US Patent 9621997 Electroacoustic transduction film

Disclosed is an electroacoustic transduction film suitable for a flexible speaker or the like, in which predetermined acoustic properties are able to be stably exhibited regardless of a bending state. The electroacoustic transduction film includes a polymer composite piezoelectric body in which piezoelectric body particles are dispersed in a viscoelastic matrix formed of a polymer material having viscoelasticity at a normal temperature, and electrode layers interposing the polymer composite piezoelectric body therebetween, and an area fraction of the piezoelectric body particles in a contact surface with respect to the electrode layer is less than or equal to 50%, and thus the object is attained.