1
|
Huang B, Xie H, Li Z. Microfluidic Methods for Generation of Submicron Droplets: A Review. MICROMACHINES 2023; 14:638. [PMID: 36985045 PMCID: PMC10056697 DOI: 10.3390/mi14030638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 03/07/2023] [Accepted: 03/08/2023] [Indexed: 06/18/2023]
Abstract
Submicron droplets are ubiquitous in nature and widely applied in fields such as biomedical diagnosis and therapy, oil recovery and energy conversion, among others. The submicron droplets are kinetically stable, their submicron size endows them with good mobility in highly constricted pathways, and the high surface-to-volume ratio allows effective loading of chemical components at the interface and good heat transfer performance. Conventional generation technology of submicron droplets in bulk involves high energy input, or relies on chemical energy released from the system. Microfluidic methods are widely used to generate highly monodispersed micron-sized or bigger droplets, while downsizing to the order of 100 nm was thought to be challenging because of sophisticated nanofabrication. In this review, we summarize the microfluidic methods that are promising for the generation of submicron droplets, with an emphasize on the device fabrication, operational condition, and resultant droplet size. Microfluidics offer a relatively energy-efficient and versatile tool for the generation of highly monodisperse submicron droplets.
Collapse
|
2
|
Nordin AN, Abd Manaf A. Design and fabrication technologies for microfluidic sensors. MICROFLUIDIC BIOSENSORS 2023:41-85. [DOI: 10.1016/b978-0-12-823846-2.00004-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
|
3
|
Zeng W, Yang S, Liu Y, Yang T, Tong Z, Shan X, Fu H. Precise monodisperse droplet generation by pressure-driven microfluidic flows. Chem Eng Sci 2022. [DOI: 10.1016/j.ces.2021.117206] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
4
|
Monodisperse droplet formation for both low and high capillary numbers in a T-junction microdroplet generator. Chem Eng Sci 2021. [DOI: 10.1016/j.ces.2021.116799] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
5
|
Tanaka D, Kajiya S, Shijo S, Yoon DH, Furuya M, Nozaki Y, Fujita H, Sekiguchi T, Shoji S. Efficient Generation of Microdroplets Using Tail Breakup Induced with Multi-Branch Channels. Molecules 2021; 26:3707. [PMID: 34204558 PMCID: PMC8235478 DOI: 10.3390/molecules26123707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 06/10/2021] [Accepted: 06/14/2021] [Indexed: 11/16/2022] Open
Abstract
In recent years, research on the application of microdroplets in the fields of biotechnology and chemistry has made remarkable progress, but the technology for the stable generation of single-micrometer-scale microdroplets has not yet been established. In this paper, we developed an efficient and stable single-micrometer-scale droplet generation device based on the fragmentation of droplet tails, called "tail thread mode", that appears under moderate flow conditions. This method can efficiently encapsulate microbeads that mimic cells and chemical products in passively generated single-micrometer-scale microdroplets. The device has a simple 2D structure; a T-junction is used for droplet generation; and in the downstream, multi-branch channels are designed for droplet deformation into the tail. Several 1-2 µm droplets were successfully produced by the tail's fragmentation; this continuous splitting was induced by the branch channels. We examined a wide range of experimental conditions and found the optimal flow rate condition can be reduced to one-tenth compared to the conventional tip-streaming method. A mold was fabricated by simple soft lithography, and a polydimethylsiloxane (PDMS) device was fabricated using the mold. Based on the 15 patterns of experimental conditions and the results, the key factors for the generation of microdroplets in this device were examined. In the most efficient condition, 61.1% of the total droplets generated were smaller than 2 μm.
Collapse
Affiliation(s)
- Daiki Tanaka
- Research Organization for Nano & Life Innovation, Waseda University, 513 Wasedatsurumakicho, Shinjuku-ku, Tokyo 162-0041, Japan; (D.H.Y.); (Y.N.); (T.S.)
| | - Satsuki Kajiya
- Department of Electronic and Physical Systems, School of Fundamental Science and Engineering, Waseda University, 3-4-1 Okubo, Shin-juku-ku, Tokyo 145-0065, Japan; (S.K.); (S.S.); (M.F.); (S.S.)
| | - Seito Shijo
- Department of Electronic and Physical Systems, School of Fundamental Science and Engineering, Waseda University, 3-4-1 Okubo, Shin-juku-ku, Tokyo 145-0065, Japan; (S.K.); (S.S.); (M.F.); (S.S.)
| | - Dong Hyun Yoon
- Research Organization for Nano & Life Innovation, Waseda University, 513 Wasedatsurumakicho, Shinjuku-ku, Tokyo 162-0041, Japan; (D.H.Y.); (Y.N.); (T.S.)
| | - Masahiro Furuya
- Department of Electronic and Physical Systems, School of Fundamental Science and Engineering, Waseda University, 3-4-1 Okubo, Shin-juku-ku, Tokyo 145-0065, Japan; (S.K.); (S.S.); (M.F.); (S.S.)
