Flexible and transparent organic film speaker by using highly conducting PEDOT/PSS as electrode

Flexible organic film speaker (FOFS) was fabricated with ion-assisted-reaction (IAR) treated poly(vinylidene fluoide) (PVDF) as active layer and poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), indium tin oxide (ITO), or copper (Cu) as electrode. The PEDOT/PSS materials were screen printed on the PVDF surface. The dc conductivity (sigma(dc)) of pristine PEDOT/PSS increases from 0.8 to similar to80 S/cm by adding various organic solvents. The sound pressure level (SPL) of PVDF-based FOFS with a highly conducting PEDOT/PSS (dimethyl sulfoxide, DMSO) electrode is 27 dB higher than that with a low conducting PEDOT/PSS (H2O) at 1 kHz. The highly conducting PEDOT/PSS (DMSO) as electrode is more suitable to PVDF-based FOFS compared to Cu or ITO because of the stable and more flat SPL, the flexibility, easy patterning, and coating process. (C) 2003 Elsevier Science B.V. All rights reserved.