Heath M S, Horsell D W
School of Physics and Astronomy, University of Exeter, Stocker Road, Exeter, EX4 4QL, UK.
Sci Rep. 2017 May 2;7(1):1363. doi: 10.1038/s41598-017-01467-z.
The ability to generate, amplify, mix and modulate sound in one simple electronic device would open up a new world in acoustics. Here we show how to build such a device. It generates sound thermoacoustically by Joule heating in graphene. A rich sonic palette is created by controlling the composition and flow of the electric current through the graphene. This includes frequency mixing (heterodyning), which results exclusively from the Joule mechanism. It also includes shaping of the sound spectrum by a dc current and modulating its amplitude with a transistor gate. We show that particular sounds are indicators of nonlinearity and can be used to quantify nonlinear contributions to the conduction. From our work, we expect to see novel uses of acoustics in metrology, sensing and signal processing. Together with the optical qualities of graphene, its acoustic capabilities should inspire the development of the first combined audio-visual nanotechnologies.
在一个简单的电子设备中实现声音的产生、放大、混合和调制，将为声学领域开辟一个全新的世界。在此，我们展示了如何构建这样一种设备。它通过石墨烯中的焦耳热以热声方式产生声音。通过控制流经石墨烯的电流的成分和流量，可以创造出丰富的音色库。这包括频率混合（外差法），这完全是由焦耳机制产生的。它还包括通过直流电流对声谱进行整形，以及用晶体管栅极调制其幅度。我们表明，特定的声音是非线性的指标，可用于量化对传导的非线性贡献。基于我们的工作，我们期望看到声学在计量学、传感和信号处理中的新应用。连同石墨烯的光学特性，其声学能力应能激发首个视听一体化纳米技术的发展。
