We have fabricated PU elastomer shell particles by using the microfluidic technology. This capsule structure led to improved protection function as well as controlled deformation. Especially, when osmotic pressure was applied to the particles, the shell layer was deformed with a different pattern, which depended on the phase property of the core materials. The water-filled core showed indentation; however, the hydrogel-filled core showed surface buckling. This work is done by Sang Woo. Excellent!!!