Researchers at the University of Belgrade in Serbia have made the first graphene-based “condenser” microphone that could work at ultrasonic frequencies. The device, which outperforms state-of-the-art commercial nickel-based microphones over a large part of the acoustic spectrum, could find use in a variety of applications – such as monitoring bats, whales and other animals that communicate via ultrasound…..
http://nanotechweb.org/cws/article/tech/63444