Urchinlike CuO modified by reduced graphene oxide (rGO) was synthesized by a one-pot microwave-assisted hydrothermal method. The as-prepared composites were characterized using various characterization methods. A humidity sensor based on the CuO/rGO composites was fabricated and tested. The results revealed that the sensor based on the composites showed much higher impedance than pure CuO. Compared with the sensors based on pristine rGO and CuO, the sensor fabricated with the composites exhibited relatively good humidity-sensing performance in terms of response time and response value. The humidity-sensing mechanism was also briefly introduced. The enlargement of the impedance and improvement of the humidity-sensing properties are briefly explained by the Schottky junction theory.

Real‐time detection and differentiation of diverse external stimuli with one tactile senor remains a huge challenge and largely restricts the development of electronic skins. Although different sensors have been described based on piezoresistivity, capacitance, and triboelectricity, and these devices are promising for tactile systems, there are few, if any, piezoelectric sensors to be able to distinguish diverse stimuli in real time. Here, a human skin‐inspired piezoelectric tactile sensor array constructed with a multilayer structure and row+column electrodes is reported. Integrated with a signal processor and a logical algorithm, the tactile sensor array achieves to sense and distinguish the magnitude, positions, and modes of diverse external stimuli, including gentle slipping, touching, and bending, in real time. Besides, the unique design overcomes the crosstalk issues existing in other sensors. Pressure sensing and bending sensing tests show that the proposed tactile sensor array possesses the characteristics of high sensitivity (7.7 mV kPa−1), long‐term durability (80 000 cycles), and rapid response time (10 ms) (less than human skin). The tactile sensor array also shows a superior scalability and ease of massive fabrication. Its ability of real‐time detection and differentiation of diverse stimuli for health monitoring, detection of animal movements, and robots is demonstrated.

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Softening of piezoelectric materials facilitates the development of flexible wearables and energy harvesting devices. However, as one of the most competitive candidates, piezoelectric ceramic-polymer composites inevitably exhibit reduced power-generation capability and weak mechanical strength due to the mismatch of strength and permittivity between the two phases inside. Herein a flexible, air-permeable, and high-performance piezoceramic textile composite with a mechanically reinforced hierarchical porous structure is introduced. Based on a template-assisted sol-gel method, a three-order hierarchical ceramic textile is constructed by intertwining submillimeter-scale multi-ply ceramic fibers that are further formed by twisting micrometer-scale one-ply ceramic fibrils. Theoretical analysis indicates that large mechanical stress can be easily induced in the multi-order hierarchical structure, which greatly benefits the electrical output. Fabricated samples generate an opencircuit voltage of 128 V, a short-circuit current of 120 µA, and an instantaneous power density of 0.75 mW cm −2 , much higher than the previously reported works. The developed multi-order and 3D-interconnected piezoceramic textile shows satisfactory piezoelectricity (d 33 of 190 pm V −1 ), air permeability (45.1 mm s −1 ), flexibility (Young's modulus of 0.35 GPa), and toughness (0.125 MJ m −3 ), collectively. The design strategy of obtaining balanced properties promotes the practicality of smart/functional materials in wearables and flexible electronics.