Ferrofluid droplet generation on a zero-thickness nozzle by a magnetic field using a wedge-shaped functional surface.
Digital microfluidics for ferrofluids enables the manipulation of discrete droplets on open surfaces and has garnered significant interest as an alternative to traditional continuous-flow microfluidic systems. However, droplet generation within digital microfluidics remain underdeveloped. This study...
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2025-01-01
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| Series: | PLoS ONE |
| Online Access: | https://doi.org/10.1371/journal.pone.0321099 |
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| author | Amirhossein Favakeh Mohamad Ali Bijarchi Mahbod Mohammadrashidi Mohammad Yaghoobi Mohammad Behshad Shafii |
| author_facet | Amirhossein Favakeh Mohamad Ali Bijarchi Mahbod Mohammadrashidi Mohammad Yaghoobi Mohammad Behshad Shafii |
| author_sort | Amirhossein Favakeh |
| collection | DOAJ |
| description | Digital microfluidics for ferrofluids enables the manipulation of discrete droplets on open surfaces and has garnered significant interest as an alternative to traditional continuous-flow microfluidic systems. However, droplet generation within digital microfluidics remain underdeveloped. This study introduces a novel method for droplet generation using a wedge-shaped surface with hydrophilic-hydrophobic patterning, which functions as a two-dimensional flat nozzle. We first demonstrated the concept by investigating gravity-driven water droplet generation on a sloping surface, revealing that smaller droplets form at higher tilting angles, while droplet size remains constant with increasing flow rate. Frequency of droplet formation decreases by 60% with decreasing the tilting angle from 90° to 30°. The proposed method results in significant improvement in frequency (10 Hz) compared to nozzle-based droplet generation (1-5 Hz). We then extend this approach to ferrofluid droplets under an external magnetic field, observing five distinct steps in the formation process. Additionally, a scale analysis of both water and ferrofluid droplet generation provides a deeper theoretical understanding of the governing forces, showing a strong correlation between non-dimensional droplet diameter and the Bond number, following a -1/3 power law (R2 > 0.95). The derived empirical factor offers precise droplet diameter predictions, with an average error of 3.9%. Finally, inspired by cactus structures, we demonstrate parallelization of the flat nozzles, highlighting the potential for high-throughput droplet generation in digital microfluidic applications. |
| format | Article |
| id | doaj-art-d777922cb14f4c37a8a010c2f13d3c7d |
| institution | OA Journals |
| issn | 1932-6203 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj-art-d777922cb14f4c37a8a010c2f13d3c7d2025-08-20T02:34:10ZengPublic Library of Science (PLoS)PLoS ONE1932-62032025-01-01205e032109910.1371/journal.pone.0321099Ferrofluid droplet generation on a zero-thickness nozzle by a magnetic field using a wedge-shaped functional surface.Amirhossein FavakehMohamad Ali BijarchiMahbod MohammadrashidiMohammad YaghoobiMohammad Behshad ShafiiDigital microfluidics for ferrofluids enables the manipulation of discrete droplets on open surfaces and has garnered significant interest as an alternative to traditional continuous-flow microfluidic systems. However, droplet generation within digital microfluidics remain underdeveloped. This study introduces a novel method for droplet generation using a wedge-shaped surface with hydrophilic-hydrophobic patterning, which functions as a two-dimensional flat nozzle. We first demonstrated the concept by investigating gravity-driven water droplet generation on a sloping surface, revealing that smaller droplets form at higher tilting angles, while droplet size remains constant with increasing flow rate. Frequency of droplet formation decreases by 60% with decreasing the tilting angle from 90° to 30°. The proposed method results in significant improvement in frequency (10 Hz) compared to nozzle-based droplet generation (1-5 Hz). We then extend this approach to ferrofluid droplets under an external magnetic field, observing five distinct steps in the formation process. Additionally, a scale analysis of both water and ferrofluid droplet generation provides a deeper theoretical understanding of the governing forces, showing a strong correlation between non-dimensional droplet diameter and the Bond number, following a -1/3 power law (R2 > 0.95). The derived empirical factor offers precise droplet diameter predictions, with an average error of 3.9%. Finally, inspired by cactus structures, we demonstrate parallelization of the flat nozzles, highlighting the potential for high-throughput droplet generation in digital microfluidic applications.https://doi.org/10.1371/journal.pone.0321099 |
| spellingShingle | Amirhossein Favakeh Mohamad Ali Bijarchi Mahbod Mohammadrashidi Mohammad Yaghoobi Mohammad Behshad Shafii Ferrofluid droplet generation on a zero-thickness nozzle by a magnetic field using a wedge-shaped functional surface. PLoS ONE |
| title | Ferrofluid droplet generation on a zero-thickness nozzle by a magnetic field using a wedge-shaped functional surface. |
| title_full | Ferrofluid droplet generation on a zero-thickness nozzle by a magnetic field using a wedge-shaped functional surface. |
| title_fullStr | Ferrofluid droplet generation on a zero-thickness nozzle by a magnetic field using a wedge-shaped functional surface. |
| title_full_unstemmed | Ferrofluid droplet generation on a zero-thickness nozzle by a magnetic field using a wedge-shaped functional surface. |
| title_short | Ferrofluid droplet generation on a zero-thickness nozzle by a magnetic field using a wedge-shaped functional surface. |
| title_sort | ferrofluid droplet generation on a zero thickness nozzle by a magnetic field using a wedge shaped functional surface |
| url | https://doi.org/10.1371/journal.pone.0321099 |
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