Transparent and flexible GnP/PVDF/GnP composites film speaker

Abstract

In the mobile IT industries, the miniaturization, slimming and lower electric power developed rapidly with the appearance of smart phone and tablet PC. The acoustic research faces this technical turning point for corresponding to the request of this system. There is the microphone which is sensor for converting sound to electric signal with the representative sound element, and the speaker and actuator can change the electrical energy to sound. This is the important component for controlling the quality of the audio products. Recently, the new products, like the micro type MEMS microphone and ultra thin piezoelectric loudspeaker, attract attention in the market. Transparent thin film acoustic actuators and sensors have many other diverse applications. For instance, thin film speakers can work as transparent compact and lightweight general purpose flat panel loudspeakers. An electro-acoustic loudspeaker was developed by using the electro acoustic response of a polymer thin film. The high resonant frequency and required high driving electric field sill prohibit its use from most normal loudspeaker applications. Piezoelectric PVDF (poly (vinylidene fluoride)) has been investigated to fabricate acoustic transducers, either being used as a sensor. The developed nano graphene platelets (GnP) based transparent thin film acoustic transdure showed excellent acoustic response. Interfacial and electrical durability of GnP/PVDF/GnP composites were investigated for acoustic actuator applications. Durability on the interfacial adhesion was good for GnP/PVDF/GnP composites. In this research, the electrical characteristic of CNT, ITO and GnP nanocomposites was measured by using surface resistance test. The contact angle was measured and the interfacial property was evaluated in the speaker system. In addition, the frequency, voltage and sound characteristics according to the content of the GnP were evaluated. Copyright © (2012) by Asian-Australasian Association for Composite Materials (AACM).