Ultrasound reforms droplets
(2024) In Lab on a Chip 24(19). p.4649-4658- Abstract
Size-controlled monodisperse droplets are indispensable in food, cosmetics, and healthcare industries. Although emulsion formation from bulk phases is well-explored, a robust in situ method to continuously reform existing emulsions is unavailable. Remarkably, we introduce a continuous flow acousto-microfluidics technique which enables simultaneous trapping-coalescence-splitting of droplets to reform an existing polydisperse emulsion into size-controlled droplets with improved monodispersity. In contrast to conventional approaches, our platform enables controlling droplet characteristics in situ by regulating acoustic power without altering hydrodynamical parameters thereby improving response time and facilitates continuous nozzle-less... (More)
Size-controlled monodisperse droplets are indispensable in food, cosmetics, and healthcare industries. Although emulsion formation from bulk phases is well-explored, a robust in situ method to continuously reform existing emulsions is unavailable. Remarkably, we introduce a continuous flow acousto-microfluidics technique which enables simultaneous trapping-coalescence-splitting of droplets to reform an existing polydisperse emulsion into size-controlled droplets with improved monodispersity. In contrast to conventional approaches, our platform enables controlling droplet characteristics in situ by regulating acoustic power without altering hydrodynamical parameters thereby improving response time and facilitates continuous nozzle-less clogging-free droplet generation from a liquid plug in a chamber instead of from a liquid stream at a narrow junction. The technique can process polydisperse droplets produced not only due to fluid-source fluctuations or unstable jetting regime but also externally by non-microfluidic or inexpensive setups. Our theoretical scaling suggests that the sum of capillary (Ca) and acousto-capillary (Caa) numbers ∼ 00010110 00111011 01010001 10000001 10000001 10000010 10000010 11000100 01111000 (1), and predicts the generated droplet size, both agreeing well with the experimental findings. We identify acousto-visco-capillary number, Caav = (Ca Caa)1/2, which governs the generated droplet size. We also explore and characterize acoustic streaming- and coalescence-based mixing of samples inside the trapped plug. Distinctively, our platform is amenable to continuous mixing of inhomogeneous droplets, offering monodisperse mixed-sample droplets, and holds the potential to match current throughput standards through suitable design modifications.
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- author
- Malik, Lokesh ; Nandy, Subhas ; Satpathi, Niladri Sekhar ; Ghosh, Debasish ; Laurell, Thomas LU and Sen, Ashis Kumar
- organization
-
- Division for Biomedical Engineering
- NanoLund: Centre for Nanoscience
- MultiPark: Multidisciplinary research focused on Parkinson's disease
- LTH Profile Area: Engineering Health
- LTH Profile Area: Nanoscience and Semiconductor Technology
- LU Profile Area: Light and Materials
- LUCC: Lund University Cancer Centre
- publishing date
- 2024
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Lab on a Chip
- volume
- 24
- issue
- 19
- pages
- 10 pages
- publisher
- Royal Society of Chemistry
- external identifiers
-
- scopus:85202958536
- pmid:39225030
- ISSN
- 1473-0197
- DOI
- 10.1039/d4lc00507d
- language
- English
- LU publication?
- yes
- id
- 2114fc50-90c6-4d3c-9868-986f24d427ce
- date added to LUP
- 2024-12-13 14:11:16
- date last changed
- 2025-07-12 20:22:36
@article{2114fc50-90c6-4d3c-9868-986f24d427ce,
abstract = {{<p>Size-controlled monodisperse droplets are indispensable in food, cosmetics, and healthcare industries. Although emulsion formation from bulk phases is well-explored, a robust in situ method to continuously reform existing emulsions is unavailable. Remarkably, we introduce a continuous flow acousto-microfluidics technique which enables simultaneous trapping-coalescence-splitting of droplets to reform an existing polydisperse emulsion into size-controlled droplets with improved monodispersity. In contrast to conventional approaches, our platform enables controlling droplet characteristics in situ by regulating acoustic power without altering hydrodynamical parameters thereby improving response time and facilitates continuous nozzle-less clogging-free droplet generation from a liquid plug in a chamber instead of from a liquid stream at a narrow junction. The technique can process polydisperse droplets produced not only due to fluid-source fluctuations or unstable jetting regime but also externally by non-microfluidic or inexpensive setups. Our theoretical scaling suggests that the sum of capillary (Ca) and acousto-capillary (Ca<sub>a</sub>) numbers ∼ 00010110 00111011 01010001 10000001 10000001 10000010 10000010 11000100 01111000 (1), and predicts the generated droplet size, both agreeing well with the experimental findings. We identify acousto-visco-capillary number, Ca<sub>av</sub> = (Ca Ca<sub>a</sub>)<sup>1/2</sup>, which governs the generated droplet size. We also explore and characterize acoustic streaming- and coalescence-based mixing of samples inside the trapped plug. Distinctively, our platform is amenable to continuous mixing of inhomogeneous droplets, offering monodisperse mixed-sample droplets, and holds the potential to match current throughput standards through suitable design modifications.</p>}},
author = {{Malik, Lokesh and Nandy, Subhas and Satpathi, Niladri Sekhar and Ghosh, Debasish and Laurell, Thomas and Sen, Ashis Kumar}},
issn = {{1473-0197}},
language = {{eng}},
number = {{19}},
pages = {{4649--4658}},
publisher = {{Royal Society of Chemistry}},
series = {{Lab on a Chip}},
title = {{Ultrasound reforms droplets}},
url = {{http://dx.doi.org/10.1039/d4lc00507d}},
doi = {{10.1039/d4lc00507d}},
volume = {{24}},
year = {{2024}},
}