High throughput microfluidic nanobubble generation by microporous membrane integration and controlled bubble shrinkage

Ali A Paknahad; Intesar O Zalloum; Raffi Karshafian; Michael C Kolios; Scott S H Tsai

doi:10.1016/j.jcis.2023.09.066

High throughput microfluidic nanobubble generation by microporous membrane integration and controlled bubble shrinkage

J Colloid Interface Sci. 2024 Jan;653(Pt A):277-284. doi: 10.1016/j.jcis.2023.09.066. Epub 2023 Sep 10.

Authors

Ali A Paknahad¹, Intesar O Zalloum², Raffi Karshafian², Michael C Kolios³, Scott S H Tsai⁴

Affiliations

¹ Department of Mechanical and Industrial Engineering, Toronto Metropolitan University, Toronto, Ontario M5B 2K3, Canada; Institute for Biomedical Engineering, Science and Technology (iBEST), A Partnership Between Toronto Metropolitan University and St. Michael's Hospital, Toronto, Ontario M5B 1T8, Canada; Keenan Research Centre for Biomedical Science, Unity Health Toronto, Toronto, Ontario M5B 1W8, Canada.
² Institute for Biomedical Engineering, Science and Technology (iBEST), A Partnership Between Toronto Metropolitan University and St. Michael's Hospital, Toronto, Ontario M5B 1T8, Canada; Keenan Research Centre for Biomedical Science, Unity Health Toronto, Toronto, Ontario M5B 1W8, Canada; Department of Physics, Toronto Metropolitan University, Toronto, Ontario M5B 2K3, Canada.
³ Institute for Biomedical Engineering, Science and Technology (iBEST), A Partnership Between Toronto Metropolitan University and St. Michael's Hospital, Toronto, Ontario M5B 1T8, Canada; Keenan Research Centre for Biomedical Science, Unity Health Toronto, Toronto, Ontario M5B 1W8, Canada; Department of Physics, Toronto Metropolitan University, Toronto, Ontario M5B 2K3, Canada. Electronic address: mkolios@torontomu.ca.
⁴ Department of Mechanical and Industrial Engineering, Toronto Metropolitan University, Toronto, Ontario M5B 2K3, Canada; Institute for Biomedical Engineering, Science and Technology (iBEST), A Partnership Between Toronto Metropolitan University and St. Michael's Hospital, Toronto, Ontario M5B 1T8, Canada; Keenan Research Centre for Biomedical Science, Unity Health Toronto, Toronto, Ontario M5B 1W8, Canada; Graduate Program in Biomedical Engineering, Toronto Metropolitan University, Toronto M5B 2K3, Canada. Electronic address: scott.tsai@torontomu.ca.

PMID: 37716307
DOI: 10.1016/j.jcis.2023.09.066

Abstract

Microfluidics has recently been proposed as a viable method for producing bulk nanobubbles for use in various applications. The portability, compact size, and capacity to precisely control fluids on a small scale are a few of the benefits of microfluidics that may be exploited to create customized bulk nanobubbles. However, despite the potential of microfluidic nanobubble generation, low throughput and limited nanobubble concentration remain challenging for microfluidics. Here, we integrate a microporous silicon membrane into a polydimethylsiloxane microfluidic chip to generate bulk nanobubbles in the 100-140 nm diameter range with a concentration of up to 10⁸ mL^-1. We investigate the nanobubble size and morphology using several characterisation techniques, including transmission electron microscopy, resonance mass measurement, dynamic light scattering, and the Tyndall effect. This new nanobubble generation technique can increase nanobubble concentration by ∼ 23 times compared to earlier microfluidic nanobubble generation platforms, which should increase the feasibility of translation to medical applications.

Keywords: Bubble shrinkage; Microbubble; Microfluidics; Nanobubble.