All-Graphene-Based\nHighly Flexible Noncontact Electronic Skin

Abstract

Noncontact\nelectronic skin (e-skin), which possesses superior long-range and\nhigh-spatial-resolution sensory properties, is becoming indispensable\nin fulfilling the emulation of human sensation via prosthetics. Here,\nwe present an advanced design and fabrication of all-graphene-based\nhighly flexible noncontact e-skins by virtue of femtosecond laser\ndirect writing (FsLDW). The photoreduced graphene oxide patterns function\nas the conductive electrodes, whereas the pristine graphene oxide\nthin film serves as the sensing layer. The as-fabricated e-skins exhibit\nhigh sensitivity, fast response–recovery behavior, good long-term\nstability, and excellent mechanical robustness. In-depth analysis\nreveals that the sensing mechanism is attributed to proton and ionic\nconductivity in the low and high humidity conditions, respectively.\nBy taking the merits of the FsLDW, a 4 × 4 sensing matrix is\nfacilely integrated in a single-step, eco-friendly, and green process.\nThe light-weight and in-plane matrix shows high-spatial-resolution\nsensing capabilities over a long detection range in a noncontact mode.\nThis study will open up an avenue to innovations in the noncontact\ne-skins and hold a promise for applications in wearable human–machine\ninterfaces, robotics, and bioelectronics.