The traditional notion of tattoos as a form of human self-expression is rapidly expanding its boundaries, penetrating spheres that previously seemed like science fiction plots. Today, the art of applying functional circuits to living tissue finds unexpected applications in big science and global ecology. A group of researchers from The University of Texas at Austin has presented a revolutionary development – graphene “electronic tattoos” for plant leaves. These ultra-thin sensors can monitor the moisture level in a plant in real-time, without disrupting its natural processes or harming biological tissues.