Piezoelectric and pyroelectric properties of new polysiloxane smectic C∗ elastomers

✍ Scribed by M. Mauzac; H.-T. Nguyen; F.-G. Tournilhac; S.-V. Yablonsky

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 488 KB
• Volume: 240
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(95)00574-n

✦ Synopsis

We investigated the pyroelectric and piezoelectric effects of new smectic C * liquid crystalline elastomers. The materials are made up of a flexible polysiloxane backbone bearing chiral mesogenic side groups and are cross-linked via alkylene chains. The polar structure of the mesophase is evidenced by the observation of piezoelectric and pyroelectric effects. Integration of the pyroelectric coefficient over the whole smectic C * stability range allows the determination of the spontaneous polarization (Ps = 3-6 nC/cm').

Due to the rubber elasticity, these materials exhibit a high piezoelectric response. The piezosignal at room temperature does not vanish after annealing at temperatures even much higher than the Curie point. The piezoelectric coefficient d,, ranges from 0.5 pC/N for non-poled samples to 2.5 pC/N after application of a poling field.