Owing to the outstanding physical properties of graphene, its biosensing applications implemented by the terahertz metasurface are widely concerned and studied. Here, we present a novel design of the graphene metasurface, which consists of an individual graphene ring and an H-shaped graphene structure. The graphene metasurface exhibits a dual-resonance response, whose resonance frequency strongly varies with the geometrical parameters of the proposed metasurface, the carrier density of graphene, and the analyte composition. The transparency window, including width and position, can be artificially controlled by adjusting the geometrical parameters or the Fermi energy. Furthermore, the sensing parameters of the graphene metasurface for cancerous and normal cells are investigated, focusing on two factors, namely cell quantity and position on the metasurface. The simulated results clearly show that the theoretical sensitivity, figure of merit, and quantity of the graphene metasurface for breast cells reach 1.21 THz/RIU, 2.75 RIU${}^{-1}$, and 2.43, respectively. Our findings may open up new avenues for promising applications in the diagnosis of cancers.

Nitrogen dioxide (NO2) is a representative toxic gas that plays a key role in variety of fields. Due to its extensive application, the demands for reliable sensors to detect NO2 are extremely urgent. Here, we report the adsorption of N2, CO2, O2, and NO2 molecules on the GeS monolayer from atomic scale to device scale by first principles and molecular dynamics method. The results indicate that the GeS monolayer is sensitive to NO2 molecules with moderate adsorption energy and pronounced charge transfer. Remarkably, the sorption quantity of the GeS monolayer for NO2 is 708.707 mg/g under the 101.33 kPa, which is much higher than other molecules. Additionally, the I-V characteristic reveals that when the NO2 molecule is adsorbed, the resistance of the GeS monolayer is nontrivially and distinctly changed. The extraordinary sensitivity and selectivity of the GeS monolayer for NO2 molecules suggests the GeS monolayer is a potential sensing material for NO2 gas.

This study introduces a novel strategy for fabricating flexible nitrogen dioxide (NO ₂ ) gas sensors based on Indium Oxide (In ₂ O ₃ ) nanoparticles (NPs) employing selective reduction laser sintering (SRLS) technology. The SRSL technology utilizes ultraviolet (UV) laser selective reduction sintering to precisely and rapidly create oxygen vacancy (OV) defects in In ₂ O ₃ NPs. These oxygen vacancies (OVs) enhance the active adsorption sites and contribute additional free electrons, significantly improving sensor performance at room temperature. The sensors demonstrate excellent response ( S = 460.9 at 10 ppm), rapid response/recovery times ( τ _resp / τ _reco = 27/570 s), and superior selectivity (response ratio > 400), in addition to robust resistance to light and humidity (under ppm‐level NO ₂ gas). The sensors also exhibit a low detection limit (200 ppb), a high signal‐to‐noise ratio (94.8 dB), and good long‐term stability (25 days). Moreover, under photo‐assisted conditions, the recovery speed of the sensors is further improved. This technology not only provides an innovative strategy for the development of high‐performance flexible NO ₂ gas sensors but also broadens the application potential of laser direct writing (LDW) technology in advanced materials and sensor fabrications.

Using TCAD simulations, the silicon carbide metal-oxide-semiconductor field-effect transistor with p-type floating islands (SiC FLIMOSFET) is systematically investigated in this paper. The doping concentration (NFLI), length (L), and position (D1) of floating islands are optimized according to breakdown voltage (BV), electric field distribution, and on-resistance. The results show that NFLI = 1 x 10¹⁷ cm⁻³, L= 2.5 μm, and D1=9.0 μm are superior values for FLI structure considering tradeoff between BV and on-resistance. With the same BV capacity, the on-resistance of SiC FLIMOSFET is decrease by 32% comparing to the conventional SiC VDMOSFET. Besides, the dynamic property shows 16.5% reduction of FoM Ron· QGD in the SiC FLIMOSFET. Significantly, comparing to the conventional structure, the electro-thermal simulation indicates that the SiC FLIMOSFET has a higher robustness under short-circuit condition owing to the reduction of thermal stress in SiC/SiO₂ interface. All the results show that the SiC FLIMOSFET has a good potential in SiC power device.

Recent reports focus on the hydrogenation engineering of monolayer boron phosphide and simultaneously explore its promising applications in nanoelectronics. Coupling density functional theory and finite element method, we investigate the bowtie triangle ring microstructure composed of boron phosphide with hydrogenation based on structural and performance analysis. We determine the carrier mobility of hydrogenated boron phosphide, reveal the effect of structural and material parameters on resonance frequencies, and discuss the variation of the electric field at the two tips. The results suggest that the mobilities of electrons for hydrogenated BP monolayer in the armchair and zigzag directions are 0.51 and 94.4 cm²·V${}^{-1}$·s${}^{-1}$, whereas for holes, the values are 136.8 and 175.15 cm²·V${}^{-1}$·s${}^{-1}$. Meanwhile, the transmission spectra of the bowtie triangle ring microstructure can be controlled by adjusting the length of the bowtie triangle ring microstructure and carrier density of hydrogenated BP. With the increasing length, the transmission spectrum has a red-shift and the electric field at the tips of equilateral triangle rings is significantly weakened. Furthermore, the theoretical sensitivity of the BTR structure reaches 100 GHz/RIU, which is sufficient to determine healthy and COVID-19-infected individuals. Our findings may open up new avenues for promising applications in the rapid diagnosis of COVID-19.

In recent years, metal crack-based stretchable flexible strain sensors have attracted significant attention in wearable device applications due to their extremely high sensitivity. However, the trade-off between sensitivity and detection range has been an intractable dilemma, severely limiting their practical applications. Herein, we propose a laser transmission pyrolysis technology for fabricating high-performance flexible strain sensors based on (Au) metal cracks with the microchannel array on the polydimethylsiloxane (PDMS) surface. The fabricated flexible strain sensors exhibit high sensitivity (gauge factor of 2448), wide detection range (59% for tensile strain), precise strain resolution (0.1%), fast response and recovery times (69 ms and 141 ms), and robust durability (over 3000 cycles). In addition, experiment and simulation results reveal that introducing a microchannel array enables the stress redistribution strategy on the sensor surface, which significantly improves the sensing sensitivity compared to conventional flat surface sensors. Based on the excellent performance, the sensors are applied to detect subtle physiological signals such as pulse and swallowing, as well as to monitor large-scale motion signals such as knee flexion and finger bending, demonstrating their potential applications in health monitoring, human-machine interactions, and electronic skin.