Nanocatalysts induced self-triggering leather skin for human–machine interaction

• A novel ionically conductive leather skin is developed by in-situ self-triggering gelation of ionogels in the hierarchical structure of leather matrix. • The liquid metal@catechin nanocatalysts enable rapid and uniform gelation under ambient conditions. • The leather skin shows excellent ionic conductivity, mechanical properties, air permeability, water vapor permeability, and wide temperature tolerance. • A bionic glove can be developed based on leather skin as gesture-discernible wearable controller for human-machine interaction. Electronic skins mimicking the comprehensive functions of human skin are highly interesting for the development of human-machine interactions (HMI). Conventional conductive leathers face challenges of the non-uniform dispersion of conductive components and the complicated fabrication processes, hindering their applications for electronic skins. Herein, a novel ionically conductive leather skin is developed by in-situ self-triggering gelation of ionogel in the hierarchical structure of leather matrix. The core-shell structured liquid metal@catechin nanocatalysts enable rapid and uniform gelation within tens of seconds under ambient conditions. Resulting interpenetrating ionogel networks within leather matrix not only provides 3D continuous and highly conductive pathways for ionic transport, but also forms multiple bonding for strong interfacial interactions. These advantageous properties endow leather skin with excellent mechanical robustness (tensile stress:17.8 MPa; toughness: 1590 kJ/m 3 ), high air transmission rate (720 mL/cm 2 /h) and water vapor transmission rate (70 g/m 2 /h), as well as broad environmental tolerance (-80∼100 °C). Impressively, the leather skin-based sensors exhibit stable and fast response with only 40 ms. The attractive performances of leather skin are further demonstrated by a bionic glove as a gesture-discernible wearable controller for HMI. This work opens up a new horizon for developing the ionically conductive leather skin, which will have profound implications for wearable electronic systems.