Since black silicon was discovered by coincidence, the special material was explored for many amazing material characteristics in optical, surface topography, and so on. Because of the material property, black silicon is applied in many spheres of a photodetector, photovoltaic cell, photo-electrocatalysis, antibacterial surfaces, and sensors. With the development of fabrication technology, black silicon has expanded in more and more applications and has become a research hotspot. Herein, this review systematically summarizes the fabricating method of black silicon, including nanosecond or femtosecond laser irradiation, metal-assisted chemical etching (MACE), reactive ion etching (RIE), wet chemical etching, electrochemical method, and plasma immersion ion implantation (PIII) methods. In addition, this review focuses on the progress in multiple black silicon applications in the past 10 years. Finally, the prospect of black silicon fabricating and various applications are outlined.

The rapid development of flexible sensor technology has made flexible sensor arrays a key research area in various applications due to their exceptional flexibility, wearability, and large-area-sensing capabilities. These arrays can precisely monitor physical parameters like pressure and strain in complex environments, making them highly beneficial for sectors such as smart wearables, robotic tactile sensing, health monitoring, and flexible electronics. This paper reviews the fabrication processes, operational principles, and common materials used in flexible sensors, explores the application of different materials, and outlines two conventional preparation methods. It also presents real-world examples of large-area pressure and strain sensor arrays. Fabrication techniques include 3D printing, screen printing, laser etching, magnetron sputtering, and molding, each influencing sensor performance in different ways. Flexible sensors typically operate based on resistive and capacitive mechanisms, with their structural designs (e.g., sandwich and fork-finger) affecting integration, recovery, and processing complexity. The careful selection of materials—especially substrates, electrodes, and sensing materials—is crucial for sensor efficacy. Despite significant progress in design and application, challenges remain, particularly in mass production, wireless integration, real-time data processing, and long-term stability. To improve mass production feasibility, optimizing fabrication processes, reducing material costs, and incorporating automated production lines are essential for scalability and defect reduction. For wireless integration, enhancing energy efficiency through low-power communication protocols and addressing signal interference and stability are critical for seamless operation. Real-time data processing requires innovative solutions such as edge computing and machine learning algorithms, ensuring low-latency, high-accuracy data interpretation while preserving the flexibility of sensor arrays. Finally, ensuring long-term stability and environmental adaptability demands new materials and protective coatings to withstand harsh conditions. Ongoing research and development are crucial to overcoming these challenges, ensuring that flexible sensor arrays meet the needs of diverse applications while remaining cost-effective and reliable.

For the development of supercapacitors, electrode materials with the advantages of simple synthesis and high specific capacitance are one of the very important factors. Herein, we synthesized g‐C₃N₄ and NiCo₂O₄ by thermal polymerization method and hydrothermal method, respectively, and finally synthesized NiCo₂O₄/g‐C₃N₄ nanomaterials by mixing, grinding, and calcining g‐C₃N₄ and NiCo₂O₄. NiCo₂O₄/g‐C₃N₄ nanomaterials are characterized by X‐ray diffraction and X‐ray photoelectron spectroscopy. The microscopic morphology, lattice structure, and element distribution of NiCo₂O₄/g‐C₃N₄ nanomaterials were characterized by scanning electron microscopy (SEM), transmission electron microscopy, high resoultion transmission electron microscopy, and mapping methods. The electrochemical performance and cycle stability of NiCo₂O₄/g‐C₃N₄ were tested in a 6 M KOH aqueous solution as electrolyte under a three‐electrode system. Due to the physical mixing structure of g‐C₃N₄ and NiCo₂O₄ nanomaterials, the electrochemical energy storage performance of NiCo₂O₄/g‐C₃N₄ supercapacitor electrodes is better than that of NiCo₂O₄ supercapacitor electrodes. At a current density of 1 A/g, the capacitances of NiCo₂O₄ and NiCo₂O₄/g‐C₃N₄ are 98.86 and 1,127.71 F/g, respectively. At a current density of 10 A/g, the capacitance of NiCo₂O₄/g‐C₃N₄ supercapacitor electrode maintains 70.5% after 3,000 cycles. NiCo₂O₄/g‐C₃N₄ electrode has excellent electrochemical performance, which may be due to the formation of physical mixing between NiCo₂O₄ and g‐C₃N₄, which has broad application prospects. This research is of great importance for the development of materials in high‐performance energy storage devices, catalysis, sensors, and other applications.

A piezoelectric micromachined ultrasonic transducer (PMUT) is a microelectromechanical system (MEMS) device that can transmit and receive ultrasonic waves. Given its advantages of high-frequency ultrasound with good directionality and high resolution, PMUT can be used in application scenarios with low power supply, such as fingerprint recognition, nondestructive testing, and medical diagnosis. Here, a PMUT based on an aluminum nitride thin-film material is designed and fabricated. First, the eigenfrequencies of the PMUT are studied with multiphysics coupling simulation software, and the relationship between eigenfrequencies and vibration layer parameters is determined. The transmission performance of the PMUT is obtained via simulation. The PMUT device is fabricated in accordance with the designed simple MEMS processing process. The topography of the PMUT vibration layer is determined via scanning electron microscopy, and the resonant frequency of the PMUT device is 7.43 MHz. The electromechanical coupling coefficient is 2.21% via an LCR tester.

The mesoporous CoTiO ₃ nanoparticles, which have been successfully prepared by a fast, simple and low‐cost hydrothermal method, show good decolourisation and degradation of methylene blue (MB). The synthesised samples can be recovered easily from solution by a magnetic mass. Surface morphology, structure, composition, and optical characteristics of the prepared CoTiO ₃ were determined using scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and ultraviolet–visible absorption measurements. The degradation percentage of MB was nearly 95% at an initial concentration of 10 ppm in 90 min. Such enhanced photocatalytic activities of synthesised CoTiO ₃ were attributed to a large specific surface area (54.22 m ² g ⁻¹ ) and defects density, which was useful for restraining surface recombination of photo‐generated charge carriers. The recovery of CoTiO ₃ nanoparticles was about 85% and the degradation rate of MB remained 80% after five cycles. As a whole, the CoTiO ₃ nanocomposites give a synergistic effect in photocatalytic and magnetic behaviour and indicate that the synthesised samples have a promising potential particularly for water purification and environmental remediation.