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 graphenebased 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.

Integrating multifunctional semiconducting metal oxide powders into a 3D printing technique to construct hierarchical porous structures is highly desirable and remains a significant challenge. Herein, an extrusion‐based 3D printing strategy is developed that can assemble TiO2 powders into hierarchical porous structures with multiscale pores at both the macro‐ and microscale. Powder‐based TiO2 inks with a significant shear‐thinning behavior and adequate storage modulus and yield stress are developed to meet the requirements of 3D printing of TiO2 in an air environment without the need for an additional solidification treatment, which provides good printing flexibility. The hierarchical porous structures with a relatively high compressive strength provide the 3D‐printed TiO2 structures with great potential for use in many applications, including filtration, thermal insulation, biomedical scaffolds, catalyst supports, and energy conversion. Compared with scaffolds with a compact morphology, the hierarchical porous TiO2 scaffold as a photoelectrode achieves a higher nitrogen photofixation yield due to its high surface adsorption and activation capacity caused by its porous morphology. Importantly, the powder‐based ink design and extrusion‐based 3D printing approach are readily extended to other semiconducting metal oxides such as ZnO and their composites.

No abstract

The development of mutually reinforcing solar‐driven interfacial evaporation (SDIE) and integrated functional materials/systems to achieve efficient production of freshwater and energy/matters simultaneously under extremely high solar utilization is in high demand. Herein, an integrated SDIE reaction system (reduced graphene oxide (rGO)‐palladium (Pd) catalytic evaporator, rGO‐Pd) is first reported, where SDIE and the integrated catalytic reaction are mutually reinforced. The apparent utilization of solar to thermal energy by the integrated SDIE reaction system is a combination of evaporative utilization and catalytic utilization. The reaction heat released by the rGO‐Pd catalytic evaporator enhances its anti‐salt water production performance to a record of 12.7 L m−2 h−1, surpassing the reported performance of other integrated SDIE reaction systems. In the rGO‐Pd catalytic evaporator, the synergetic effect of photothermal and rapid mass transfer significantly increases the catalytic activity (turnover frequency) of Pd catalysts up to a record 125.07 min−1, which is about 3.75 times of the condition without light. This integrated SDIE reaction system can effectively and simultaneously produce freshwater, salt, and catalyzed chemicals after evaporating water to dryness. This study paves the way for SDIE's high‐performance applications in future integrated water, energy, and environmental systems.