AbstractA ferroelectric device, making use of a flexible plastic, polyethylenterephtalate (PET), as a substrate was fabricated by all solution processes. PET was globally coated by a conducting polymer, poly(3,4‐ethylenedioxythiophene) poly(styrenesulfonate) acid (PEDOT/PSSH), which is used as bottom electrode. The ferroelectric copolymer, poly(vinylidenefluoride–trifluoroethylene) (PVDF–TrFE), thin film was deposited by spin‐coating process from solution. The top electrode, polyaniline, was coated by solution process as well. The ferroelectric properties were measured on this all solution processed all polymer ferroelectric thin‐film devices. A square and symmetric hysteresis loop was observed with high‐polarization level at 15‐V drive voltage on a all polymer device with 700 Å (PVDF–TrFE) film. The relatively inexpensive conducting polyaniline electrode is functional well and therefore is a good candidate as electrode material for ferroelectric polymer thin‐film device. The remnant polarization Pr was 8.5 μC/cm2 before the fatigue. The ferroelectric degradation starts after 1 × 103 times of switching and decreases to 4.9 μC/cm2 after 1 × 105 times of switching. The pulse polarization test shows switching take places as fast as a few micro seconds to reach 90% of the saturated polarization. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011