Microfluidics and Nanofluidics最新文献

{"title":"Sustainable and optimized fabrication of microfluidic devices for electrochemical detection and monitoring of microbial biofilms","authors":"Anmol Kulshrestha,&nbsp;Pratima Gupta,&nbsp;Sanjay S. Negi","doi":"10.1007/s10404-025-02804-9","DOIUrl":"10.1007/s10404-025-02804-9","url":null,"abstract":"<div><p>In healthcare and industry, infections caused by biofilms and unwanted buildup in the environment are big problems, making it important to have affordable and easy-to-use monitoring tools. The study aims to create an affordable and eco-friendly electrochemical microfluidic device that can easily check biofilm growth without needing invasive methods, making it simpler and cheaper than traditional biosensors. The fabrication of the microfluidic device involved a resource-efficient approach, utilizing 3-D printed molds made from acrylonitrile butadiene styrene material, followed by polydimethylsiloxane casting to form the channels. Screen-printed electrodes (SPEs) were integrated into the device, and acetone washing was used for channel formation. The device performed testing with one bacterial strain (<i>Staphylococcus aureus</i>), one fungal strain (<i>Candida albicans</i>), and two real samples (clinical blood and wastewater) employing impedance methods. Additionally, the study simulated real-world conditions by utilizing clinical and wastewater samples to monitor biofilm growth. Biofilm development in the microfluidic device exhibited a sigmoidal growth pattern, with impedance increases of ~ 74.4% for <i>S. aureus</i>, 73.78% for <i>C. albicans</i>, and 82.7% and 87.34% for clinical and wastewater samples, respectively. High-resolution SEM imaging confirmed the presence of biofilms on the surface of the SPEs. The dynamic range of the device was found to be 1291.57–1811.25 ohms, with a limit of detection of 0.208 CFU/mL and a sensitivity of 10.83 µA/CFU/mL. The device's sustainable fabrication process and reliable performance make it a practical option for researchers with limited resources, offering a valuable alternative to traditional biofilm study methods.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":706,"journal":{"name":"Microfluidics and Nanofluidics","volume":"29 6","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143949683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the viscous flow through a porous-walled pipe: asymptotic MHD effects","authors":"Mustafa Turkyilmazoglu,&nbsp;Abdulaziz Alotaibi","doi":"10.1007/s10404-025-02808-5","DOIUrl":"10.1007/s10404-025-02808-5","url":null,"abstract":"<div><p>This study explores the filtration problem of Newtonian, incompressible, and viscous two-dimensional fluid flow through a permeable-walled tube. The generated pressure-driven flow incorporates Darcy’s law at the circular pipe wall. We then apply a transverse magnetic field of uniform strength to control the fluid filtration. Subsequently, we analytically examine the potential impacts of the magnetic field on the magnetohydrodynamic behavior of the fluid particles and the axial pressure field using perturbation analysis. Our results delineate the characteristics of the Lorentz force on the flow and pressure field within the porous-walled pipe. Notably, the magnetically affected pressure changes sign at a specific downstream location within the pipe, while the axial velocity flattens with increasing Hartman number at the inlet. Although the inlet regime is under the well-recognized damping dominance of the magnetic field, the filtration process downstream is accelerated with the assist of it.</p></div>","PeriodicalId":706,"journal":{"name":"Microfluidics and Nanofluidics","volume":"29 6","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143944386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Current advances in biocompatibility assessment for MEMS in biomedical applications","authors":"Ahmad Razin Zainal Abidin,&nbsp;Nor Syafirah Zambry,&nbsp;Fatimah Ibrahim,&nbsp;Nurshamimi Nor Rashid,&nbsp;Nurul Fauzani Jamaluddin,&nbsp;Wan Safwani Wan Kamarul Zaman","doi":"10.1007/s10404-025-02806-7","DOIUrl":"10.1007/s10404-025-02806-7","url":null,"abstract":"<div><p>Microelectromechanical systems (MEMS) have significantly advanced biomedical applications, enabling precise control in cell culture, tissue engineering, and drug delivery by creating highly controlled microenvironments that mimic biological systems. Traditional approaches to diagnostics and tissue fabrication face challenges in precision and scalability, driving interest in MEMS-based biosensors and microfluidic devices. These technologies offer high-throughput analysis and cellular manipulation, essential for developing complex three-dimensional (3D) tissue constructs. This paper reviews advancements in MEMS biocompatibility assessment over the past 14 years (2011–2024), focusing on material selection and device design to meet regulatory and performance standards. It also evaluates in vitro and in vivo testing methods, addressing unique challenges posed by MEMS-specific characteristics such as micro-scale structures and mixed materials. Finally, this paper highlights future directions for enhancing biocompatibility, safety, and performance, paving the way for the integration of MEMS into clinical applications to address critical challenges in biomedical fields.