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Multifunctional flexible electronics have been a hot spot in scientific research and technology development. From the view of practical application, high-performance flexible heating devices with the capability to respond to commands are an urgent need for thermal management. Herein, we propose a strategy for multifunctional integration by assembling two pieces of laser-scribed Nomex paper, thus enabling the combination of heating and sensing modules. On account of the good electrothermal and piezoresistive properties of laser-induced graphene, the device can generate high steady-state temperature with a low voltage excitation and recognize valid commands from users finger to switch between operating states. Besides, the fast and efficient fabrication method entirely based on direct laser writing technology is another unique advantage. [ABSTRACT FROM AUTHOR]

Visual optical information encryption–decryption and anti‐counterfeiting (IEDAC) technology play a vital role in the field of information security. Recent luminescent information encryption technologies face the disadvantages of depending on external large‐scale stimulus decryption equipment, inability to read out repeatedly, and information leakage, impeding the practical applications of luminescence encryption. Here, an integrated luminescent IEDAC chip is proposed, which provides a convenient approach to store and decipher pre‐patterned luminescence information based on laser engraved template and film heater. The luminescent encryption chip contains a double‐layer structure made up of long persistent phosphors based on SrCaGa4O8 host and a laser induced graphene heater, which makes it possible to decrypt information on a single chip. This design enables dual‐mode (photoluminescence/long persistent luminescence), dual‐color (blue/yellow‐green), and multi‐level IEDAC function, providing a novel insight and integrated strategy for implementing advanced IEDAC technologies. [ABSTRACT FROM AUTHOR]

Based on micro-nano sensing technology, the structural and electronic characteristics of metal-doped boron nitride monolayer are investigated by first principles. The existing nano sensors have practical problems, such as no selectivity, too strong adsorption capacity to be recycled, too weak adsorption capacity to obtain sufficient response. We explore the use of a highly sensitive recyclable nano sensor that is best suited for sensing function. Gas adsorption properties for the toxic decomposition gases of C4F7 N are further developed. We select the N-vacancy with the highest binding energies, which are −6.34 eV when doped by Co atom. The strong interaction and suitable adsorption energy between the activated atoms of adsorbent and gases prove their unique adsorption properties. Since no new chemical bonds are formed, it is obvious that systems are in the form of physical adsorption, which proves their ideal desorption properties. In addition, the conductivity increases to different degrees due to the redistribution of electrons, which proves excellent selectivity. Hence, we propose the use of Co-BNN nanomaterial for the detection of C4F7N toxic decomposition gases. Results would serve as instructive reference for the investigation of resistive gas-sensitive sensors. [ABSTRACT FROM AUTHOR]

Real-time monitoring of SF6 status is of exceptional importance to ensure stable operation of the power system, to promptly diagnose whether an insulation failure has occurred and to assess the severity. Considering the excellent physicochemical properties and insulation defects of hexagonal boron nitride, the strategy of surface modification, namely, hydrogenation, fluorination, and combinations of the two ways, is proposed to improve its chemical activity, and the gas-sensing potential of the most effective one is investigated using density functional theory. The typical adsorption models of SF6 decomposition component gases on the surface of F-BN-H are constructed, and the most stable adsorption structures with their density of states, molecular orbitals, and sensing responses are analyzed. The results show that F-BN-H has good sensitivity to decomposition components of SF6. To be specific, SO2 and SOF2 have good adsorption properties, prominent charge transfer, and distinct change in electronic properties. The response of gas adsorption can be detected timely by the change in conductivity, and, additionally, the adsorbent has fast desorption capacity at room temperature. These results indicate that the F-BN-H-based gas sensor is a qualified potential candidate with dependable application and recoverability for detecting SF6 decomposition in high-voltage insulated equipment. [ABSTRACT FROM AUTHOR]

Motivated by the inevitable trend of the Internet of Everything, human-machine interaction technology has gradually been permeated into people's daily life. Receptive devices that capture human behaviors and responsive devices that provide machine feedback are key components of human-machine interface. While it is a great challenge to integrate receptive and responsive devices in a well-organized way due to the limitations of material properties and device structures. In this work, we investigate the formation of laser-induced graphene on Nomex paper and propose an efficient interactive strategy based on its piezoresistive and thermoacoustic effects. Functional integration of receiving instructions (pressure-sensing capability) and providing feedback (sound-emitting capability) can be achieved by simply assembling three layers of Nomex paper that have been laser-customized on both sides. The integrated device not only has a sensitive response (∼12 relative current change and ∼50 ms response time) to the pressure similar to a gentle finger press (∼10 kPa), but also can emit a high-quality sound signal with larger sound pressure levels (∼70 dB at 1 W/cm2 power density). Furthermore, two proof-of-concept demonstrations, a press-to-audio pad and a command-responding thermo-earphone, are presented to substantiate the feasibility in information exchange activities. [Display omitted] • Laser-induced graphene layers with favorable electrical conductivity are formed on Nomex paper. • Different conductive properties between double-sided laser-induced graphene across Nomex substrate are obtained by regulating laser power. • Pressure-sensing and sound-emitting capabilities are realized taking advantage of piezoresistive and thermoacoustic effects of laser-induced graphene. • Multifunctional integration is implemented by assembling three-layer Nomex paper that feature double-sided laser-induced graphene. [ABSTRACT FROM AUTHOR]

Laser engraving is carried out on the both sides of PI film to achieve constant temperature gas monitor and early automatic self-alarm. [Display omitted] • The LIG IDEs serve gas sensor, and rectangular LIG is usable in dual-working mode. • The rectangular LIG provides a constant working temperature under a DC voltage. • The NO 2 monitor with heating condition overcomes the inability to desorb at RT. • Let the device emit an acoustic alarm once NO 2 concentration is beyond threshold. The increasingly serious air pollution problem makes the development of high-performance gas monitoring system extremely urgent. Especially for nitrogen dioxide (NO 2), which is harmful to both people and the environment. The combination of reliable real-time monitoring and early warning is of great significance yet less study. Here, we designed a laser-induced graphene (LIG)-based multi-functional NO 2 monitor and self-alarm (MMSA), in which a rectangle area is used as a dual-functional module to realize high-performance temperature condition and acoustic alarm by applying direct/alternating current voltage excitation source. The molybdenum disulfide (MoS 2) sensitive material works in concert with the LIG interdigital electrodes (IDEs), and the gas monitor achieves high sensitivity (86.81% for 5 ppm, and 22.90% for 250 ppb) and excellent recoverability, aided by the good electrothermal property of LIG, overcoming the dilemma of poor sensing performance of MoS 2 at room temperature (RT). To top it off, the thermoacoustic effect of the LIG could bring about an intuitional sound signal, and a proof-of-concept demonstrates the timely acoustic warning response of the MMSA to exceeded NO 2 concentrations. [ABSTRACT FROM AUTHOR]