According to embodiments of the present invention, a distributed pressure
and shear stress sensor includes a flexible substrate, such as PDMS, with
a waveguide formed thereon. Along the waveguide path are several Bragg
gratings. Each Bragg grating has a characteristic Bragg wavelength that
shifts in response to an applied load due to elongation/compression of
the grating. The wavelength shifts are monitored using a single input and
a single output for the waveguide to determine the amount of applied
pressure on the gratings. To measure shear stress, two flexible
substrates with the waveguide and Bragg gratings are placed on top of
each other such that the waveguides and gratings are perpendicular to
each other. To fabricate the distributive pressure and shear sensor, a
unique micro-molding technique is used wherein gratings are stamped into
PDMS, for example.