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Flexible perovskite solar cells (FPSCs) with high stability in moist air are required for their practical applications. However, the poor mechanical stability under high humidity air remains a critical challenge for flexible perovskite devices. Herein, inspired by the exceptional wet adhesion of mussels via dopamine groups, we propose a multidentate-cross-linking strategy, which combine multibranched structure and adequate dopamine anchor sites in three-dimensional hyperbranched polymer to directly chelate perovskite materials in multiple directions, therefore construct a vertical scaffold across the bulk of perovskite films from the bottom to the top interfaces, intimately bind to the perovskite grains and substrates with a strong adhesion ability, and enhance mechanical durability under high humidity. Consequently, the modified rigid PSCs achieve superior PCE up to 25.92%, while flexible PSCs exhibit a PCE of 24.43% and maintain 94.1% of initial PCE after 10,000 bending cycles with a bending radius of 3 mm under exposed to 65% humidity. Poor mechanical stability under high humidity remains a critical challenge for flexible perovskite solar cells. Here, the authors develop a bioinspired dopamine containing polymer to enhance adhesion in humid environments, achieving an efficiency of nearly 26%.

With the development of wearable devices and hafnium-based ferroelectrics (FE), there is an increasing demand for high-performance flexible ferroelectric memories. However, developing ferroelectric memories that simultaneously exhibit good flexibility and significant performance has proven challenging. Here, we developed a high-performance flexible field-effect transistor (FeFET) device with a thermal budget of less than 400 °C by integrating Zr-doped HfO 2 (HZO) and ultra-thin indium tin oxide (ITO). The proposed FeFET has a large memory window (MW) of 2.78 V, a high current on/off ratio (I ON /I OFF ) of over 10 8 , and high endurance up to 2×10 7 cycles. In addition, the FeFETs under different bending conditions exhibit excellent neuromorphic properties. The device exhibits excellent bending reliability over 5×10 5 pulse cycles at a bending radius of 5 mm. The efficient integration of hafnium-based ferroelectric materials with promising ultrathin channel materials (ITO) offers unique opportunities to enable high-performance back-end-of-line (BEOL) compatible wearable FeFETs for edge intelligence applications. Using Zr-doped HfO2 and ultra-thin indium tin oxide, Li et al. develop flexible field-effect transistors with a memory window of 2.78 V and bending reliability to enable high-performance back-end-of-line compatible wearable devices.

A calculation formula for the neutral layer offset under different deflection conditions is derived based on elastoplastic mechanics theory to enhance the straightening accuracy of bimetallic composite pipes during the straightening process. Using the Abaqus simulation software, various deflection levels of the bimetallic composite pipes are achieved by applying different downward displacements. The strain variation curve of the neutral layer is extracted, and the relationship between the neutral layer offset and the bending radius is analyzed. The accuracy of the derived formula is validated by comparing the theoretical formula with the simulation results of the neutral layer offset curve.

The Boltzmann distribution of electrons sets a fundamental barrier to lowering energy consumption in metal-oxide-semiconductor field-effect transistors (MOSFETs). Negative capacitance FET (NC-FET), as an emerging FET architecture, is promising to overcome this thermionic limit and build ultra-low-power consuming electronics. Here, we demonstrate steep-slope NC-FETs based on two-dimensional molybdenum disulfide and CuInP 2 S 6 (CIPS) van der Waals (vdW) heterostructure. The vdW NC-FET provides an average subthreshold swing (SS) less than the Boltzmann’s limit for over seven decades of drain current, with a minimum SS of 28 mV dec −1 . Negligible hysteresis is achieved in NC-FETs with the thickness of CIPS less than 20 nm. A voltage gain of 24 is measured for vdW NC-FET logic inverter. Flexible vdW NC-FET is further demonstrated with sub-60 mV dec −1 switching characteristics under the bending radius down to 3.8 mm. These results demonstrate the great potential of vdW NC-FET for ultra-low-power and flexible applications. The adaptation to atomically thin 2D semiconductors and van der Waals layered ferroelectrics can enable negative capacitance transistors with superior performance and bendability. Here, the authors report flexible negative capacitance transistors based on MoS2 and a ferroelectric dielectric CIPS with a minimum sub-threshold slope of 28 mV/dec and high gain logic invertors.

The thermal pipeline is important to play an important role in the operation of thermal power plant equipment, and the safe and stable operation of the body and accessories is very important. The elbow, as an indispensable part of the thermal pipeline, directly affects the safety of the unit. On the basis of the GB/T 16507-2013 “Water Pipe Boiler” standard, this article uses the simulation simulation software to analyze the stress of 90 ° elbow under different bending radius. Distribution status. The calculation results show that: under the same wall thickness, the maximum stress is concentrated in the inner arc. As the curved radius R increases, the maximum stress of the inner arc gradually decreases. At the same time Instead, it gradually increased. Under different wall thickness, the maximum stress occurs at the outer arc.

