Development Of Microfluidic Chip Research Articles

미세유체장치 내 박테리아 세포 배양을 위한 저비용 항온·항습 배양기 개발

Advances in cell culture technology have improved the understanding of the physiological principles of cells. Recently, the development of microfluidic chips has made it possible to observe single cells in a massively parallelized and accurate manner. However, in order to maximize the availability of the microfluidic cell chip, it is essential to use an incubator that can isolate the cell culture chip from the outside while minimizing contamination and maintaining the temperature and humidity required for cell culture for a long time period. Here, we developed a thermo-hygrostat incubator consisting of an Arduino-based feedback control module for controlling a temperature and humidity complex sensor, a humidifier, and a heater. The temperature and humidity of the incubator could be actively changed according to the needs and application by simple editing control variables of Arduino coding. To demonstrate the efficiency of the device, we conducted an experiment comparing the growth of bacterial cells and obtained optimal conditions necessary for culture. In conclusion, it is expected that the newly developed thermo-hygrostat incubator can be used for a variety of purposes that require active control of temperature and humidity, as well as for long-term cultivation of bacterial cells inside a microfluidic chip.

A magnetophoretic microdevice for multi-magnetic particles separation based on size: a numerical simulation study

Due to the outstanding properties, magnetic particles have been widely used as magnetic carriers and adsorbents in a diverse range of fields, such as biomedical diagnostics, food safety, and environmental monitoring, etc. Sorting different magnetic particles from each other based on size simultaneously can be very useful in multiple targets separation. To the best of our knowledge, this research firstly proposes the arc comb structure microfluidic (ACSM) chip for multi-magnetic particles separation based on size by magnetophoresis. And the parameters affecting particle trajectory and separation efficiencies, such as flow velocity, velocity ratio of the two inlets, the remanent flux density of the magnets, and dynamic viscosity of the buffer solution, were investigated by numerical simulations in this study. Particle magnetophoresis spectrum width and general separation ratio are put forward to characterize the particles separation efficiency. Under the recommended simulation condition, six kinds of magnetic beads were separated with a general separation ratio of 0.83 using the newly designed chip. And the separation ratio of the 0.5, 1.8, 2.5, 3, 3.5 and 4.5 µm magnetic particle is 100.00%, 98.18%, 66.36%, 97.25%, 97.27% and 96.36%, respectively. This numerical simulation study provides a theoretical basis for multiple magnetic particles’ separation before experimental trials and also facilitates the utilization and development of microfluidic chips in the future.

Integrated microfluidic chip coupled to mass spectrometry: A minireview of chip pretreatment methods and applications

As the development of microfluidic chip and mass spectrometry, the coupling of chip with mass spectrometry (Chip-MS) has attracted increasing attention in analytical chemistry. As a miniaturized device, microfluidic chip possesses many advantages, such as reduced sample and reagent consumption, high integration, automation, etc. Using microfluidic chip to pretreat the sample can shorten the preparation time and improve the analysis efficiency. In addition, microfluidic chip can be combined with mass spectrometry for qualitive and quantitative detection, which can provide accurate information of targets and reduce the generation of false positive results. In this minireview, we summarized the fundamental developments of integrated microfluidic chip for sample pretreatment before sample introduced into MS, and the utilization of Chip-MS without liquid chromatography separation for cell metabolomics, elemental analysis, food analysis and other applications will be evaluated.

Scaling up the throughput of microfluidic droplet-based materials synthesis: A review of recent progress and outlook.

The last two decades have witnessed tremendous progress in the development of microfluidic chips that generate micrometer- and nanometer-scale materials. These chips allow precise control over composition, structure, and particle uniformity not achievable using conventional methods. These microfluidic-generated materials have demonstrated enormous potential for applications in medicine, agriculture, food processing, acoustic, and optical meta-materials, and more. However, because the basis of these chips' performance is their precise control of fluid flows at the micrometer scale, their operation is limited to the inherently low throughputs dictated by the physics of multiphasic flows in micro-channels. This limitation on throughput results in material production rates that are too low for most practical applications. In recent years, however, significant progress has been made to tackle this challenge by designing microchip architectures that incorporate multiple microfluidic devices onto single chips. These devices can be operated in parallel to increase throughput while retaining the benefits of microfluidic particle generation. In this review, we will highlight recent work in this area and share our perspective on the key unsolved challenges and opportunities in this field.

