Signal conditioning of carbon nanotube thin film loudspeakers

Abstract

Super-aligned carbon nanotube (CNT) thin films offer the capability to be placed into compact lightweight sound sources for active noise control, loudspeaker, or other acoustic applications. The super-aligned CNT films generate thermoacoustically induced oscillations to generate sound. This occurs through the use of a dynamic signal, such as applying an alternating current in the audio frequency range to the thin film. This mechanism is carried out through joule heating which heats the air above the surface, thereby producing sound waves from periodic air vibration. Here, we report an investigation of the sound pressure and thermal properties of advanced carbon nanotube thin films with an emphasis to address the signal distortion issue.