Graphene, a technological device from the University of Manchester which was awarded the 2010 Nobel Prize in Physics, has been utilized to create flexible and tough water filtration devices, digital touchscreens, drug delivery systems, and enhanced night vision contact lenses. It is a veritable wonder material; just this year it has formed the basis of an additional technological innovation – a microphone almost 32 times more sensitive than standard ones. This new invention is defined in the journal 2D Materials.
The graphene membrane, a mere 30 carbon atoms thick, was cultivated on a nickel-based foil utilizing a process called CVD (chemical vapor deposition). Within CVD, reactive, gaseous materials (like methane, a compound containing carbon) interact with a substrate, (the foil), to generate graphene. Following the graphene sheets beginning to crystallize out upon the foil, the nickel carefully was removed.
Normally, microphone performance is measured and tested by recording a sequence of sound waves over a frequency range, from the low 10 hertz to the higher 24 kilohertz – around the entire hearing range. Frequency is associated with a sound’s “pitch,’ whereby the amplitude is associated with its “loudness.” Sound waves that increase in frequency yet remain at consistent amplitudes were blasted at this graphene foil.
The more the membrane’s vibration matches up with the sound wave’s wave pattern, the more sensitive its’ deemed to be. The results, as compared with regular nickel-based membranes, were amazing. It exhibited a 32-fold rise in sensitivity around a substantial portion of the audio spectrum: 11 kilohertz, around a dizzying range of amplitudes.