NANO LETTERS
·
2020
·
IF 11.238
Rui Feng,Qixiang Wang,Yiming Qiao,Runheng Yang,Shun An,Fanchen Meng,Shengtao Yu,Wei Hao,Benwei Fu,Peng Tao,Kehang Cui,Chengyi Song,Wen Shang,Tao Deng
A simple, fast, and contactless alternative for the generation of nanodroplets in solution is to apply light to stimulate their formation at a surface. In this work, a light-driven mechanism for the generation of nanodroplets is demonstrated by using a porous membrane. The membrane is placed at the interface between oil and water during the nanodroplet generation process. As light illuminates the membrane a photothermal conversion process induces the growth and release of water vapor bubbles into the aqueous phase. This release leads to the fluctuation of local pressure around the pores and enables the generation of oil nanodroplets. A computational simulation of the fluid dynamics provides insight into the underlying mechanism and the extent to which it is possible to increase nanodroplet concentrations. The ability to form nanodroplets in solutions without the need for mechanical moving parts is significant for the diverse biomedical and chemical applications of these materials.
研究领域:
材料科学
·
生物医学工程
·
流体力学
✓ 已验证
DOI
高影响因子
Symmetry-Basel
·
2025
·Vol. 17
·期 6
·826
·
IF 2.2
Linkai Yu,Qingyang Feng,Yifan Chen,Yongji Wu,Haizhen Sun,Hao Yang,Lining Sun
Concentration gradient generation plays a pivotal role in advancing applications across drug screening, chemical synthesis, and biomolecular studies, yet conventional methods remain constrained by labor-intensive workflows, limited throughput, and inflexible gradient control. This study presents a novel multilayer microfluidic chip leveraging shear flow-driven partitioning–recombination mechanisms to enable the flexible and high-throughput generation of concentration gradient droplets. The chip integrates interactive upper and lower polydimethylsiloxane (PDMS) layers, where sequential fluid distribution and recombination are achieved through circular and radial channels while shear forces from the oil phase induce droplet formation. Numerical simulations validated the dynamic pressure-driven concentration gradient formation, demonstrating linear gradient profiles across multiple outlets under varied flow conditions. The experimental results revealed that the shear flow mode significantly enhances mixing uniformity and droplet generation efficiency compared to continuous flow operations, attributed to intensified interfacial interactions within contraction–expansion serpentine channels. By modulating hydrodynamic parameters such as aqueous- and oil-phase flow rates, this system achieved tunable gradient slopes and droplet sizes, underscoring the intrinsic relationship between flow dynamics and gradient formation. The proposed device eliminates reliance on complex channel networks, offering a compact and scalable platform for parallelized gradient generation. This work provides a robust framework for optimizing microfluidic-based concentration gradient systems, with broad implications for high-throughput screening, combinatorial chemistry, and precision biomolecular assays.
研究领域:
药物筛选
·
化学合成
·
生物分子研究
✓ 已验证
产品关联
DOI
高影响因子
Nano Select
·
2020
·Vol. 2
·期 2
·338-345
·
IF 0
Dege Li,Bingfang Huang,Yi Cao,Molong Han,Xinlei Wu,Qiang Sun,Chi Ma,Lilong Zhao,Peng Liu,Chao Zheng,Hang Dong,Xiaolong Wang,Yonghong Liu,Yanzhen Zhang
The precise and effective generation and manipulation of micron-sized droplets is crucial for chemical and biological research and applications. Normally, droplets generation and manipulation are achieved by two separate devices/systems with their respective operation strategies. Pipette, inkjet nozzle, and microfluidic channels equipped with programed syringes are commonly used for droplets generation whereas the subsequent manipulation is normally achieved by leveraging of forces originating either from optical, electric, magnetic or acoustic field and the corresponding complicated devices. Here we report a new paradigm that can realize simultaneous droplets generation and manipulation in an immiscible liquid environment using only the confined interface vibration generated by the ordinary inkjet nozzle. Droplets, ranging from femtoliter to picoliter, can be generated and manipulated without interruption since they are actuated by the same nozzle. Our strategy provides a platform for precise generation and manipulating the micro-sized droplets that may be valuable for applications requiring simple setups and seamless connection between droplets generation and droplets manipulation.
