To obtain large electrostriction (Smax) at low electric filed (Emax), a dependence of the solidification thickness (L) on Smax was investigated for polyurethane films. Thinning the films remarkably enhanced Smax at high Emax at 20MV/m, whereas thick films apparently exhibited higher Smax at low Emax of less than 3MV/m. The L dependent Smax from 5.01% for 140μm thickness to 30.99% for 28μm thickness exhibited linear relationship of pure polyurethane. Considering crystalline volume fraction and crystalline periodicity, the L dependent Smax was explained.
- Crystalline periodicity
- Electro active