Flexible piezoelectric composite (FPC) materials with strong designability are increasingly utilized in vibration control and structural health monitoring. The sensing and actuating performances of FPCs are directly affected by the several parameters, such as ceramic fiber volume fraction, flexible interdigitated electrode width, electrode spacing, and component thicknesses. These parameters should be optimized in order to make the tradeoff between the sensing-actuation performance and the compliance. This study systematically explored the relationships between material properties (such as electrostrain coefficients, dielectric coupling coefficients, and compliance matrix) and component parameters. A representative volume element (RVE) model at the microscale was employed to investigate the electric field distribution and sensing/actuation effects of FPCs with varying parameter configurations under voltage excitation. This analysis identified optimal component parameter ratios for FPCs, providing a theoretical foundation for their design and fabrication. The study concluded that an FPC with a ceramic fiber volume fraction of 75%, electrode spacing of 0.1 mm, and electrode width of 0.01 mm achieves optimal sensing and actuation performance while maintaining good compliance. This research offers valuable insights for the development of flexible piezoelectric composites with tailored properties for advanced applications.

High-entropy ceramics (HECs) have attracted growing research attention since 2015, when the pioneering work on entropy-stabilized oxides was first reported. Derived from the definition of high-entropy alloys, HECs initially referred to disordered ceramic solid solutions comprising five or more principal elements in equimolar ratios occupying the same Wyckoff sites. The concept has rapidly evolved to encompass more complex systems with tunable element distributions across multiple crystallographic positions. Distinct from conventional ceramics, HECs are characterized by their unique chemical diversity and high configurational entropy, which contribute to enhanced structural stability and promising functional properties. Given the remarkable progress of HECs, this review systematically summarizes advancements over the past five years, including oxides (both simple and complex) and non-oxides (carbides, borides, and related compounds). Specifically, we focus on theoretical design principles for stability prediction and property optimization. We then examine the expanding compositional and structural space of emerging compounds and also discuss structure-property correlations and innovative processing methods. Furthermore, we provide a comprehensive overview of the most extensively investigated properties, including mechanical, thermal, electrical, catalytic, magnetic and dielectric characteristics. Looking forward, HECs hold great promise for various applications, and this review may provide some fundamental insights and practical design strategies for realizing their full potential.

As a new member of two-dimensional (2D) materials family, 2D transition metal borides (MBenes) have attracted rising attention owing to the remarkable thermodynamic stability, electrical and mechanical properties. Over the past several years, the study of MBenes has been extended from theoretical simulations to experimental applications, stimulated by the increasing synthesis methods of MBenes. However, the recent experimental applications about MBenes have not been comprehensively introduced. This review concentrates on a comprehensive overview of MBenes which have accordion-like structures derived from multilayer MAB phases and their relevant experimental progress. First, the concept of MBenes, development progress, structural, basic properties are introduced. Then synthetic routes for the production of MBens, including alkaline/acid solution, dealloying, molten salt-assisted etching methods are surveyed. Subsequently, the introduction and analysis of the latest applications such as metal-ion batteries, metal-air batteries, photocatalysis, electrochemical catalysis, sensors, environmental technology, magnetism, lubrication are summarized. Finally, perspectives and challenges for MBenes in synthesis and applications are briefly presented.

In order to get a comprehensive understanding of the corrosion behaviour of mild steel (110) with alanine, arginine, cysteine, and tyrosine in gas and aqueous phases, a systematic theoretical study using MC simulation was conducted in the current investigation. Stronger interfacial spontaneous adsorption of amino acid molecules across the Fe (110) surface in the investigated environment is made possible by the more negative adsorption energy values found in the MC simulation. Effectively repelling the corrosive particles from the substrate and delaying their aggregation are the capabilities of four amino acids. The results of the MC simulation also show that, in order to stop corrosion, amino acid molecules replace any other ions or solvent water that had previously been adsorbed on the metal surface. The trend of tyrosine > cysteine > alanine > arginine is shown by the protection capacity derived from the MC simulation. Furthermore, the DFT studies demonstrate that, charge transfer takes place within the molecule based on the calculated E-HOMO and E-LUMO energies. When adsorbed onto a metal surface, heteroatoms like nitrogen, oxygen, and sulphur in an amino acid structure provide the stronger inhibition. The decreased HOMO-LUMO gap, indicating improved electronic contact with the Fe (1 1 0) surface. A greater reactivity and potential for electron transfer are suggested by the EHOMO and ELUMO values (EHOMO −19.71 eV for alanine, −16.83 for cysteine, −10.73 for arginine and −16.80 for tyrosine) and (ELUMO EHOMO −10.81 eV for alanine, -−9.34 for cysteine, −2.69 for arginine and −9.06 for tyrosine) which are advantageous for adsorption onto the Fe (1 1 0) surface. Current study finds that, alanine, arginine, cysteine and tyrosine were emerging as a novel and effective and sustainable corrosion resistance agent for acid pickling and cleaning procedures. These outcomes may lead to the development of more and large-scale green inhibitors and a better understanding of their mechanisms for eco-friendly industrial processes.