors for the detection of foodborne pathogenic bacteria is summarized and discussed. Finally, the future prospects for the application and challenges of microfluidic chips based on biosensors are presented.
TL;DR: In this article , an ultrasound-sensitive optofluidic biosensor with interface whispering gallery modes in a microbubble cavity is presented, which can achieve a detection limit as low as 0.3 pg/cm2.
Abstract: Significance Optical microresonators have emerged as promising platforms for label-free detection of molecules. However, approaching optimum sensitivity is hindered due to the weak tail of evanescent fields. Here, we report the implementation of the interface modes for ultrasensitive sensing in a microbubble resonator. With the electromagnetic field peaked at the interface between the optical resonator and the analyte solution, interface modes enable sensing of biomolecules with a detection limit of 0.3 pg/cm2. Single-molecule detection is further demonstrated using the plasmonic-enhanced interface modes. In addition, intrinsically integrated into a microfluidic channel, the sensor exhibits ultrasmall sample consumption down to 10 pL, providing an automatic platform for biomedical analysis. Label-free sensors are highly desirable for biological analysis and early-stage disease diagnosis. Optical evanescent sensors have shown extraordinary ability in label-free detection, but their potentials have not been fully exploited because of the weak evanescent field tails at the sensing surfaces. Here, we report an ultrasensitive optofluidic biosensor with interface whispering gallery modes in a microbubble cavity. The interface modes feature both the peak of electromagnetic-field intensity at the sensing surface and high-Q factors even in a small-sized cavity, enabling a detection limit as low as 0.3 pg/cm2. The sample consumption can be pushed down to 10 pL due to the intrinsically integrated microfluidic channel. Furthermore, detection of single DNA with 8 kDa molecular weight is realized by the plasmonic-enhanced interface mode.
TL;DR: In this article , the authors present a review of the best practices in the field of microfluidic energy conversion for the past 20 years and present opportunities for future research directions and technology advances.
Abstract: Electrochemical energy conversion is an important supplement for storage and on-demand use of renewable energy. In this regard, microfluidics offers prospects to raise the efficiency and rate of electrochemical energy conversion through enhanced mass transport, flexible cell design, and ability to eliminate the physical ion-exchange membrane, an essential yet costly element in conventional electrochemical cells. Since the 2002 invention of the microfluidic fuel cell, the research field of microfluidics for electrochemical energy conversion has expanded into a great variety of cell designs, fabrication techniques, and device functions with a wide range of utility and applications. The present review aims to comprehensively synthesize the best practices in this field over the past 20 years. The underlying fundamentals and research methods are first summarized, followed by a complete assessment of all research contributions wherein microfluidics was proactively utilized to facilitate energy conversion in conjunction with electrochemical cells, such as fuel cells, flow batteries, electrolysis cells, hybrid cells, and photoelectrochemical cells. Moreover, emerging technologies and analytical tools enabled by microfluidics are also discussed. Lastly, opportunities for future research directions and technology advances are proposed.
TL;DR: A critical review of recent progress in microfluidic NPs for drug delivery with a focus on the synthesis of organic NPs usingmicrofluidics and their applications in making popular and clinically relevant NPs.
Abstract: Nanoparticles (NPs) have attracted tremendous interest in drug delivery in the past decades. Microfluidics offers a promising strategy for making NPs for drug delivery due to its capability in precisely controlling NP properties. The recent success of mRNA vaccines using microfluidics represents a big milestone for microfluidic NPs for pharmaceutical applications, and its rapid scaling up demonstrates the feasibility of using microfluidics for industrial-scale manufacturing. This article provides a critical review of recent progress in microfluidic NPs for drug delivery. First, the synthesis of organic NPs using microfluidics focusing on typical microfluidic methods and their applications in making popular and clinically relevant NPs, such as liposomes, lipid NPs, and polymer NPs, as well as their synthesis mechanisms are summarized. Then, the microfluidic synthesis of several representative inorganic NPs (e.g., silica, metal, metal oxide, and quantum dots), and hybrid NPs is discussed. Lastly, the applications of microfluidic NPs for various drug delivery applications are presented.
TL;DR: In this paper , a review of the frontiers of microfluidic platforms is carried out towards advancements in the micro-fluidics capabilities for the new-edge biomedical applications.
Abstract: The attention in lab-on-a-chip devices with their potent application in medical engineering has prolonged swiftly over the last ten years. Travelling through the technology development, innovative microfluidics devices shown enormous potential to lift the lab-on-a-chip biomedical research in traditions that are not imaginable using conventional techniques. The advances in the arena of microfluidics have prompted high-tech uprisings in numerous biomedical disciplines, including diagnostics, single-cell analysis, micro- and nano device fabrication, organ-in-chip platforms, and med-tech applications. The speedy development is motivated by the cumulative cooperation among central nanomaterials advances and innovative microfluidic aptitudes in the range of biomedical applications. Microfluidic gadgets presently undertake a significant part in numerous organic, synthetic, and designing applications, that have multiple approaches to create the vital channel and highlight measurements. In this review, the critical assessments on the frontiers of microfluidic platforms are carried out towards advancements in the microfluidic capabilities for the new-edge biomedical applications. It has been exhibited that microfluidics offers a scope of benefits contrasted with customary strategies, including further developed controllability and consistency specified by nanomaterial attributes. Herein, authors have discussed how innumerable nanomaterials empower the manufacture of microfluidic systems with advanced optical, mechanical, electrical chemical, and bio-interfacial properties ranging from the basics of microfluidics, various factors, types, and fabrication procedure to biomedical applications. A comprehensive investigation in the state-of-the-art usage of microfluidics in biomedical field is steered exemplarily to understand the significant advantages. Moreover, our assessment provides an interdisciplinary overview of modern microfabrication strategies that can be adopted for academic and industrial interests. • Herein, the frontiers of microfluidic platforms have been summarized. • Various applications of microfluidic in biomedical engineering has been discussed. • Assessed the role of nanomaterials to empower the manufacture of microfluidics. • Utility of microfabrication strategies for industrial purposes has been discussed. • Strategies to bridging gap between microfluidics and end-user has been summarized.
