Graphene-Based Sensing Skins Manufactured by Scalable and Controllable Assembly

Electronic skins have attracted extensive attention from both academic and industry as they can offer extended functions for human skin by being able to monitor various kinds of stimuli including temperature, stress/strain, humidity, light, etc. Sensors manufactured by controllable, scalable, and ultra-fast assembly of functional materials (e.g., graphene) are reported in this paper. With our innovatively designed controllable manufacturing technique, graphene does not need to be dispersed or blended with non-conductive binders. Instead, the graphene particles are randomly distributed at the surface of the skin-like substrates (i.e., medical tapes) without using any binder within a very short time (less than milliseconds). Strain sensing tests were conducted on those electronic skins, revealing that after relatively long-term tensile tests, the strain sensitivity of the electronic skin kept at a high level with good linearity, stability, and repeatability. As no binder is needed, the skin sensors were found to possess high sensitivity by a demonstration of detecting air follow pressure as low as ~2.5 Pa. Furthermore, the capability of detecting sound has been demonstrated, indicating that they can potentially act as artificial eardrums in the future.