</p></div>","PeriodicalId":706,"journal":{"name":"Microfluidics and Nanofluidics","volume":"29 6","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pore-scale method for instantaneous assessment of total permeability including the pore geometry effect in microfluidic porous networks through the use of an analogous electrical circuit","authors":"Najeeb Anjum Soomro","doi":"10.1007/s10404-025-02805-8","DOIUrl":"10.1007/s10404-025-02805-8","url":null,"abstract":"<div><p>Permeability estimation is crucial for providing fundamental information isrequired to establish production and injection rates. Several experimental and numerical approaches have been developed to evaluate the permeability of rock reservoirs at large scales (core-, reservoir-, and field- scales). However, the evaluation of the permeability at the micro-scale has remained a challenge due to the small length scale, variety and complexity of the porous structure of the microfluidic devices. Increasing usage of microfluidic devices in the petroleum field to visualize the pore events and evaluate enhanced oil recovery (EOR) techniques necessitates characterization of permeability at the pore scale. Herein, by the combination of an integrated microfluidic set-up and the analogous electrical circuit, we upgraded the conventional methods to provide an accurate, reproducible, and practical on-chip approach to the real-time absolute permeability of pore networks. Based on the designed fluidic set-up, a sequential flow rate stepping scheme was optimized and used to estimate the permeability of the porous networks after thoroughly saturating them with a fluorescein solution that was driven to the system by a pressure controller. The permeability of the micromodels was obtained by applying Darcy’s law for laminar flow after estimating the differential pressure across the whole system and the pore networks by measuring the equivalent flow resistances of the fluidic circuit. The method is highly accurate, sensitive, and effectively predicts the absolute permeability of the micromodels. The use of a pressure controller and pressure sensors affords the potential of parallelization of the microfluidic set-up and delivers high throughput compared to the previous proposed techniques. The validation of the approach was based on its independence of the porous medium geology and by providing convergent results between the experimental and computed permeability in the microfluidic devices. Moreover, this approach will help in delivering qualitative and quantitative data to understand capillary phenomena and dominant mechanisms of different chemical EOR processes at the pore scale. </p></div>","PeriodicalId":706,"journal":{"name":"Microfluidics and Nanofluidics","volume":"29 6","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143913778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microfluidic device integrated with a porous membrane for quantitative chemotaxis assay of plant-parasitic nematodes","authors":"Jing Li,&nbsp;Sinichiro Sawa,&nbsp;Isaku Kanno,&nbsp;Hirotaka Hida","doi":"10.1007/s10404-025-02807-6","DOIUrl":"10.1007/s10404-025-02807-6","url":null,"abstract":"<div><p>Plant-parasitic root-knot nematodes (RKNs) cause significant damage to plant crops by inhibiting nutrient absorption in host plants through infection. Chemotaxis is an important factor in controlling RKNs behavior as well as in understanding the mechanisms of parasitic behavior of RKNs on plants. Thus, studies on RKN chemotaxis are important for developing more environmentally friendly strategies to manage RKN infestations instead of current control methods using environmentally harmful pesticides. To better understand the chemotactic behavior of RKNs, we developed an easy-to-use microfluidic device consisting of two-layer polydimethylsiloxane (PDMS) microchannel chips and a porous hydrophilic polycarbonate membrane. The porous membrane acts both as a filter in introducing agarose gel containing nematodes to the observation chamber and as a diffuser to generate chemical concentration gradients in chemotaxis assays. We demonstrated the chemical concentration gradient was formed within 5 min in the gel-filled chamber using fluorescence substance. Using this device, we analyzed the correlation between nematode activity (chemotactic behavior and mobility) and the concentration gradients of several chemicals including KNO₃, cadaverine, and putrescine (1, 10 and 100 mM). Finally, we confirmed the repellent effect of KNO₃ and the attractive effect of cadaverine and putrescine on the RKN, <i>Meloidogyne incognita</i>, which was cultured on tomatoes, within 10 min after injecting the chemicals and quantitatively identified the correlation between nematode activity and chemical environmental conditions.