Honeycomb sandwich structures (HSSs) are excellent candidates for light and efficient microwave-absorbing materials. In this work, we design an HSS using SiO₂ fiber-reinforced epoxy resin (SiO_2f/ER) composites as both the top and bottom layers to improve the impedance matching with free space. Target dielectric properties of the honeycomb and coated lossy material of the HSS were calculated based on the multilayer transmission line theory, metal backplane model, and homogenization theory. In addition, the interface effect between the SiO_2f/ER and honeycomb of the HSS was discussed theoretically, experimentally, and numerically, indicating a 1–4% contribution of microwave absorption resulting from the interface. By analyzing the equivalent resistance, equivalent capacitance, as well as equivalent inductance, the enhanced microwave absorption of HSS is attributed to the formation of the interfacial transition zone, which benefits both impedance matching and electromagnetic loss.

The development of broadband and high-efficiency broadband microwave-absorbing materials is one of the keys to resisting electromagnetic radiation and electromagnetic interference. In this paper, we used zeolitic imidazolate framework-67 (ZIF-67) as the template to obtain Ni-doped ZIF-67 via Ni(NO₃)₂ etching followed by pyrolysis to prepare Co-Ni/C composites successfully. The morphology and microstructure of Co-Ni/C composites can be well-tuned by altering the Ni doping content. ZIF-67-derived Co-Ni/C porous materials exhibit extremely strong microwave absorption performance thanks to dielectric loss, magnetic loss, and the synergistic effect between different components. When the dosage of Ni(NO₃)₂ used reaches 0.32 g, the obtained composite possesses the optimal absorbing properties with a maximum reflection loss (RL) of −72.88 dB and an effective bandwidth (f_e, representing RL ≤ −10 dB) of 7.04 GHz (9.76–16.8 GHz) corresponding to a thickness of 2.53 mm. The results of this work indicate that Co-Ni/C composites have potential application value in the field of microwave absorption.

Fiber-reinforced resin matrix composites have been widely used in aerospace, construction, transportation and other industries due to their excellent mechanical properties and flexible structural design. However, due to the influence of the molding process, the composites are easily delaminated, which greatly reduces the structural stiffness of the components. This is a common problem in the processing of fiber-reinforced composite components. In this paper, through the combination of finite element simulation analysis and experimental research, drilling parameter analysis was carried out for prefabricated laminated composites, and the influence of different processing parameters on the processing axial force was qualitatively compared. The inhibition rule of variable parameter drilling on the damage propagation of initial laminated drilling was explored, which further improves the drilling connection quality of composite panels with laminated materials.

Ionogels have attracted tremendous interest for flexible electronics due to their excellent deformability, conductivity, and environmental stability. However, most ionogels suffer from low strength and poor toughness, which limit their practical applications. This article presents a strategy for fabricating ionogels with high toughness by constructing high-density hydrogen bonds within their microstructure. The ionogels exhibit a maximum fracture strength of 11.44 MPa, and can sustain a fracture strain of 506%. They also demonstrate a fracture energy of 27.29 MJ m⁻³ and offer a wide range of mechanical property adjustments (fracture stress from 0.3 to 11.44 MPa, fracture strain from 506% to 1050%). Strain sensors assembled with ionogels demonstrate exceptional sensing performance and enable motion detection of human joints. This study provides a new approach for achieving strong and tough ionogel design used for high-performance flexible electronic applications.