Human-robot interface (HRI) electronics are critical for realizing robotic intelligence. Here, we report graphene-based dual-function acoustic transducers for machine learning-assisted human-robot interfaces (GHRI). The GHRI functions both an artificial ear through the triboelectric acoustic sensing mechanism and an artificial mouth through the thermoacoustic sound emission mechanism. The success of the integrated device is also attributed to the multifunctional laser-induced graphene, as either triboelectric materials, electrodes, or thermoacoustic sources. By systematically optimizing the structure parameters, the GHRI achieves high sensitivity (4500 mV Pa -1 ) and operating durability (1 000 000 cycles and 60 days), capable of recognizing speech identities, emotions, content, and other information in the human speech. With the assistance of machine learning, 30 speech categories are trained by a convolutional neural network, and the accuracy reaches 99.66% and 96.63% in training datasets and test datasets. Furthermore, GHRI is used for artificial intelligence communication based on recognized speech features. Our work shows broad prospects for the development of robotic intelligence.

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Carbonization of epoxy resin under high voltage discharge or exposure to high temperatures results in insulation failure. Herein, multiscale spherical boron nitride (SBN) epoxy resin is developed with improved anticarbonization properties. The thermal conductivity, thermostability, dielectric performances, volume resistivity, breakdown strength, and flame retardancy of the epoxy-SBN composites were studied. The thermal conductivity, thermostability, volume resistivity, and breakdown strength of epoxy-SBN composites are higher than that of pure resin, with a ratio of high thermal conductivity of 24 and a volume resistivity of ∼10. The AC breakdown voltage of the epoxy-30SBN composites was as high as 29.96 kV/mm. In addition, epoxy-30SBN composites possess minimal carbonization surface area under high-voltage discharge. Increased thermal conductivity, lower mass loss rate, high flame resistance, and inhibited charge carrier migration contribute to the improved carbonization resistance of the arc. Densified SBN networks in epoxy resin act as a dense barrier to achieve anticarbonization under high voltage stress or high-temperature exposure. Therefore, epoxy-SBN composites are promising candidates for application in next-generation high-voltage devices to ensure electrical safety.

Improving the output energy and durability remains a considerable challenge for the practical applications of triboelectric nanogenerator (TENGs). Owing to the interface effect of triboelectrification and electrostatic induction, thinner films with higher dielectric constants yield a higher output; however, they are not durable for practical applications. Herein, we change the dielectric surface effect into a volume effect by adopting a millimeter‐thick dielectric film with an inner porous network structure so that charges can hop in the surface state of the network. Charge migration inside the dielectric film is the key factor affecting the output of TENGs with a thick film, based on which each working stage follows the energy‐maximization principle in the voltage‐charge plot. The maximum peak and average power densities of TENGs with polyurethane foam film in 1 mm thickness reached 40.9 and 20.7 W m−2 Hz−1, respectively, under environmental conditions, and the output charge density was 5.14 times that of TENGs with a polytetrafluoroethylene film of the same thickness. Super durability was achieved in the rotary‐mode TENG after 200,000 operation cycles. This study identified the physical mechanism of the thick dielectric film used in TENGs and provided a new approach to promote the output and durability of TENGs.This article is protected by copyright. All rights reserved

Two-dimensional (2D) materials composed of pentagon and Janus motifs usually exhibit unique mechanical and electronic properties. In this work, a class of ternary carbonbased 2D materials, C m X n Y 6−m−n (m = 2, 3; n = 1, 2; X, Y = B, N, Al, Si, P), are systematically studied by first-principles calculations. Six of 21 Janus penta-C m X n Y 6−m−n monolayers are dynamically and thermally stable. The Janus penta-C 2 B 2 Al 2 and Janus penta-Si 2 C 2 N 2 exhibit auxeticity. More strikingly, Janus penta-Si 2 C 2 N 2 exhibits an omnidirectional negative Poisson ratio (NPR) with values ranging from −0.13 to −0.15; in other words, it is auxetic under stretch in any direction. The calculations of piezoelectricity reveal that the out-of-plane piezoelectric strain coefficient (d 32 ) of Janus panta-C 2 B 2 Al 2 is up to 0.63 pm/V and increases to 1 pm/V after a strain engineering. These omnidirectional NPR, giant piezoelectric coefficients endow the Janus pentagonal ternary carbonbased monolayers as potential candidates in the future nanoelectronics, especially in the electromechanical devices.

As a clean, sustainable energy source, sound can carry a wealth of information and play a huge role in the Internet of Things era. In recent years, triboelectric acoustic sensors have received increasing attention due to the advantages of self-power supply and high sensitivity. However, the triboelectric charge is susceptible to ambient humidity, which reduces the reliability of the sensor and limits the application scenarios significantly. In this paper, a highly moisture-resistant fluorinated polyimide composited with an amorphous fluoropolymer film was prepared. The charge injection performance, triboelectric performance, and moisture resistance of the composite film were investigated. In addition, we developed a self-powered, highly sensitive, and moisture-resistant porous-structure acoustic sensor based on contact electrification. The detection characteristics of the acoustic sensor are also obtained.

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In a transformer, the insulation materials will produce different dissolved gases due to various faults in the operation of the transformer, in which C2H2, CH4, and H2 are the main dissolved gases. In this study, the adsorption characteristics of the above three gases on the SnO2–GeSe monolayer surface were discussed and analyzed based on the density functional theory. The adsorption energy, transfer charge, geometric structure parameters, electronic density of states, electronic local function, charge difference density, and recovery time were calculated and compared to characterize the gas-sensing adsorption mechanism. The results showed that the SnO2–GeSe monolayer exhibited good adsorption capacity, selectivity, and repeatability for the three characteristic dissolved gases. After adsorbing CH4 gas molecules, the conductivity of the SnO2–GeSe monolayer decreased. After adsorbing C2H2 and H2 gas molecules, the conductivity of the SnO2–GeSe monolayer increased. Therefore, the SnO2–GeSe monolayer has great application potential in the real-time monitoring of dissolved gases in insulating materials, which may become a new type of resistive gas sensor.