</p></div>","PeriodicalId":706,"journal":{"name":"Microfluidics and Nanofluidics","volume":"29 6","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10404-025-02807-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Observing boundary layer effects on slurry electrode charging in a microfluidic electrochemical flow capacitor","authors":"Brandon Stacks,&nbsp;Haoxiang Luo,&nbsp;Deyu Li","doi":"10.1007/s10404-025-02803-w","DOIUrl":"10.1007/s10404-025-02803-w","url":null,"abstract":"<div><p>Flowable slurry electrodes play important roles in a few promising technologies for energy and water systems including electrochemical flow capacitors (EFCs) and capacitive deionization. The electrochemical performance of slurry electrodes depends on the hydrodynamic behavior of the porous particles in the slurry that serve as individual capacitors, whose dynamic interactions with the stationary electrodes and between each other are essential for spreading charges to the bulk of the slurry. So far, it has been difficult to directly observe the slurry flow and particle interactions because of the opacity of the activated carbon, a typical particle material in slurries. We previously reported a microfluidic electrochemical flow capacitor (µ-EFC), which is made of transparent materials and allows for simultaneous electrochemical characterization and optical observation of slurry electrodes under continuous flow conditions. However, the placement of the stationary Indium Tin Oxide (ITO) electrodes at the top and bottom of the µ-EFC renders it challenging to directly observe the particle dynamics in the boundary layer of the ITO electrode. Here we report on inclusion of three-dimensional (3D) gold electrodes in the µ-EFC channels, which allows for better visualization of the particle behavior in the boundary layer of stationary electrodes. The results show unique particle behaviors as they flow along and interact with the 3D electrodes of different lengths, which have important implications to the electrochemical performance of slurry electrodes.</p></div>","PeriodicalId":706,"journal":{"name":"Microfluidics and Nanofluidics","volume":"29 5","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143856525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling, simulation, and experimental characterization of particle sedimentation inside a horizontal syringe","authors":"Maryamsadat Ghoreishi,&nbsp;Efsun Senturk,&nbsp;Gianluca Cidonio,&nbsp;Chiara Scognamiglio,&nbsp;Zita Salajková,&nbsp;Mara Riminucci,&nbsp;Alessandro Corsi,&nbsp;Giancarlo Ruocco,&nbsp;Marco Leonetti,&nbsp;Riccardo Reale","doi":"10.1007/s10404-025-02802-x","DOIUrl":"10.1007/s10404-025-02802-x","url":null,"abstract":"<div><p>Sedimentation is the settling of solid particles in a liquid medium driven by gravity. This phenomenon poses significant challenges in experimental lab-on-chip (LOC) applications, as they often involve a biological sample to be loaded inside a syringe for prolonged periods (e.g. 3D bioprinting, microfluidic cytometers). Mitigating solutions such as mechanical agitators or buffer adjustments exist, but increase the complexity and cost of the setup. In this work, we developed a model of particle sedimentation inside a horizontal syringe, which highlights the importance of several parameters: syringe radius, particle terminal velocity in the buffer, syringe outlet position, and flow-rate. The model provides a simple way to estimate the concentration half-life (<span>({t}_{1/2})</span>), i.e. the time required for the concentration to halve, which is useful during the experiment design process. The model was initially tested numerically and then validated experimentally. Additionally, the applicability of the model to predict sedimentation of biological particles was experimentally demonstrated. Lastly, the model was used to develop guidelines for the design of setups with minimized sedimentation.</p></div>","PeriodicalId":706,"journal":{"name":"Microfluidics and Nanofluidics","volume":"29 5","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10404-025-02802-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143835639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Achieving continuous focusing of particles and blood cells via AC insulator-based dielectrophoresis","authors":"Kaixin Song,&nbsp;Fengjuan Xu,&nbsp;Wei Xiao,&nbsp;Zhibin Wang,&nbsp;Xiaolin Fang,&nbsp;Donglin Cao,&nbsp;Ying Chen","doi":"10.1007/s10404-025-02799-3","DOIUrl":"10.1007/s10404-025-02799-3","url":null,"abstract":"<div><p>Insulator-based dielectrophoresis (iDEP) technology manipulates particles by creating a non-uniform electric field using insulating microchannel structures. It offers advantages such as high operability and electrode-free fabrication. However, the fluid driving and construction of non-uniform electric fields based on iDEP currently mainly relied on direct current (DC), which can easily lead to water electrolysis and the