研究领域:
生物医学工程
·
微流体技术
·
化学工程
✓ 已验证
DOI
Biosensors-Basel
·
2023
·Vol. 13
·期 9
·888
·
IF 5.4
Gangyin Luo,Ying Zhang,Shun Wang,Xinbei Lv,Tianhang Yang,Jinxian Wang
Uniform and stable droplet generation is critical for accurate and efficient digital nucleic acid analysis (dNAA). In this study, an integrated microfluidic step emulsification device with wide-range droplet generation capability, small device dimensions, convenient fabrication strategy, low contamination and high robustness was developed. A tree-shaped droplet generation nozzle distribution design was proposed to increase the uniformity of droplet generation by equating flow rates, and the flow field in the design was numerically simulated. Theoretical analysis and comparative experiments on droplet size were performed regarding the influences of nozzle dimensions and surface properties. With incubation and hydrophobic reagent treatment, droplets as small as 73.1 μm were generated with multiplex nozzles of 18 μm (h) × 80 μm (w). The droplets were then collected into a standard PCR tube and an on-chip monolayer droplet collection chamber, without manual transfer and sample contamination. The oil-to-sample volume ratio in the PCR tube was recorded during collection. In the end, the droplets generated and collected using the microfluidic device proved to be stable and uniform for nucleic acid amplification and detection. This study provides reliable characteristic information for the design and fabrication of a micro-droplet generation device, and represents a promising approach for the realization of a three-in-one dNAA device under a step emulsification method.Keywords:step emulsification;micro-droplet;integrated microfluidic chip;nucleic acid detection
研究领域:
生物技术
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Science
·
2025
·
IF 14.1
Xin Wang,Xiaolu Cai,Chao Wan,Huijuan Yuan,Shunji Li,Yiwei Zhang,Ran Zhao,Yuxi Qin,Yiwei Li,Bi-Feng Liu,Peng Chen
Tailored droplet generation is crucial for droplet microfluidics that involve samples of varying sizes. However, the absence of precise predictive models forces droplet platforms to rely on empiricism derived from extensive experiments, underscoring the need for comprehensive modeling analysis. To address this, a novel customized assembled centrifugal step emulsifier (CASE) is presented by incorporating a “jigsaw puzzles” design to efficiently acquire large-scale experimental data. Numerical simulations are utilized to analyze fluid configurations during step emulsification, identifying a key connection tube that determines droplet size. By training and verifying with the experimental and simulation datasets, a comprehensive theoretical model is established that allows for the preliminary design of the droplet size and generation frequency with an average error rate of 4.8%, successfully filling a critical gap in existing field. This predictive model empowers the CASE to achieve all-in-one functionality, including droplet pre-design, generation, manipulation, and on-site detection. As a proof of concept, multiscale sample analysis ranging from nanoscale nucleic acids to microscale bacteria and 3D cell spheroids is realized in the CASE. In summary, this platform offers valuable guidance for customized droplet generation by centrifugal step emulsifiers and promotes the adoption of droplet microfluidics in biochemical assays.
研究领域:
生物工程
·
化学工程
·
微流体技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LANGMUIR
·
2021
·
IF 3.882
Dege Li,Yi Cao,Bingfang Huang,Molong Han,Xinlei Wu,Qiang Sun,Chao Zheng,Lilong Zhao,Chi Ma,Hui Jin,Xiaolong Wang,Yonghong Liu,Yanzhen Zhang
The precise and effective generation of micron-sized droplets is one of the most common and important issues for droplet-based microfluidics. Active droplet generation makes use of additional energy input in promoting interfacial instabilities for droplet generation. Here, we report a new technique for the active generation of femtoliter droplets in microfluidic systems using confined interfacial vibration (CIV). The CIV is formed at the orifice of a traditional inkjet nozzle first by pushing the liquid out and then pulling it back. Droplets are pinched off during the withdrawal process, and this is different from the current active droplet generation techniques, which only monodirectionally push the liquid out. Droplets with radius ranging from ca. 1 to 28 μm can be actively generated by CIV at an orifice with radius 30 μm, distinguishing from conventional active generation techniques in which the droplets are always comparable or slightly bigger than the orifice. Experimental results showed that the droplet volume can be customized by controlling the intensity of the CIV. The inherent digital nature of the inkjet technique enables easy and precise regulating of the droplet volume, making it seamlessly compatible with the digital microfluidic systems.
