Piezoelectric paper speaker using a regenerated cellulose film

Acoustic performance of regenerated cellulose electroactive paper (EAPap) as a thin flexible film speaker was investigated. The enhancement of piezoelectric properties was obtained by a simple mechanical stretching process. As a prototype of flexible paper speaker, the sound pressure level (SPL) of cellulose EAPap film was evaluated as a function of distance, speaker size and geometry. It was revealed that the higher acoustic output from a small rectangular shape in low frequency range, while circular one seems to be better than that of all rectangular type speakers in audible frequencies.