When scientists create graphene by heating a precursor material with a laser, they usually analyse the form and quality of the finished product using techniques such as Raman spectroscopy or electron microscopy. A team at Rice University in the US has now put forward a completely new alternative: listening to the sounds produced as this laser-induced graphene grows.
The new technique arose when two students in James Tour’s lab at Rice, John Li and Victor Li, got the idea of attaching a $31 microphone to the laser writing head. After recording the sounds the graphene made as it grew, the pair, who are brothers and were aged just 19 and 17 at the time, converted these sounds into spectrograms and used a simple signal processing technique known as a fast Fourier transform to turn the patterns into interpretable signals. Thanks to this technique, members of the team were able to analyse the properties of their laser-induced graphene in real time – a significant advantage over conventional methods.
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