The press release didn't mention it at all. This figure shows three possibilities: https://www.nature.com/articles/s41928-024-01174-4/figures/4

* Augmented touch perception via dual-ECG sensing with person-i wearing bioelectronic fibre arrays and person-ii without. * A breathable skin-gated OECT on a fingertip * Dual-modal sensing for augmented perception of mist pulses with acidic, alkaline and neutral compositions distinguished through colorimetric and electrical readouts.

That is amazing.