Regenerated silk fibroin (RSF), isolated from Bombyx mori cocoons, is an abundant, cheap and sustainable natural protein. RSF hydrogels are potentially applied in various fields, however, RSF hydrogels cannot simultaneously achieve high strength and high toughness. Adopting a double network (DN) strategy, RSF-based fully physical DN gels demonstrated integrated high mechanical properties, which could be used as strain sensors, touch screen pens and electronic skins of artificial robots.