Physical backgrounds for highly sensitive optical sensors of mechanical perturbations based on flow phenomena in
liquid crystals are presented. It is shown that linear declinations of the optical axis of a nematic liquid crystal induced by
a pressure gradient from the initial homeotropic orientation which are registered via polarized light can be considered as
the basic mechanooptical effect for sensor applications. The ways of optimization of technical characteristics of liquid
crystal sensors including usage of electric fields are discussed. The examples of sensors of acceleration, vibration and
inclination based on the same principals are considered. It is shown that usage of liquid crystals provides an extremely
high threshold sensitivity and electric control of the main technical parameters of optical sensors.