Concentration Gradient Constructions Using Inertial Microfluidics for Studying Tumor Cell-Drug Interactions.

With the continuous development of cancer therapy, conventional animal models have exposed a series of shortcomings such as ethical issues, being time consuming and having an expensive cost. As an alternative method, microfluidic devices have shown advantages in drug screening, which can effectively shorten experimental time, reduce costs, improve efficiency, and achieve a large-scale, high-throughput and accurate analysis. However, most of these microfluidic technologies are established for narrow-range drug-concentration screening based on sensitive but limited flow rates. More simple, easy-to operate and wide-ranging concentration-gradient constructions for studying tumor cell–drug interactions in real-time have remained largely out of reach. Here, we proposed a simple and compact device that can quickly construct efficient and reliable drug-concentration gradients with a wide range of flow rates. The dynamic study of concentration-gradient formation based on successive spiral mixer regulations was investigated systematically and quantitatively. Accurate, stable, and controllable dual drug-concentration gradients were produced to evaluate simultaneously the efficacy of the anticancer drug against two tumor cell lines (human breast adenocarcinoma cells and human cervical carcinoma cells). Results showed that paclitaxel had dose-dependent effects on the two tumor cell lines under the same conditions, respectively. We expect this device to contribute to the development of microfluidic chips as a portable and economical product in terms of the potential of concentration gradient-related biochemical research.

A Microparticle Image Velocimetry Based on Light Field Imaging

Accurate 3D flow characterization in a microchannel is becoming increasingly important for the design and development of microfluidic chips. In recent years, a light held camera that can simultaneously record the direction and position information of rays in a single photographic exposure has been developed and employed in the held of computer graphics. In this paper, a microparticle image velocimetry based on light held imaging (light held μPIV) is proposed to reconstruct the 3D velocity held of a microscale flow. Both simulations and experiments are performed to verify the proposed method. The light held image of tracer particles and the point spread function (PSF) of a light held microscopic imaging system are numerically calculated based on the Abbe imaging principle. The 3D positions of the tracer particles in a flow held are then reconstructed by the Lucy-Richardson 3D deconvolution algorithm. Furthermore, a light held μPIV system based on an assembled cage light held camera with a microscope is developed, and calibrations are performed to obtain the geometric parameters of the μPIV system accurately. The simulation and experimental results demonstrate the feasibility of the proposed light held μPIV. Compared with the synthetic refocusing reconstruction method, the Lucy-Richardson 3D deconvolution algorithm greatly improves the lateral and the axial resolutions of the flow held.

On‐chip laser processing for the development of multifunctional microfluidic chips

AbstractIn the development of microfluidic chips, conventional 2D processing technologies contribute to the manufacturing of basic microchannel networks. Nevertheless, in the pursuit of versatile microfluidic chips, flexible integration of multifunctional components within a tiny chip is still challenging because a chip containing micro‐channels is a non‐flat substrate. Recently, on‐chip laser processing (OCLP) technology has emerged as an appealing alternative to achieve chip functionalization through in situ fabrication of 3D microstructures. Here, the recent development of OCLP‐enabled multifunctional microfluidic chips, including several accessible photochemical/photophysical schemes, and photosensitive materials permiting OCLP, is reviewed. To demonstrate the capability of OCLP technology, a series of typical micro‐components fabricated using OCLP are introduced. The prospects and current challenges of this field are discussed. image

Tuning the chemiluminescence of a luminol flow using plasmonic nanoparticles.

We have discovered a strong increase in the intensity of the chemiluminescence of a luminol flow and a dramatic modification of its spectral shape in the presence of metallic nanoparticles. We observed that pumping gold and silver nanoparticles into a microfluidic device fabricated in polydimethylsiloxane prolongs the glow time of luminol. We have demonstrated that the intensity of chemiluminescence in the presence of nanospheres depends on the position along the microfluidic serpentine channel. We show that the enhancement factors can be controlled by the nanoparticle size and material. Spectrally, the emission peak of luminol overlaps with the absorption band of the nanospheres, which maximizes the effect of confined plasmons on the optical density of states in the vicinity of the luminol emission peak. These observations, interpreted in terms of the Purcell effect mediated by nano-plasmons, form an essential step toward the development of microfluidic chips with gain media. Practical implementation of the discovered effect will include improving the detection limits of chemiluminescence for forensic science, research in biology and chemistry, and a number of commercial applications.