Monodisperse Micro-Droplet Generation in Microfluidic Channel with Asymmetric Cross-Sectional Shape
Micro-droplets are widely used in the fields of chemical and biological research, such as drug delivery, material synthesis, point-of-care diagnostics, and digital PCR. Droplet-based microfluidics has many advantages, such as small reagent consumption, fast reaction time, and independent control of...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-01-01
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| Series: | Micromachines |
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| Online Access: | https://www.mdpi.com/2072-666X/14/1/223 |
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| author | Youngseo Cho Jungwoo Kim Jaewon Park Hyun Soo Kim Younghak Cho |
| author_facet | Youngseo Cho Jungwoo Kim Jaewon Park Hyun Soo Kim Younghak Cho |
| author_sort | Youngseo Cho |
| collection | DOAJ |
| description | Micro-droplets are widely used in the fields of chemical and biological research, such as drug delivery, material synthesis, point-of-care diagnostics, and digital PCR. Droplet-based microfluidics has many advantages, such as small reagent consumption, fast reaction time, and independent control of each droplet. Therefore, various micro-droplet generation methods have been proposed, including T-junction breakup, capillary flow-focusing, planar flow-focusing, step emulsification, and high aspect (height-to-width) ratio confinement. In this study, we propose a microfluidic device for generating monodisperse micro-droplets, the microfluidic channel of which has an asymmetric cross-sectional shape and high hypotenuse-to-width ratio (HTWR). It was fabricated using basic MEMS processes, such as photolithography, anisotropic wet etching of Si, and polydimethylsiloxane (PDMS) molding. Due to the geometric similarity of a Si channel and a PDMS mold, both of which were created through the anisotropic etching process of a single crystal Si, the microfluidic channel with the asymmetric cross-sectional shape and high HTWR was easily realized. The effects of HTWR of channels on the size and uniformity of generated micro-droplets were investigated. The monodisperse micro-droplets were generated as the HTWR of the asymmetric channel was over 3.5. In addition, it was found that the flow direction of the oil solution (continuous phase) affected the size of micro-droplets due to the asymmetric channel structures. Two kinds of monodisperse droplets with different sizes were successfully generated for a wider range of flow rates using the asymmetric channel structure in the developed microfluidic device. |
| first_indexed | 2024-03-09T11:40:41Z |
| format | Article |
| id | doaj.art-dbb29ef1f4b3403cafba30018fa81f58 |
| institution | Directory Open Access Journal |
| issn | 2072-666X |
| language | English |
| last_indexed | 2024-03-09T11:40:41Z |
| publishDate | 2023-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Micromachines |
| spelling | doaj.art-dbb29ef1f4b3403cafba30018fa81f582023-11-30T23:34:54ZengMDPI AGMicromachines2072-666X2023-01-0114122310.3390/mi14010223Monodisperse Micro-Droplet Generation in Microfluidic Channel with Asymmetric Cross-Sectional ShapeYoungseo Cho0Jungwoo Kim1Jaewon Park2Hyun Soo Kim3Younghak Cho4Department of Mechanical System Design Engineering, Seoul National University of Science & Technology, 232 Gongneung-ro, Nowon-gu, Seoul 01811, Republic of KoreaDepartment of Mechanical System Design Engineering, Seoul National University of Science & Technology, 232 Gongneung-ro, Nowon-gu, Seoul 01811, Republic of KoreaOJEong Resilience Institute (OJERI), Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of KoreaDepartment of Electronic Engineering, Kwangwoon University, 20 Kwangwoon-ro, Nowon-gu, Seoul 01897, Republic of KoreaDepartment of Mechanical System Design Engineering, Seoul National University of Science & Technology, 232 Gongneung-ro, Nowon-gu, Seoul 01811, Republic of KoreaMicro-droplets are widely used in the fields of chemical and biological research, such as drug delivery, material synthesis, point-of-care diagnostics, and digital PCR. Droplet-based microfluidics has many advantages, such as small reagent consumption, fast reaction time, and independent control of each droplet. Therefore, various micro-droplet generation methods have been proposed, including T-junction breakup, capillary flow-focusing, planar flow-focusing, step emulsification, and high aspect (height-to-width) ratio confinement. In this study, we propose a microfluidic device for generating monodisperse micro-droplets, the microfluidic channel of which has an asymmetric cross-sectional shape and high hypotenuse-to-width ratio (HTWR). It was fabricated using basic MEMS processes, such as photolithography, anisotropic wet etching of Si, and polydimethylsiloxane (PDMS) molding. Due to the geometric similarity of a Si channel and a PDMS mold, both of which were created through the anisotropic etching process of a single crystal Si, the microfluidic channel with the asymmetric cross-sectional shape and high HTWR was easily realized. The effects of HTWR of channels on the size and uniformity of generated micro-droplets were investigated. The monodisperse micro-droplets were generated as the HTWR of the asymmetric channel was over 3.5. In addition, it was found that the flow direction of the oil solution (continuous phase) affected the size of micro-droplets due to the asymmetric channel structures. Two kinds of monodisperse droplets with different sizes were successfully generated for a wider range of flow rates using the asymmetric channel structure in the developed microfluidic device.https://www.mdpi.com/2072-666X/14/1/223monodisperse micro-dropletasymmetric cross-sectionmicro-droplet generationhypotenuse-to-width ratio (HTWR) |
| spellingShingle | Youngseo Cho Jungwoo Kim Jaewon Park Hyun Soo Kim Younghak Cho Monodisperse Micro-Droplet Generation in Microfluidic Channel with Asymmetric Cross-Sectional Shape Micromachines monodisperse micro-droplet asymmetric cross-section micro-droplet generation hypotenuse-to-width ratio (HTWR) |
| title | Monodisperse Micro-Droplet Generation in Microfluidic Channel with Asymmetric Cross-Sectional Shape |
| title_full | Monodisperse Micro-Droplet Generation in Microfluidic Channel with Asymmetric Cross-Sectional Shape |
| title_fullStr | Monodisperse Micro-Droplet Generation in Microfluidic Channel with Asymmetric Cross-Sectional Shape |
| title_full_unstemmed | Monodisperse Micro-Droplet Generation in Microfluidic Channel with Asymmetric Cross-Sectional Shape |
| title_short | Monodisperse Micro-Droplet Generation in Microfluidic Channel with Asymmetric Cross-Sectional Shape |
| title_sort | monodisperse micro droplet generation in microfluidic channel with asymmetric cross sectional shape |
| topic | monodisperse micro-droplet asymmetric cross-section micro-droplet generation hypotenuse-to-width ratio (HTWR) |
| url | https://www.mdpi.com/2072-666X/14/1/223 |
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