[17p-P6-1~34] 12.3 Functional Materials and Novel Devices

△ [17p-P6-34] Ferroelectric and piezoelectric characterization of P(VDF-TrFE)/ionic liquid gels

〇Miki Fukagawa¹, Yasuko Koshiba¹, Masahiro Morimoto^1,2, Tatsuya Fukushima¹, Kenji Ishida¹ (1.Kobe Univ., 2.Univ. of Toyama)

Keywords:organic ferroelectric, ionic liquid, piezoelectric

Piezoelectric gels were prepared from low-volatile ionic liquid (IL) 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim][TFSI]) gels, and their structural, ferroelectric, and piezoelectric properties were investigated. Poly(vinylidene fluoride-trifluoroethylene) P(VDF-TrFE)/IL gels were formed using thermally reversible physical gels. The structural characterization indicated that the P(VDF-TrFE) molecules in the gels predominantly formed a ferroelectric phase (Form I) of P(VDF-TrFE). Polarization switching peaks were clearly observed using a three-layer stacked device structure. The coercive field of the P(VDF-TrFE)/IL gels substantially decreased to 4–9 MV/m, and their remnant polarizations were maintained at 63–71 mC/m², which is similar to that for typical solid-state P(VDF-TrFE). Finally, the P(VDF-TrFE)/IL gel films exhibited a piezoelectric response, and the highest piezoelectric coefficient was ~300 pm/V at an applied voltage frequency of 4 kHz.