Flow Conductance of a Single Nanohole

TL;DR

This study measures the flow conductance of single nanoholes, revealing a transition from effusion to viscous flow as the mean free path matches the nanohole size, and observes deviations from classical Poiseuille behavior.

Contribution

It provides experimental data on nanohole conductance across flow regimes and highlights the crossover point related to mean free path matching nanohole diameter.

Findings

Crossover from effusion to viscous flow observed.

Breakdown of Poiseuille approximation in temperature dependence.

Flow behavior depends on nanohole size and gas mean free path.

Abstract

The mass flow conductance of single nanoholes with diameter ranging from 75 to 100 nm was measured using mass spectrometry. For all nanoholes, a smooth crossover is observed between single-particle statistical flow (effusion) and the collective viscous flow emanating from the formation of a continuum. This crossover is shown to occur when the gas mean free path matches the size of the nanohole diameter. As a consequence of the pinhole geometry, the breakdown of the Poiseuille approximation is observed in the power-law temperature exponent of the measured conductance.