The study, published in Nature, investigates the influence of charged micrometre-sized particles on the breakdown voltage of air gaps. The presence of such particles modifies the conditions under which air ceases to behave as an insulator and an electrical discharge occurs, a phenomenon relevant both to the design of high-voltage systems and to the basic understanding of gas ionisation.

The breakdown voltage of air is a key parameter in electrical engineering: it defines the maximum potential difference that can be sustained between two electrodes separated by air before a spark or arc forms. Under clean, controlled conditions, this value is well characterised by Paschen's law, which relates the breakdown voltage to the product of gas pressure and electrode separation. However, the presence of impurities, moisture or suspended particles can significantly shift the predictions of this model.

The study quantifies how charged particles with micrometre-scale dimensions modify the breakdown voltage of air gaps. By carrying electric charge, these particles generate locally intensified fields in their immediate surroundings, facilitating the onset of electron avalanche processes at applied voltages below those expected for a clean gap. The work provides experimental data that allow the magnitude of this effect to be assessed as a function of particle characteristics.

Understanding this phenomenon matters for practical applications: in high-voltage installations, power electronics and any device relying on the dielectric strength of air, contamination by charged particles can reduce safety margins. The results offer a quantitative basis for incorporating these effects into design criteria and breakdown prediction models.