  Straining graphene results in the appearance of a pseudo-magnetic field which
alters its local electronic properties. Applying a pressure difference between
the two sides of the membrane causes it to bend/bulge resulting in a resistance
change. We find that the resistance changes linearly with pressure for bubbles
of small radius while the response becomes non-linear for bubbles that stretch
almost to the edges of the sample. This is explained as due to the strong
interference of propagating electronic modes inside the bubble. Our
calculations show that high gauge factors can be obtained in this way which
makes graphene a good candidate for pressure sensing.
