Their study focuses on the degree or level of localization in nanoscale dissipative interactions. This is typically ignored in the literature by either assuming that the dissipation occurs at a given point between the colliding bodies or by giving rough estimations of the area over which the energy is dissipated.

Figure of merit

The group, which includes scientists from institutes in the UAE, Spain, the UK and the US, calculates the effective area of interaction for each of the elementary dissipative processes. It then uses a figure of merit defined as M to quantify both the density of the energy dissipated and the level of localization of each dissipative interaction. Each process is shown to present a different pattern in M with decreasing separation between the colliding bodies from tens of nanometers to angstroms.

The work is theoretical, but uses parameters that can be readily measured with an atomic force microscope.

Predicting gas viscosity

The method could be used to predict the viscosity of different gases in nanometric confined volumes, and the team is currently exploring this idea.

More information can be found in the journal Nanotechnology.