Flexible pressure sensors as electronic skins have attracted wide attention to their potential applications for healthcare and intelligent robotics. However, the tradeoff between their sensitivity and pressure range restricts their practical applications in various healthcare fields. Herein, a cost‐effective flexible pressure sensor with an ultrahigh sensitivity over an ultrawide pressure‐range is developed by combining a sandpaper‐molded multilevel microstructured polydimethylsiloxane and a reduced oxide graphene film. The unique multilevel microstructure via a two‐step sandpaper‐molding method leads to an ultrahigh sensitivity (2.5–1051 kPa−1) and can detect subtle and large pressure over an ultrawide range (0.01–400 kPa), which covers the overall pressure regime in daily life. Sharp increases in the contact area and additional contact sites caused by the multilevel microstructures jointly contribute to such unprecedented performance, which is confirmed by in situ observation of the gap variations and the contact states of the sensor under different pressures. Examples of the flexible pressure sensors are shown in potential applications involving the detection of various human physiological signals, such as breathing rate, vocal‐cord vibration, heart rate, wrist pulse, and foot plantar pressure. Another object manipulation application is also demonstrated, where the material shows its great potential as electronic skin intelligent robotics and prosthetic limbs.

Along with the progress of nanoscience and nanotechnology, nanomaterials with attractive structural and functional properties have gained more attention than ever before, especially in the field of electronic sensors. In recent years, the gas sensing devices have made great achievement and also created wide application prospects, which leads to a new wave of research for designing advanced sensing materials. There is no doubt that the characteristics are highly governed by the sensitive layers. For this reason, important advances for the outstanding, novel sensing materials with different dimensional structures including 0D, 1D, 2D, and 3D are reported and summarized systematically. The sensing materials cover noble metals, metal oxide semiconductors, carbon nanomaterials, metal dichalcogenides, g‐C3N4, MXenes, and complex composites. Discussion is also extended to the relation between sensing performances and their structure, electronic properties, and surface chemistry. In addition, some gas sensing related applications are also highlighted, including environment monitoring, breath analysis, food quality and safety, and flexible wearable electronics, from current situation and the facing challenges to the future research perspectives.

Highly sensitive and stable gas sensors have attracted much attention because they are the key to innovations in the fields of environment, health, energy savings and security, etc. Sensing materials, which influence the practical sensing performance, are the crucial parts for gas sensors. Metal-organic frameworks (MOFs) are considered as alluring sensing materials for gas sensors because of the possession of high specific surface area, unique morphology, abundant metal sites, and functional linkers. Herein, four kinds of porous hierarchical CoO structures have been selectively controlled by optimizing the thermal decomposition (temperature, rate, and atmosphere) using ZIF-67 as precursor that was obtained from coprecipitation method with the co-assistance of cobalt salt and 2-methylimidazole in the solution of methanol. These hierarchical CoO structures, with controllable cross-linked channels, meso-/micropores, and adjustable surface area, are efficient catalytic materials for gas sensing. Benefits from structural advantages, core-shell, and porous core-shell CoO exhibit enhanced sensing performance compared to those of porous popcorn and nanoparticle CoO to acetone gas. These novel MOF-templated CoO hierarchical structures are so fantastic that they can be expected to be efficient sensing materials for development of low-temperature operating gas sensors.