TL;DR: In this article , advances in the detection of pathogenic bacteria using microfluidic biosensors were discussed, and key applications of microfluidity-based rapid bacteria detection were presented.
TL;DR: A broad overview of a wide range of microfluidic chips, including the magnetic nanomaterial-based assay, metal-naphase-based approach, carbon-nanophase based approach, quantum dot-based method, and upconversion nanoparticle-based one, can be found in this article .
Abstract: Rapid, efficient, and accurate detection of foodborne bacteria is important for public health and food safety; however, point-of-care testing remains a limiting factor in the field. Compared with traditional methods, the use of microfluidic chips in monitoring foodborne bacteria has the advantages of miniaturization, automation, integration, high throughput, and low consumption. Notably, the combination of nanomaterials with microfluidics further provides an improved method of pathogen detection with superior, rapid, and sensitive detection efficiencies. This review presents a broad overview of a wide range of microfluidic chips, including the magnetic nanomaterial-based assay, metal nanomaterial-based assay, carbon nanomaterial-based assay, quantum dot-based assay, and upconversion nanoparticle-based assay, for the detection of foodborne bacteria using different nanomaterials. Additionally, the main challenges that exist for translation of scientific research into product development are discussed. On this basis, we provide perspectives on both future technological directions and potential applications, which will guide researchers in identifying the most promising areas of development in this field.
TL;DR: In this paper , a review of microfluidic devices to determine the equilibrium and dynamic interfacial tension during droplet formation, and to investigate the coalescence stability of dispersed droplets applicable to the processing and storage of emulsions, are discussed.
TL;DR: In this paper , the authors visualize the bacteria and CaCO3 distributions at the quiescent state through microfluidic chip tests where the bacterial solution (BS) and cementation solution (CS) were initially injected simultaneously from two separate microchannels and subsequently converged in a reaction microchannel.
Abstract: A significant pressing issue in microbially induced calcium carbonate precipitation (MICP) is the characterization of the heterogeneous growth mechanics of calcium carbonate (CaCO3) crystals. This study aimed to visualize the bacteria and CaCO3 distributions at the quiescent state through microfluidic chip tests where the bacterial solution (BS) and cementation solution (CS) were initially injected simultaneously from two separate microchannels and subsequently converged in a reaction microchannel. The experiments revealed that the bacterial diffusion within the CS injection area was hindered for a high concentration of calcium chloride (CaCl2) (e.g., 0.5 M), whereas diffusion appeared homogeneous for a low concentration of CaCl2 (0.05 M). In addition, the CaCO3 distribution along the width of the reaction microchannel was more uniform for 0.05 M CaCl2 than for 0.5 M CaCl2. The microfluidic chip tests in this study provided kinetic observations of the MICP process that improved the understanding of the mechanics of bacterial diffusion and CaCO3 crystal growth and their variation with different concentrations of CaCl2.
TL;DR: In this paper , a reconfigurable magnetic liquid metal robot (MLMR) is proposed to manipulate droplets in challenging confined environments, which can accomplish cooperative manipulation of multiple droplets efficiently through on-demand self-splitting and merging.
Abstract: Droplet manipulation is crucial for diverse applications ranging from bioassay to medical diagnosis. Current magnetic-field-driven manipulation strategies are mainly based on fixed or partially tunable structures, which limits their flexibility and versatility. Here, a reconfigurable magnetic liquid metal robot (MLMR) is proposed to address these challenges. Diverse droplet manipulation behaviors including steady transport, oscillatory transport, and release can be achieved by the MLMR, and their underlying physical mechanisms are revealed. Moreover, benefiting from the magnetic-field-induced active deformability and temperature-induced phase transition characteristics, its droplet-loading capacity and shape-locking/unlocking switching can be flexibly adjusted. Because of the fluidity-based adaptive deformability, MLMR can manipulate droplets in challenging confined environments. Significantly, MLMR can accomplish cooperative manipulation of multiple droplets efficiently through on-demand self-splitting and merging. The high-performance droplet manipulation using the reconfigurable and multifunctional MLMR unfolds new potential in microfluidics, biochemistry, and other interdisciplinary fields.
TL;DR: In this article , a simple, sensitive, instrument-free, CRISPR-based diagnostics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using a self-contained microfluidic system.
TL;DR: In this paper , a multifunctional and flexible hydrogel-paper patch (HPP) was proposed for real-time monitoring of electrocardiogram (ECG) signal and biochemical signal (glucose content) in sweat during exercise.