First, we stress again that once the compressed amphiphile monolayer is formed, the monolayer is tensionless but shows the tendency to resist certain changes in its curvature. This is because for the compressed monolayer, although a general deformation of monolayer involves both a change of area and curvature, the further change of monolayer area would become energetic unfavorable. Since the compressed monolayer can also deform more easily in the bending modes, the interfacial free energy of the nanobubble is dominated by the curvature free energy.