Highly Stretchable and Conductive Superhydrophobic\nCoating for Flexible Electronics

Abstract

Superhydrophobic\nmaterials integrating stretchability with conductivity have huge potential\nin the emerging application horizons such as wearable electronic sensors,\nflexible power storage apparatus, and corrosion-resistant circuits.\nHerein, a facile spraying method is reported to fabricate a durable\nsuperhydrophobic coating with excellent stretchable and electrical\nperformance by combing 1-octadecanethiol-modified silver nanoparticles\n(M-AgNPs) with polystyrene-<i>b</i>-poly­(ethylene-<i>co</i>-butylene)-<i>b</i>-polystyrene (SEBS) on a\nprestretched natural rubber (NR) substrate. The embedding of M-AgNPs\nin elastic SEBS matrix and relaxation of prestretched NR substrate\nconstruct hierarchical rough architecture and endow the coating with\ndense charge-transport pathways. The fabricated coating exhibits superhydrophobicity\nwith water contact angle larger than 160° and a high conductivity\nwith resistance of about 10 Ω. The coating not only maintains\nsuperhydrophobicity at low/high stretch ratio for the newly generated\nsmall/large protuberances but also responds to stretching and bending\nwith good sensitivity, broad sensing range, and stable response cycles.\nMoreover, the coating exhibits excellent durability to heat and strong\nacid/alkali and mechanical forces including droplet impact, kneading,\ntorsion, and repetitive stretching–relaxation. The findings\nconceivably stand out as a new tool to fabricate multifunctional superhydrophobic\nmaterials with excellent stretchability and conductivity for flexible\nelectronics under wet or corrosive environments.