Study of Heat Transfer of Gas Flow Heated by Nano-Probe via Direct Stimulation Monte Carlo (DSMC)

Applications of heated tip/surface configuration for micro-/nano-electromechanical systems (MEMS/NEMS) have been widely explored in these years. Since the small gaps in these MEMS/NEMS are comparable to the mean free path of gaseous molecules, the heat transfer via gaseous molecules from the heated tip to the substrate is fundamentally different from macroscopic conduction or convection heat transfer in gases. In this paper, the heat transfer of the rarefied gases heated by hot nano-tip is investigated by means of the Direct Simulation Monte Carlo (DSMC) method. The results show that both tip geometry and tip-substrate distance affect the heat flux density distribution. With the increase of the crossing-angle θ of the nano-tip, the heat flux tends to decrease, while the spatial resolution tends to improve. Moreover, the heat flux density and spatial resolution tend to decrease with the increase of distance between the nano-tip and the substrate. Simulation results provide valuable information for the rational design and optimization of the heated nano-probe for topography applications such as thermally assisted data storage.