Advances in aerosol measurement approaches are central to identifying new aerosol sources, explaining their atmospheric transformations, and quantifying their atmospheric and health impacts. Single particle mass spectrometry and super- and sub-micron droplet levitation approaches (e.g. optical tweezers, electrodynamic balances) have led to major recent advances in single particle analysis across aerosol science. Single particle mass spectrometry allows online composition analysis of individual airborne particles but additional information (e.g. particle shape, size, structure) is only rarely experimentally accessible. By contrast, droplet levitation allows time-resolved measurements of droplet physical properties (e.g. size, mass, surface tension, viscosity, structure) in response to changes in local environmental conditions but provides limited composition information.

We are pioneering new experimental approaches combining precise retrieval of an individual droplet’s physical properties with molecular level characterisation of its surface and bulk composition, directly linking physical and chemical properties and enabling surface-specific monitoring of atmospherically relevant reactions in aerosol droplets. These novel tools will have wide utility across all application areas in aerosol science.