It is very important to understand the mechanical properties of polymers at the nanoscale with the continuing demand of decreasing the size of circuit in the electronic industry. There has been considerable research on the confinement effect in thin films with a variety of techniques, often with conflicting results. We developed the stress-strain analysis and energy balance approach to separate the surface tension contribution to the observed rubbery stiffening. Further, the geometry effect in the nanobubble inflation technique was investigated by comparing the creep behavior of circular...