The bending behavior of the hydraulic pipeline on the roller of the logging winch will cause a certain plastic deformation of the hydraulic pipeline, which has a certain influence on its performance. In view of the above problems, this paper uses finite element analysis software to analyze the plastic deformation law of hydraulic pipelines under different bending radii. It can be found from the analysis results that during the bending process, the plastic deformation of the metal continuous capillary gradually increases with the neutral layer outward. In the range of the bending radius from 75 mm to 150 mm, with the increase of the bending radius, the equivalent plastic deformation decreases from 3.5×10 -2 to 1.46×10 -2 . The changing trend of life also tends to be gentle with the increase of the bending radius, and the number of cycles increases from 25000 to 398107. The analysis of the plastic deformation law and the life of hydraulic pipelines provides a reference for designing winch drums.

In recent years, the electrification of automobiles and the studies to electrify also aircraft have accelerated as a measure against global warming, necessitating improvements in motor efficiency and power density to reduce CO2 emissions. The possibility to increase the motor’s rotation speed is, a key factor in enhancing power density. However, high-speed rotation means that higher operative frequency are used thus increasing eddy currents and iron loss. To mitigate these effects, thin ribbons, powders, and thin magnetically soft wires are effective stator materials. Yet, the magnetic properties of these materials deteriorate when bent to form motor components, making it essential to consider the impact of bending stress on magnetic properties during the motor design stage. This study investigates the effect of bending stress on the magnetic properties of thin wire magnetic materials (electrical steel) using the coaxial H coil method. The magnetic properties and iron loss curves for various bending radii R were determined using this method. The findings of this study will influence the design of motors using thin wire magnetic materials.

Many sheet metal parts go through a bending operation during the manufacturing process. Compared to deep-drawing operations, failure in bending operations cannot be predicted accurately with a forming limit curve from the Nakajima or Marciniak experiment, especially in a pre-deformed state. Due to the small bending radii and the associated strong curvature, the failure only occurs with significantly higher strains for states without pre-deformation. Likewise, the failure is not caused by a localization, but by damage to the outer surface of the sample. The introduction of pre-deformation in the sheet material leads to development of texture and damage, where these mechanisms depend on the loading direction. If such pre-deformed sheet material is subsequently bent, the sample may fail unexpectedly early compared to the initial forming limit curve. The present experimental work aims at investigating the influence of pre-deformation and subsequent loading direction for different materials. Therefore, specimens have been pre-deformed in different orientations, followed by bending tests in different orientations. Different pre-deformation levels and loading directions combinations on three sheet materials were investigated. Based on the experimental results a so called bending forming limit curve (BFLC) can be derived enabling enhanced prediction of failure for bending processes after pre-deformation.

Electrolyte-gated transistors (EGTs) hold great promise for next-generation printed logic circuitry, biocompatible integrated sensors, and neuromorphic devices. However, EGT-based complementary circuits with high voltage gain and ultralow driving voltage (<0.5 V) are currently unrealized, because achieving balanced electrical output for both the p- and n-type EGT components has not been possible with current materials. Here we report high-performance EGT complementary circuits containing p-type organic electrochemical transistors (OECTs) fabricated with an ion-permeable organic semiconducting polymer (DPP-g2T) and an n-type electrical double-layer transistor (EDLT) fabricated with an ion-impermeable inorganic indium-gallium-zinc oxide (IGZO) semiconductor. Adjusting the IGZO composition enables tunable EDLT output which, for In:Ga:Zn = 10:1:1 at%, balances that of the DPP-g2T OECT. The resulting hybrid electrolyte-gated inverter (HCIN) achieves ultrahigh voltage gains (>110) under a supply voltage of only 0.7 V. Furthermore, NAND and NOR logic circuits on both rigid and flexible substrates are realized, enabling not only excellent logic response with driving voltages as low as 0.2 V but also impressive mechanical flexibility down to 1-mm bending radii. Finally, the HCIN was applied in electrooculographic (EOG) signal monitoring for recording eye movement, which is critical for the development of wearable medical sensors and also interfaces for human-computer interaction; the high voltage amplification of the present HCIN enables EOG signal amplification and monitoring in which a small ∼1.5 mV signal is amplified to ∼30 mV.

To extensively investigate the bi-directional bending behavior of sheet metal, double-curved bending experiments with radius ratios ranging from 1:1 to 6:1 were conducted based on TA3 titanium alloy square and rectangular sheets. In combination with finite element simulation, the evolution trend of the blank-die contact area and material flow rule were investigated. The results show that the radius combination and specimen shape both have a remarkable effect on the evolution of blank-die contact area and bending deformation mode. The evolution trend of the contact area is mainly dependent on the combination of the bending radius. Material flows from the centre to its surrounding area in a double curvature bending process. The greater the sheet bending radius ratio, the more apparent the flowing phenomenon is observed along the larger curvature direction. The finite element predicted results agree well with experimental results. The new findings in this paper not only expand the bending theoretical basis but also provide valuable reference for the double-curved parts.