Temperature Compensated Graphene Nanomechanical Resonators

Abstract

We report the experimental demonstration of temperature compensated bilayer graphene two-dimensional (2D) nanomechanical resonators operating in temperature range of 300 to 480 K. By using both microspectroscopy and scanning spectromicroscopy techniques, spatially visualized undriven thermomechanical motion is conveniently used to monitor both the resonance frequency and temperature of the device via noise thermometry while the device is photothermally agitated. Thanks to engineerable naturally integrated temperature compensation of the graphene and gold clamps that minimize variations of built-in tension in a wide temperature range, very small linear TCfs of ≈−39 and −84 ppm K⁻¹ are achieved in the graphene nanomechanical resonators. The measured TCfs are orders of magnitude smaller than those in other 2D resonant nanoelectromechanical systems (NEMS). The intricately coupled thermal tuning and strain effects are further examined, elucidating that TCf can be further improved by optimizing device dimensions, which can be exploited for engineering highly stable NEMS resonators and oscillators for signal transduction and sensing applications.