Study of bubble dynamics detaching from flexible channels

Exploring bubbles dynamics generated on flexible substrates in confined spaces is essential to achieve the potential of this configuration for two-phase flow in various engineering applications. Especially, bubble dynamics could significantly impact the heat transfer performance. This study numerically examines bubble dynamics between flexible plates with different elastic moduli to promote bubble departure. The departure time and velocity of bubbles during their motion through flexible channels are investigated and validated by experiments. An optimal elastic modulus which minimizes bubble departure time is identified. It is found that bubble dynamics with elastic plates exhibit shorter bubble departure time due to the energy conversion between kinetic energy and elastic potential energy. The plate morphology and the contact length between the bubble and elastic plates are also found to significantly affect bubble dynamics. Deformations in the plates, such as necked-in or necked-out shapes, are observed only in cases where the elastic modulus is to E ≤ 10⁷ Pa due to elastic capillary effect. A necked-out morphology helps store elastic potential energy, facilitating bubble departure. This study provides a theoretical basis and design principles for applying flexible materials in microfluidic systems.