Wrinkle-enabled hydrophobic underwater stable ionic skin with unique positive resistance effect

Flexible ionic conducting elastomers are ideal electronic material for human–computer interaction and movement monitoring due to their high electrical conductivity and excellent stretchability. However, ionic-based flexible materials are susceptible to evaporation and leakage of ions in harsh environments and exhibit a negative resistance effect, limiting the application scenarios for electronic devices. Herein, an ionic-based conductive elastomer with high toughness and excellent hydrophobicity was fabricated based on the interaction system between fluorine-rich main segment and [EMIM]+ in the polyurethane backbone, a unique wrinkles structure is formed on the surface of the sensor. During the stretching process, wrinkles are gradually released and promote the movement of free ions, resulting in a significant positive resistance effect on the ionic-based conductive elastomers. Importantly, the cations captured by the polyurethane backbone are difficult to diffuse into the water interface, which is the key point to the underwater stabilization of ionic conductivity. It is believed that this flexible ionic-based sensor possesses broad application prospects in various applications such as wearable devices and human–computer interaction.