Thermal Transport Measurement in Photothermal Graphene Nanomechanical Resonator

Photothermal graphene resonant sensors hold significant promise for micromechanical sensing due to their superior mechanical and thermal properties. This study investigates the resonant and thermal behaviors of graphene resonators under varying optical power and temperature conditions. We measured the thermal time constants of five-layer (5L), eight-layer (8L), ten-layer (10L) graphene resonators, observing increases by 71, 74, and 57 ns, respectively, as optical power increased from 1 to 5 mW, alongside temperature rises in the graphene films. Additionally, the corresponding thermal and mechanical properties were further examined across different ambient temperatures. Results show that the resonant frequency increases with temperature-induced surface tension, while increased tension enhances Umklapp scattering among phonons, reducing thermal conductivity. This work lays the groundwork for utilizing photothermal graphene resonators in mechanical sensing applications.