Credit: © 2007 AAAS

Shrinking microelectromechanic systems down to the nanoscale could lead to new devices with applications ranging from information processing to molecular sensing. One example of a well-studied nanoelectromechanical system is a resonator, in which a thin beam of nanosized dimensions vibrates in response to an applied force.

Now, Paul McEuen and co-workers1 from Cornell University and Pomona College in the USA have taken this concept to the limit by building a nanoresonator comprising a beam just one layer of atoms thick — a single graphene sheet. Devices were made by peeling graphene layers from graphite above trenches defined in a silicon oxide surface. Various beam thicknesses were studied, ranging from a single atomic sheet to multilayers up to 75 nm thick. The resonators could be made to vibrate electrically, by applying an oscillating voltage, or optically, by pulsing them with a laser. Resonant frequencies ranging from 1–170 MHz were observed.

The use of graphene sheets — with their high strength, low mass and large surface area — as the beams in nanoelectromechanical resonators may lead to ultrasensitive detectors of mass, force and charge. Room-temperature charge sensitivity of one of the resonators was demonstrated to be high, with better performance — expected to rival single-electron transistor devices — predicted for lower temperatures.