Thickness strains in polyurethane films, induced by electrostatic field (-12 ÷ +12) MV/m
were measured under ambient conditions. There were found a symmetrical strain profile and
the compression along thickness for the inversion of the electric power polarity. Induced
strain shows a quadratic dependence vs. electrical field up to about 3 MV/m, suggesting the
electrostrictive nature of the strain response. Maximum induced strain (4.2 %) and an
electrostrictive coefficient of 1.7 × 10
-15 m
2
/V
2
are quite comparable to those reported in
literature on similar commercial polyurethane films. The contraction response time
(~ 4.7 × 10
3 ms) was found smaller than that of the relaxation process. An effective
compressive pressure of 0.63 MPa and a density of mechanical energy (0.013 J/cm
3
) were
obtained. The Maxwell effect contribution of only 0.12 % was found. The investigated
polyurethane offers good promise in applications such as sensors and actuators.