A T-junction device allowing for two simultaneous orthogonal views: application to bubble formation and break-up

Abstract

A novel design for the classical microfluidic device known as T-junction is proposed with the purpose of obtaining a simultaneous measurement of the in-plane velocity components in two orthogonal planes. A crucial feature of the proposed configuration is that all three velocity components are available along the intersection of the two planes. A dedicated optical set-up is developed to convey the two simultaneous views from the orthogonal planes into the sensor of a single camera, where a compound image is formed showing on either half one of the two views. A commercial micro-particle image velocimetry system is used to measure the velocity in the two planes. Feeding the T-junction with a liquid continuous phase and a dispersed gas phase, the velocity is measured by phase averaging along the bubble formation and break-up process showing the potentialities of the new design. The accuracy analysis shows that the error is dominated by a systematic component due to the thickness of the measurement slice. The error can be reduced by applying confocal microscopy to the present system with no further modifications so as to reduce the thickness of the measurement slab thereby reducing the error. Moreover, by sweeping the planes across the region of interest, a full three-dimensional reconstruction of the velocity field can be readily obtained. Finally, the simultaneous views offer the possibility to extract the principal curvatures of the bubble meniscus thereby providing access to the Laplace pressure.

A Microfluidic Platform for Cavitation-Enhanced Drug Delivery

“…Cell cultures can be grown within these platforms with biologically relevant features, reproducing the complexity of an organ in terms of microenvironment and 3D organisation, even including physiological levels of pressure, shear stress and dynamical mechanical stimuli [15,16]. The thorough characterisation of the physical parameters related to device geometry [17,18] allows system optimisation to favour cell growth and molecular delivery. For these reasons, these platforms allow to perform molecular, pharmaceutical, diagnostic or high-throughput analyses in controlled and reproducible conditions [18][19][20][21].…”

Numerical simulation on dynamic behaviors of bubbles flowing through bifurcate T-junction in microfluidic device*

“…As mentioned above, extensive efforts have been devoted to the study of bubble behaviors in bifurcate T-junction and plenty of valuable results have been obtained. [30][31][32][33] However, most of the existing studies focused on the behaviors of one bubble at the T-junction [34] dominated by the viscous force from the continuous phase. The continuous bubble stream which is more commonly encountered in practical application is less considered, especially in the numerical simulation work.…”