Oscillators, which produce continuous periodic signals from direct current power, are central to modern communications systems, with versatile applications including timing references and frequency modulators. However, conventional oscillators typically consist of macroscopic mechanical resonators such as quartz crystals, which require excessive off-chip space. Here, we report oscillators built on micrometre-size, atomically thin graphene nanomechanical resonators, whose frequencies can be electrostatically tuned by as much as 14%. Self-sustaining mechanical motion is generated and transduced at room temperature in these oscillators using simple electrical circuitry. The prototype graphene voltage-controlled oscillators exhibit frequency stability and a modulation bandwidth sufficient for the modulation of radiofrequency carrier signals. As a demonstration, we use a graphene oscillator as the active element for frequency-modulated signal generation and achieve efficient audio signal transmission.
Bibliographical noteFunding Information:
The authors thank P. Kim, J. Kymissis, A. van der Zande, N. Petrone, A. Gondarenko, E. Hwang, C. Lee, A. Molnar and V. Abramsky for discussions. Fabrication was performed at the Cornell Nano-Scale Facility, a member of the National Nanotechnology Infrastructure Network, which is supported by the National Science Foundation (grant ECS-0335765), and the Center for Engineering and Physical Science Research (CEPSR) Clean Room at Columbia University. The authors acknowledge support from the Qualcomm Innovation Fellowship (QInF) 2012 and AFOSR MURI FA9550-09-1-0705. G.H.L. acknowledges support from Samsung-SKKU Graphene Center.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics
- Biomedical Engineering
- Materials Science(all)
- Condensed Matter Physics
- Electrical and Electronic Engineering