Trapping and control of bubbles in various microfluidic applications

Abstract

Active and passive techniques for bubble trapping and control in various microfluidic applications.

Microfluidic Generation of Monodisperse Nanobubbles by Selective Gas Dissolution

“…[51] We obtain a maximum NB generation frequency of 10 5 s −1 with a gas pressure of 15 psi and a liquid flow rate of 3 mL hr −1 , which leads to a final bubble concentration of ≈10 8 mL −1 . Further scale-up of the production throughput is possible by optimizing the microfluidic design, employing higher flow rates and gas pressures, parallelizing flow-focusing orifices, [52] and concentrating MBs with microcavity trapping structures, [53] followed by subsequent shrinkage to NBs. Importantly, this method generates NBs without significant changes to typical microfluidic bubble preparation methods, and without needing to improve the manufacturing resolution of microfluidic devices.…”

Micro/Nanofluidic‐Enabled Biomedical Devices: Integration of Structural Design and Manufacturing

“…Traditional trapping techniques are another form of fluid manipulation and include electrical, optical, thermal, magnetic, and acoustic. [ 105 ] Figure 7F shows a device using an automated fluid flow for the fine manipulation of micro‐ and nanoscale particles and particle trapping. [ 106 ] This flow control device consists of a fluidic layer (red) and a control layer (black).…”

Acoustic bubble for spheroid trapping, rotation, and culture: a tumor-on-a-chip platform (ABSTRACT platform)

“…As an emerging tool in fluids and cell manipulation, acoustic bubbles in microfluidics show the possibility to address the challenges above. 16,17 In low-frequency acoustic fields, bubbles can be remotely excited to act as pumps, 18,19 mixers, 20,21 switches, 22 sorters 14,23 and transporters 24 in various lab-on-a-chip (LOC) applications. Acoustic bubbles can generate secondary radiation force (SRF) on cells at a specific frequency range, which could be harnessed to trap and rotate cells on the bubble surface when the radiation force exceeds the external drag forces.…”

“…In microfluidic devices, the location of the bubbles can be precisely controlled by both active and passive methods, making it possible to trap cells and particles in desired locations. 17 Additionally, it is shown that the acoustic bubble is biocompatible in manipulating tumor cells and microorganisms, which could help maintain cell viability. 26,27 These above advantages make the acoustic bubble a promising candidate for CTC-processing.…”