| | - Yoshito Nozaki
- Research Organization for Nano & Life Innovation, Waseda University, 513 Wasedatsurumakicho, Shinjuku-ku, Tokyo 162-0041, Japan; (D.H.Y.); (Y.N.); (T.S.)
| | - Hiroyuki Fujita
- Canon Medical Systems Corporation, 1385 Shimoishigami, Otawara-shi, Tochigi 324-8550, Japan;
| | - Tetsushi Sekiguchi
- Research Organization for Nano & Life Innovation, Waseda University, 513 Wasedatsurumakicho, Shinjuku-ku, Tokyo 162-0041, Japan; (D.H.Y.); (Y.N.); (T.S.)
| | - Shuichi Shoji
- Department of Electronic and Physical Systems, School of Fundamental Science and Engineering, Waseda University, 3-4-1 Okubo, Shin-juku-ku, Tokyo 145-0065, Japan; (S.K.); (S.S.); (M.F.); (S.S.)
| |
Collapse
|
6
|
|
7
|
Concepts for efficient preparation of particulate polymer carrier systems by droplet-based microfluidics. Int J Pharm 2020; 584:119401. [DOI: 10.1016/j.ijpharm.2020.119401] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 04/30/2020] [Accepted: 05/02/2020] [Indexed: 02/07/2023]
|
8
|
Prediction of Droplet Production Speed by Measuring the Droplet Spacing Fluctuations in a Flow-Focusing Microdroplet Generator. MICROMACHINES 2019; 10:mi10120812. [PMID: 31775320 PMCID: PMC6952780 DOI: 10.3390/mi10120812] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 11/18/2019] [Accepted: 11/20/2019] [Indexed: 01/09/2023]
Abstract
In a flow-focusing microdroplet generator, by changing the flow rates of the two immiscible fluids, production speed can be increased from tens to thousands of droplets per second. However, because of the nonlinearity of the flow-focusing microdroplet generator, the production speed of droplets is difficult to quantitatively study for the typical flow-focusing geometry. In this paper, we demonstrate an efficient method that can precisely predict the droplet production speed for a wide range of fluid flow rates. While monodisperse droplets are formed in the flow-focusing microchannel, droplet spacing as a function of time was measured experimentally. We discovered that droplet spacing changes periodically with time during each process of droplet generation. By comparing the frequency of droplet spacing fluctuations with the droplet production speed, precise predictions of droplet production speed can be obtained for different flow conditions in the flow-focusing microdroplet generator.
Collapse
|
9
|
Wu Y, Qian X, Mi S, Zhang M, Sun S, Wang X. Generation of Size-controlled Poly (ethylene Glycol) Diacrylate Droplets via Semi-3-Dimensional Flow Focusing Microfluidic Devices. J Vis Exp 2018:57198. [PMID: 30035768 PMCID: PMC6102036 DOI: 10.3791/57198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Uniform and size-controllable poly (ethylene glycol) diacrylate (PEGDA) droplets could be produced via the flow focusing process in a microfluidic device. This paper proposes a semi-three-dimensional (semi-3D) flow-focusing microfluidic chip for droplet formation. The polydimethylsiloxane (PDMS) chip was fabricated using the multi-layer soft lithography method. Hexadecane containing surfactant was used as the continuous phase, and PEGDA with the ultraviolet (UV) photo-initiator was the dispersed phase. Surfactants allowed the local surface tension to drop and formed a more cusped tip which promoted breaking into tiny micro-droplets. As the pressure of dispersed phase was constant, the size of droplets became smaller with increasing continuous phase pressure before dispersed phase flow was broken off. As a result, droplets with size variation from 1 µm to 80 µm in diameter could be selectively achieved by changing the pressure ratio in two inlet channels, and the average coefficient of variation was estimated to be below 7%. Furthermore, droplets could turn into micro-beads by UV exposure for photo-polymerization. Conjugating biomolecules on such micro-beads surface have many potential applications in the fields of biology and chemistry.