研究领域:
生物工程
·
化学工程
·
物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LAB ON A CHIP
·
2018
·Vol. 18
·期 18
·2806-2815
·
IF 5.995
Liping Mei,Mingliang Jin,Shuting Xie,Zhibin Yan,Xin Wang,Guofu Zhou,Albert van den Berg,Lingling Shui
We report an easily-established capillary-based open microfluidic device (COMD) as a simple and robust method for size on-demand generation of monodisperse droplets of various fluidic materials with controllable volume. A device is set up in which a capillary is positioned with its tip close to a flat surface with a precise gap distance in a container. The continuous phase remains static in the container, and the dispersed phase is pumped through the capillary and forms droplets at the exit of the gap. Monodisperse droplets, bubbles and microcapsules of various fluids with diameters of 10–300 μm (picoliter to nanoliter) and generation frequency of 1–1000 Hz are obtained by controlling the gap distance in the range of 5–500 μm. The droplet formation is caused by capillarity-induced narrowing of the dispersed phase at the capillary exit, with droplet size being determined by the gap volume and fluid flow. We find that, at low flow rate, using the same COMD, the generated droplet size is constant, being determined by the gap size; however, at higher flow rate, droplet size increases with the flow rate. Droplet types can be managed by fluids and surface modification of the capillary and bottom surfaces. High throughput droplet generation is achieved by in-parallel integration of multiple capillaries in one device. Such a COMD is simple and easy-to-build without complex microfabrication requirements; however, it is highly robust, flexible and easy-to-operate for size on-demand droplet generation. It offers an opportunity for common laboratories to perform droplet-based assays, and has high potential for high throughput industrial emulsification applications as well.
研究领域:
生物工程
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LAB ON A CHIP
·
2016
·Vol. 16
·期 24
·4718-4724
·
IF 5.586
Tianbao Li,Lei Zhao,Wenming Liu,Juan Xu,Jinyi Wang
A novel, facile, and flexible approach for the easy assembly of microfluidic droplet devices using commercially available components is presented. Three different types of devices have been designed and tested, and the experimental results indicated that the devices offer a promising platform for the controllable generation of highly monodisperse droplets with sizes in the micrometer to millimeter diameter ranges. The advantages of the devices include their low cost, portability, reusability, high accuracy, and reliability. Most importantly, the simple and reversible combination of the different components allows the flexible design of versatile devices for fabricating multiple droplets with diverse structures. Therefore, the devices constitute a powerful microplatform that can be used for scientific and industrial applications.
研究领域:
生物工程
·
化学工程
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
FUEL
·
2020
·
IF 5.578
Yong Zhang,Hongzheng Zhu,Jinbo Zhu,Qinghui Shi,Jianqiang Yin,Dongyang Xu,Alejandro Lόpez Valdivieso
Understanding the generation behavior of kerosene droplets is an important precursor for predicting the kerosene-mineral adsorption. Using a high-speed motion acquisition system, we investigated the thermodynamic and kinetic characteristics of kerosene droplet with different size capillaries. As the capillary inner diameter increased, the formation time of the kerosene droplet become longer, and the width/height value decreased. The width/height value of the kerosene column roughly increased as the capillary inner diameter decreased due to the variation in the buoyancy, gravity and surface tension. The kinetic energy per unit superficial area (E k /S) of the kerosene droplet firstly decreased sharply as the capillary inner diameter increased and then remained almost constant. The energy barrier on the kaolinite, quartz, montmorillonite and coal surfaces was found easy to be overcome by E k /S independently of capillary inner diameter, and the energy barrier on the mica surface could be overcome if the capillary inner diameter was smaller than 0.50 mm. A predictive model of the formation condition of deuterogenic kerosene droplet was established, and the critical capillary inner diameter for forming a deuterogenic kerosene droplet was predicted to be approximately 0.29 mm. This aspect of kerosene droplet characteristics has not been well represented in the earlier literature. The results can provide valuable insight into the development of technology for surfactant adsorption and mineral flotation.
