Multiphase flows in confined geometries exhibit a variety of intriguing morphologies. At the
small scale, the unique balance of forces produces flow patterns that are typically governed
by viscous and capillary effects. While surface tension tends to minimize liquid-gas
interfacial areas with bubbles having spherical shape, viscous creeping flows can also
strongly deform bubbles in velocity fields set with the channel geometry. Here, the
deformation of capillary surfaces is accentuated with the use of a highly viscous carrier fluid …