Carbon nanotube as a new coating material for developing two dimensional speaker systems

Abstract

A speaker is a two-port audio system which produces sound through electromechanical operations. It transforms electric voltage signals into audible sound signals. Almost all speakers available are three dimensional. These days, many mobile electronic devices such as mobile phones have become smaller and thinner. A problem with this miniaturization, however, is that the volume of the speakers has also decreased. In contrast to conventional three dimensional speakers, there have been several attempts to develop two dimensional speakers using piezoelectric materials. The main parts have been piezoelectric films, conductive macromolecular coating materials, and electrodes. An improved material that have been used is that used indium tin oxide in place of conductive macromolecular coating materials. We have invented a new type of two dimensional flexible speaker by applying carbon nanotube in order to replace indium tin oxide. The speaker system we have designed shows outstanding advantages, such as flexibility, wide ranges of operating frequencies, and low values impedance values, and stability. © 2011 Springer-Verlag Berlin Heidelberg.