Collapse
Affiliation(s)
- Yan Wu
- Graduate School at Shenzhen, Tsinghua University
| | - Xiang Qian
- Graduate School at Shenzhen, Tsinghua University;
| | - Shengli Mi
- Graduate School at Shenzhen, Tsinghua University
| | - Min Zhang
- Graduate School at Shenzhen, Tsinghua University
| | - Shuqing Sun
- Graduate School at Shenzhen, Tsinghua University
| | - Xiaohao Wang
- Graduate School at Shenzhen, Tsinghua University; The State Key Laboratory of Precision Measurement Technology and Instruments, Tsinghua University
| |
Collapse
|
10
|
Wu Y, Qian X, Zhang M, Dong Y, Sun S, Wang X. Mode Transition of Droplet Formation in a Semi-3D Flow-Focusing Microfluidic Droplet System. MICROMACHINES 2018; 9:mi9040139. [PMID: 30424073 PMCID: PMC6187513 DOI: 10.3390/mi9040139] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 03/07/2018] [Accepted: 03/19/2018] [Indexed: 11/18/2022]
Abstract
Uniform droplets have significant potential in many biological applications due to their higher surface area to volume ratio. This paper proposed a semi-three-dimensional (sime-3D) flow-focusing microfluidic system, which was fabricated using the multi-layer soft lithography method. Based on the semi-3D structure, we focus on droplets formation modes and droplet uniformity at different bulk concentration of surfactant. The relationships between droplets uniformity, droplets breakup processes (jetting mode, dripping mode and tip-streaming mode) and surfactant concentration was investigated. It was found that three droplet generation modes occur through adjusting the pressure ratio in two inlet channels and the concentration of surfactant in continuous phase liquid. The jetting mode would transform to the dripping mode or the tip-streaming mode as the pressure ratio in different surfactant concentrations increased. Furthermore, the uniformity of droplets could be improved through the transition of jetting to dripping mode. We assumed that the uniformity declined through the transition of jetting to tip-streaming, and explored the specific transitions from jetting to dripping mode and tip-streaming mode. Dripping mode leads to high droplet uniformity, and generation frequency decreases with increasing pressure ratio. Tip-streaming mode is considered as an extreme state of jetting mode, leading to higher formation frequency and smaller droplet size at low uniformity.
Collapse
Affiliation(s)
- Yan Wu
- Division of Advanced Manufacturing, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.
| | - Xiang Qian
- Division of Advanced Manufacturing, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.
| | - Min Zhang
- Division of Advanced Manufacturing, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.
| | - Ying Dong
- Division of Advanced Manufacturing, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China. ,edu.cn
| | - Shuqing Sun
- Institute of Optical Imaging and Sensing, Shenzhen Key Laboratory for Minimal Invasive Medical Technologies, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.
| | - Xiaohao Wang
- Division of Advanced Manufacturing, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.
- The State Key Laboratory of Precision Measurement Technology and Instruments, Tsinghua University, Beijing 100084, China.
| |
Collapse
|
11
|
Xu X, Song R, He M, Peng C, Yu M, Hou Y, Qiu H, Zou R, Yao S. Microfluidic production of nanoscale perfluorocarbon droplets as liquid contrast agents for ultrasound imaging. LAB ON A CHIP 2017; 17:3504-3513. [PMID: 28933795 DOI: 10.1039/c7lc00056a] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Liquid perfluorocarbon (PFC) nanodroplets may have a better chance to extravasate through inter-endothelial gaps (400-800 nm) into tumor interstitium for extravascular imaging, which holds promise as an innovative strategy for imaging-guided drug delivery, early diagnosis of cancer and minimally invasive treatment of cancer. Currently available emulsion technologies still face challenges in reducing droplet sizes from the microscale to the nanoscale. To control size and ensure monodispersity of PFC nanodroplets, we developed a flame-shaped glass capillary and polydimethylsiloxane (PDMS) hybrid device that creates a concentric flow of the dispersed phase enclosed by the focusing continuous phase at the cross-junction. Through adjustment of the pressure applied, a stable tip-streaming mode can be obtained for PFC nanodroplet generation. Using this device, we synthesized various kinds of PFC nanodroplets as small as 200 nm in diameter with polydispersity index (PDI) <0.04. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) were carried out for the characterization of the PFC nanodroplets. Finally, ultrasound imaging was conducted to demonstrate that the liquid PFC nanodroplets can be used for enhancing the ultrasound contrast upon vaporization.
Collapse
Affiliation(s)
- Xiaonan Xu
- Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Hong Kong, China.
| | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Ballard N, Salsamendi M, Carretero P, Asua JM. An investigation into the nature and potential of in-situ surfactants for low energy miniemulsification. J Colloid Interface Sci 2015. [DOI: 10.1016/j.jcis.2015.07.041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
13
|
|
14
|
Li YK, Liu GT, Xu JH, Wang K, Luo GS. A microdevice for producing monodispersed droplets under a jetting flow. RSC Adv 2015. [DOI: 10.1039/c5ra02397a] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
A new capillary extended step microchannel for generating monodispersed droplets with a much wider narrowing jetting flow regime was specially designed.
Collapse
Affiliation(s)
- Y. K. Li
- The State Key Laboratory of Chemical Engineering
- Department of Chemical Engineering
- Tsinghua University
- Beijing
- China
| | - G. T. Liu
- The State Key Laboratory of Chemical Engineering
- Department of Chemical Engineering
- Tsinghua University
- Beijing
- China
| | - J. H. Xu
- The State Key Laboratory of Chemical Engineering
- Department of Chemical Engineering
- Tsinghua University
- Beijing
- China
| | - K. Wang
- The State Key Laboratory of Chemical Engineering
- Department of Chemical Engineering
- Tsinghua University
- Beijing
- China
| | - G. S. Luo
- The State Key Laboratory of Chemical Engineering
- Department of Chemical Engineering
- Tsinghua University
- Beijing
- China
| |
Collapse
|