Ultra-robust stretchable electrode for e-skin: in situ assembly using a nanofiber scaffold and liquid metal to mimic water-to-net interaction

Abstract

The development of stretchable electronics could enhance novel interface structures to solve the stretchability–conductivity dilemma, which remains a major challenge. Herein, we report a nano-liquid metal (LM)-based highly robust stretchable electrode (NHSE) with a self-adaptable interface that mimics water-to-net interaction. Based on the in situ assembly of electrospun elastic nanofiber scaffolds and electrosprayed LM nanoparticles, the NHSE exhibits an extremely low sheet resistance of 52 mΩ sq−1. It is not only insensitive to a large degree of mechanical stretching (i.e., 350% electrical resistance change upon 570% elongation) but also immune to cyclic deformation (i.e., 5% electrical resistance increases after 330 000 stretching cycles with 100% elongation). These key properties are far superior to those of the state-of-the-art reports. Its robustness and stability are verified under diverse circumstances, including long-term exposure to air (420 days), cyclic submersion (30 000 times), and resilience against mechanical damages. The combination of conductivity, stretchability, and durability makes the NHSE a promising conductor/electrode solution for flexible/stretchable electronics for applications such as wearable on-body physiological signal detection, human–machine interaction, and heating e-skin.