Beyond Skin Pressure Sensing: 3D Printed Laminated Graphene Pressure Sensing Material Combines Extremely Low Detection Limits with Wide Detection Range

Artificial intelligence robots predicted in sci-fi movies have attracted increasing attention in recent years, and much effort has been devoted to improving the sensing and manipulation performance of robots. The development of robotic skins capable of handling complex external pressure environments is highly desired for intelligent robots. However, this remains a major challenge due to the lack of pressure sensing materials that can combine extremely low detection limits and wide detection ranges. Inspired by the synergistic strategy of dual mechanoreceptors in human skin, here, the design and 3D printing of laminated graphene pressure sensing materials consisting of both ultrathin- and thick-walled cellular microstructures are demonstrated. Based on such laminated graphene, the piezoresistive pressure sensor achieves a low detection limit of 1 Pa, a wide detection range (1 Pa-400 kPa), and high sensitivities of 3.1 and 0.22 kPa(-1) in the pressure regions of 1 Pa-13 kPa and 13-400 kPa, respectively, and the laminated graphene-based skin enables quantitative pressure/weight detection. This laminated graphene can be easily integrated into flexible pressure sensing arrays that enable mapping the spatial distribution of pressure, showing great potential for applications such as electronic skin, physiological signal monitoring, and human-machine interfaces.