研究领域:
化学工程
·
表面科学
✓ 已验证
DOI
高影响因子
LANGMUIR
·
2018
·
IF 3.789
Youchuang Chao,Sze Yi Mak,Qingming Ma,Jing Wu,Zijing Ding,Lei Xu,Ho Cheung Shum
The interfacial phenomena at liquid–liquid interfaces remain the subject of constant fascination in science and technology. Here, we show that fingers forming at the interface of nonequilibrium all-aqueous systems can spontaneously break into an array of droplets. The dynamic formation of droplets at the water–water (w/w) interface is observed when a less dense aqueous phase, for instance, the dextran solution, is placed on a denser aqueous phase, the polyethylene glycol solution, in a vertical Hele-Shaw cell. Because of the gradual diffusion of water from the upper phase into the lower phase, a dense layer appears at the nonequilibrium w/w interface. As a result, a periodic array of fingers emerge and sink. Remarkably, these fingers break up and an array of droplets are emitted from the interface. We characterize the wavelength of fingering by measuring the average distance between the dominant fingers. By varying the initial concentrations of the two nonequilibrium aqueous phases, we identify experimentally a phase diagram with a wide parameter space in which finger breaking occurs. Finally, plenty of droplets, spontaneously formed when one phase is continuously deposited onto another aqueous phase, further confirm the robustness of our experimental results. Our work suggests a simple yet efficient approach with a potential upscalability to generate all-aqueous droplets.
研究领域:
物理学
·
材料科学
·
流体力学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
AICHE JOURNAL
·
2021
·Vol. 68
·期 1
·e17395
·
IF 3.993
Xiyang Liu,Ziwei Liu,Shaokun Jiang,Chunying Zhu,Youguang Ma,Taotao Fu
In this paper, the formation mechanism of droplets of shear-thinning non-Newtonian fluids in a step-emulsification microdevice is studied experimentally, by using aqueous solutions of sodium carboxymethyl cellulose (CMC) as the dispersed phase and cyclohexane as the continuous phase. According to the evolution of the front-end length of the dispersed thread over time, the droplet generation process is divided into three stages: the two-dimensional expansion stage, the three-dimensional rapid expansion stage, and the necking stage. The influence of the dispersed phase flow rate Q d and CMC concentration c on droplet formation is described. The results show that the addition of CMC in the aqueous solution increases the viscosity of the dispersed phase and slows down the evolution of the dispersed phase, thereby resulting in the increase of the droplet size. Finally, a droplet volume prediction model considering non-Newtonian characteristics is proposed, and the formation of satellite droplets is analyzed.
研究领域:
流体力学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
AIP Advances
·
2019
·Vol. 9
·期 10
·
IF 1.579
Zhu Xiurui,Su Shisheng,Liu Baoxia,Zhu Lingxiang,Yang Wenjun,Gao Na,Jing Gaoshan,Guo Yong
Droplet microfluidics is becoming an enabling technology for synthesizing microscale particles and an effective real-time method is essential to monitor the variations in a dynamic droplet generation process. Here, a novel real-time cosine similarity algorithm (RT-CSA) method was developed to investigate the droplet generation process by measuring the droplet generation frequency continuously. The RT-CSA method uses a first-in-first-out (FIFO) similarity vector buffer to store calculated cosine similarities, so that these cosine similarities are reused to update the calculation results once a new frame is captured and stored. For the first time, the RT-CSA method achieved real-time monitoring of dynamic droplet generation processes by updating calculation results over 2,000 times per second, and two pre-microgel droplet generation processes with or without artificial disturbances were monitored closely and continuously. With the RT-CSA method, the disturbances in dynamic droplet generation processes were precisely determined, and following changes were monitored and recorded in real time. This highly effective RT-CSA method could be a powerful tool for further promoting research of droplet microfluidics.
研究领域:
生物工程
·
微流体技术
·
算法开发
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）