Fiber Metal Laminates (FMLs), as high-performance composite materials, demonstrate exceptional potential in a wide range of applications, such as aeronautical and astronautical industries. However, the traditional cured FMLs possess complex interlayer stresses and low forming limits, restricting further promotion and application of FMLs. Low-constraint FMLs exhibit a lower forming resistance and better formability due to no curing during the forming process; however, the formation mechanism and response are not clear. This paper presents the Forming Limit Diagram (FLD) of low-constraint GLARE (glass fiber reinforced aluminum laminates) based on the forming limit test, and compares it with the conventionally cured laminates to evaluate the differences in the forming limit. In addition, combined with the analysis of failure mechanism and micro-deformation mechanism of specimens, the influence of different temperatures (20–80 ℃) and forming states (width) on the deformation performance of laminates is further explored. The results reveal that the forming limit curve of low-constraint laminates shifts up with the increase of temperature, the forming limit initially increases with the increase of width, then followed by a gradual decrease, and the maximum principal strain of low-constraint laminates is increased by 29% at 80 ℃ compared to 20 ℃. The cured laminate has a principal strain range of 0–0.02, while the low-constraint laminates have a principal strain range of 0.03–0.14. Compared with cured laminates, low-constraint laminates possess a higher forming limit due to the improvement in deformable degree between layers by resin flow and fiber slippage, which enhances their formability. This study is expected to serve as a reference for establishing forming limit criteria and optimizing forming schemes for low-constraint laminates.

Two-dimensional (2D) materials are potential candidates for electronic devices due to their unique structures and exceptional physical properties, making them a focal point in nanotechnology research. Accurate assessment of the mechanical and tribological properties of 2D materials is imperative to fully exploit their potential across diverse applications. However, their nanoscale thickness and planar nature pose significant challenges in testing and characterizing their mechanical properties. Among the in situ characterization techniques, atomic force microscopy (AFM) has gained widespread applications in exploring the mechanical behaviour of nanomaterials, because of the easy measurement capability of nano force and displacement from the AFM tips. Specifically, AFM-based force spectroscopy is a common approach for studying the mechanical and tribological properties of 2D materials. This review comprehensively details the methods based on normal force spectroscopy, which are utilized to test and characterize the elastic and fracture properties, adhesion, and fatigue of 2D materials. Additionally, the methods using lateral force spectroscopy can characterize the interfacial properties of 2D materials, including surface friction of 2D materials, shear behaviour of interlayers as well as nanoflake-substrate interfaces. The influence of various factors, such as testing methods, external environments, and the properties of test samples, on the measured mechanical properties is also addressed. In the end, the current challenges and issues in AFM-based measurements of mechanical and tribological properties of 2D materials are discussed, which identifies the trend in the combination of multiple methods concerning the future development of the in situ testing techniques.

Strain engineering, as a cutting-edge method for modulating the electronic structure of catalysts, plays a crucial role in regulating the interaction between the catalytic surface and the adsorbed molecules. The electrocatalytic performance is influenced by the electronic structure, which can be achieved by introducing the external forces or stresses to adjust interatomic spacing between surface atoms. The challenges in strain engineering research lie in accurately understanding the mechanical impact of strain on performance. This paper first introduces the basic strategy for generating the strain, summarizes the different strain generation forms and their advantages and disadvantages. The progress in researching the characterization means for the lattice strains and their applications in the field of electrocatalysis is also emphasized. Finally, the challenges of strain engineering are introduced, and an outlook on the future research directions is provided.

The ideal composite electrolyte for the pursued safe and high-energy-density lithium metal batteries (LMBs) is expected to demonstrate peculiarity of superior bulk conductivity, low interfacial resistances, and good compatibility against both Li-metal anode and high-voltage cathode. There is no composite electrolyte to synchronously meet all these requirements yet, and the battery performance is inhibited by the absence of effective electrolyte design. Here we report a unique “concentrated ionogel-in-ceramic” silanization composite electrolyte (SCE) and validate an electrolyte design strategy based on the coupling of high-content silane-conditioning garnet and concentrated ionogel that builds well-percolated Li⁺ transport pathways and tackles the interface issues to respond all the aforementioned requirements. It is revealed that the silane conditioning enables the uniform dispersion of garnet nanoparticles at high content (70 wt%) and forms mixed-lithiophobic-conductive LiF-Li₃N solid electrolyte interphase. Notably, the yielding SCE delivers an ultrahigh ionic conductivity of 1.76 × 10⁻³ S cm⁻¹ at 25 ℃, an extremely low Li-metal/electrolyte interfacial area-specific resistance of 13 Ω cm², and a distinctly excellent long-term 1200 cycling without any capacity decay in 4.3 V Li||LiNi_0.5Co_0.2Mn_0.3O₂ (NCM523) quasi-solid-state LMB. This composite electrolyte design strategy can be extended to other quasi−/solid-state LMBs.

The high sensitivity of room-temperature gas sensors is the key to innovation in the areas of environment, energy conservation and safety. However, metal-oxide-based sensors generally operate at high temperatures. Herein, we designed three ZrO₂-based sensors and explored their NO₂ sensing properties at room temperature. ZrO₂ with three different morphologies and microstructure were synthesized by simple hydrothermal methods. The microstructures of sensing materials are expected to significantly affect gas sensing properties. The rod-shaped ZrO₂ (ZrO₂-R) displayed the advantages such as higher crystallinity, larger pore size, narrower band gap and more chemisorbed adsorbed oxygen, compared to hollow sphere-shaped ZrO₂ (ZrO₂-HS), stellate-shaped ZrO₂ (ZrO₂–S). The ZrO₂-R sensor showed the highest response towards 30 ​ppm NO₂ (423.8%) at room temperature, and a quite high sensitivity of 198.0% for detecting 5 ​ppm NO₂. Although ZrO₂-HS and ZrO₂–S sensors exhibited lower response towards 30 ​ppm NO₂ (232.9% and 245.1%), the response time and recovery time of these two sensors are 5 ​s/19 ​s and 4 ​s/3 ​s, respectively. This work can provide a new strategy for the development of room-temperature metal-oxide-based sensors.