Mechanical perturbation applied on freely suspended smectic films

We apply a mechanical perturbation in the plane of the smectic layers of a free standing film by the means of modulation of the film's length. Experiments have been performed on films of different thicknesses in the liquid-like, hexatic and crystal-like smectic phases present in 70.7. We show that the meniscus is crucial for understanding the mechanical properties and that the tilt angle of the molecules in the SmG phase is one more degree of freedom for the film to respond to the perturbation