generation of a large amount of Joule heat. In this study, we used two metal tubes as electrodes to apply the AC and inlet/outlet to provide stable liquid flow based on the syringe pump, ensuring stable flow and achieving the focusing of particles and blood cells. Through numerical simulation, a ratchet structure with semicircular tooth surfaces was selected. This structure provides a more uniform distribution of high-field strength regions and can withstand higher flow rates. Subsequently, experiments were conducted to determine the focusing characteristics of particles under different conditions within this chip. Cell focusing throughout improved by nearly 3 times of magnitude compared to that of similar iDEP focusing techniques. Finally, the visualization experiment realized the defined morphology focusing of blood cells, and the optimal focusing ratio reached 7.27, and the focusing characteristics of blood cells were studied. This study is expected to promote the application of dielectrophoresis technology in clinical, biological and other aspects.</p></div>","PeriodicalId":706,"journal":{"name":"Microfluidics and Nanofluidics","volume":"29 5","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143769709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effective radius of Lucas–Washburn dynamics in periodically constricted tubes","authors":"Raul Urteaga,&nbsp;Claudio L. A. Berli","doi":"10.1007/s10404-025-02801-y","DOIUrl":"10.1007/s10404-025-02801-y","url":null,"abstract":"<div><p>Capillary imbibition in periodically constricted tubes (PCTs) plays a critical role in multiple natural and technological processes, where the control of autonomous flows is intrinsically linked to the geometric architecture of the imbibition space. Here we present analytical expressions for the effective radius (<span>(r_{eff})</span>) of PCTs with different wave shapes and analyze how geometric parameters influence the infiltration dynamics. Our analysis reveals that <span>(r_{eff})</span> is strongly dependent on the ratio of maximum to minimum radii (<span>(alpha)</span>) and, for stepped geometries, on the relative segment length proportion (<span>(gamma)</span>). Increasing <span>(alpha)</span> enhances <span>(r_{eff})</span> up to a critical value, beyond which a strong reduction is observed: for <span>(alpha &gt;&gt;)</span> 2, approximately, the infiltration velocity progressively decreases. This counterintuitive behavior arises from the interplay between hydrodynamic resistance and capillary driving forces. We evaluated the effect on different geometries, achieving different <span>(r_{eff})</span> that can be analytically predicted by closed-form expressions. The model was also validated against previously reported experimental data. These findings underline the potential of geometric design to optimize capillary-driven flows, providing a framework for tailoring PCTs to specific applications in microfluidics, porous media, and related fields.</p></div>","PeriodicalId":706,"journal":{"name":"Microfluidics and Nanofluidics","volume":"29 5","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physical and chemical transformation of crosslinked polyethylene by super-pressure microchannel liquid collision","authors":"Jiangyi Song,&nbsp;Peiyu Gou,&nbsp;Naichao Chen","doi":"10.1007/s10404-025-02800-z","DOIUrl":"10.1007/s10404-025-02800-z","url":null,"abstract":"<div><p>Recycling of thermosetting material with low energy is still a significant challenge due to their stable and strong chemical bonds existed. In this work, we proposed a super-pressure microchannel liquid collision approach that combined microchannel with super-pressure driving and liquid collision to explore the physical and chemical change of crosslinked polyethylene (XLPE), by which the large bond breaking energy can be obtained and imposed on XLPE particles. Here, a super-pressure microchannel liquid collision generator (SP-MLCG) with 300 MPa input pressure and ~600 m/s output speed was designed to obtain the promising collision energy that calculated from the required energies of breaking the crosslinked bonds in XLPE. The particle size, the surface morphology, the molecular weight, the thermal stability, and the melting properties were evaluated step-by-step by optical image, SEM, GPC, TG, and DSC. By using the SP-MCLG, the size of XLPE particles decreased to ~50 μm. Meanwhile, SP-MLCG can lead to the decrease in the proportion of chains with high molecular weight, and in turn produce the reduction of thermal stable, glass transition temperature and melting temperature of XLPE particles. Especially, melt enthalpy can decrease from −89.65 to −64.14 J·g⁻¹. Hence, our proposed technique might be regarded as a promising method that is able to achieve the recycling and reuse of XLPE due to the considerable transformation of its physical and chemical properties.</p></div>","PeriodicalId":706,"journal":{"name":"Microfluidics and Nanofluidics","volume":"29 5","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}