Graphene in Loudspeaker Membrane

Purpose and goal

The project aimed to develop a self-standing composite membrane made of graphene oxide and nanocellulose for high-end speakers and tweeters. After selecting suitable raw materials, flat membrane prototypes were designed and characterized, and then integrated into speaker drivers for testing. The translation into dome-shaped membranes was also investigated, and evaluations were conducted with driver manufacturers. Potential challenges in upscaling were discussed with external partners.

Expected results and effects

The main results from this project were that, despite displaying promising features for speaker membranes, composites made of nanocellulose and graphene oxide are difficult to produce to meet the specifications that grant integration in drivers. Owing to the 2D nature of graphene and to a wet process, defect management remains an issue that affect domes quality, even of moderate size (e.g. tweeters). The integration of graphene/nanocellulose in the form of a coating is a potential alternative that would require significant adjustments to the current production line.

Planned approach and implementation

The project plan had high ambitions and aimed at possible integration of the membrane within commercial systems within the course of the project. From a dome production perspective, a number of limitations have been encountered, impacting this aspect of the project, even on the performance evaluation side. We had to identify potential external partners to complement the expertise of the working group, and to learn to integrate our formulation within their materials. In conjunction with the pandemic situation, it took considerable time to manage some aspects of the project.