Generation of water-encapsulated microbubbles (gas-in-water-in-oil) is reported using two different microfluidic geometries (double flow-focusing and flow-focusing followed by a T-junction). By adjusting the flow rate ratio of water to oil (Qw/Qo), we demonstrate the ability to control the number of encapsulated microbubbles in micron-size water droplets and the thickness of the water layer. Adding photopolymerizable monomers into the water phase, we are able to polymerize the aquesou droplets that encapsulate multi-microbubbles and obtain porous polymer microparticles. This flexible technology has the potential to generate porous microparticles with controlled properties.