Graphene microphone 32 times more sensitive developed

Scientists have developed a graphene based microphone nearly 32 times more sensitive than microphones of standard nickel-based construction.
Researchers at the University of Belgrade in Serbia created a vibrating membrane - the part of a condenser microphone which converts the sound to a current - from graphene, and were able to show up to 15 decibels (dB) higher sensitivity compared to a commercial microphone, at frequencies up to 11 kilohertz (kHz).
"We wanted to show that graphene, although a relatively new material, has potential for real world applications. Given its light weight, high mechanical strength and flexibility, graphene just begs to be used as an acoustic membrane material," said Marko Spasenovic, from University of Belgrade.

The graphene membrane, approximately 60 layers thick, was grown on a nickel foil using chemical vapour deposition, to ensure consistent quality across all the samples.
During membrane production, the nickel foil was etched away and the graphene membrane placed in the same housing as a commercial microphone for comparison. This showed a 15 dB higher sensitivity than the commercial microphone.
The researchers also simulated a 300-layer thick graphene membrane, which shows potential for performance far into the ultrasonic part of the spectrum.
"The microphone performed as well as we hoped it would. The industry is working hard to improve graphene production - eventually this should mean we have better microphones at lower cost," Spasenovic said.

The study was published in the journal 2D Materials.