Accumulated ice has brought much damage to engineering and people’s lives. The accumulation of ice can affect the flight safety of aircraft and lead to the failure of cables and power generation blades; it can even cause damage to human life. Traditional anti-icing and de-icing strategies have many disadvantages such as high energy consumption, low efficiency, or pollution of the environment. Therefore, inspired by animal communities, researchers have developed new passive anti-icing materials such as superhydrophobic material. In this paper, the solid surface wetting phenomenon and superhydrophobic anti-icing and de-icing mechanism were introduced. The methods of fabrication of superhydrophobic surfaces were summarized. The research progress of wear-resistant superhydrophobic coatings, self-healing/self-repairing superhydrophobic coatings, photothermal superhydrophobic coatings, and electrothermal superhydrophobic coatings in the field of anti-icing and de-icing was reviewed. The current problems and challenges were analyzed, and the development trend of superhydrophobic materials was also prospected in the field of anti-icing and de-icing. The practicality of current superhydrophobic materials should continue to be explored in depth.
Due to huge demand in engineering, vibration control technology and related studies have always been at the frontiers of research. Although traditional vibration control methods are stable and reliable, they have obvious shortcomings. Through evolution and natural selection, certain body-parts of animals in the natural world have been cleverly constructed and well designed. This provides a steady stream of inspiration for the design of vibration control equipment. The prime objective of this review is to highlight recent advances in the bionic design of vibration control devices. Current bionic vibration control devices were classified, and their bionic principles were briefly described. One kind was the bionic device based on the brain structure of the woodpecker, which is mostly used to reduce vibration at high frequencies. Another kind of bionic device was based on animal leg structure and showed outstanding performance in low frequency vibration reduction. Finally, we briefly listed the problems that need to be solved in current bionic vibration control technology and gave recommendations for future research direction.
In nature, aquatic organisms have evolved various attachment systems, and their attachment ability has become a specific and mysterious survival skill for them. Therefore, it is significant to study and use their unique attachment surfaces and outstanding attachment characteristics for reference and develop new attachment equipment with excellent performance. Based on this, in this review, the unique non-smooth surface morphologies of their suction cups are classified and the key roles of these special surface morphologies in the attachment process are introduced in detail. The recent research on the attachment capacity of aquatic suction cups and other related attachment studies are described. Emphatically, the research progress of advanced bionic attachment equipment and technology in recent years, including attachment robots, flexible grasping manipulators, suction cup accessories, micro-suction cup patches, etc., is summarized. Finally, the existing problems and challenges in the field of biomimetic attachment are analyzed, and the focus and direction of biomimetic attachment research in the future are pointed out.
The present study investigates the adsorption performance and adsorption mechanism of Sinogastromyzon szechuanensis on different rough surfaces. The different positions of the sucker surface of Sinogastromyzonszechuanensis were observed by adopting the stereomicroscope and SEM. The observed results showed that the sucker of Sinogastromyzonszechuanensis had a multilevel structure of villi and groove. The anterior and posterior of Sinogastromyzonszechuanensis had different microscopic morphologies. The surface roughness of the adsorption substrate ranged from 7 μm to 188 μm. Adsorption strength of Sinogastromyzonszechuanensis and the conventional sucker on different rough surfaces were measured by a purposely designed device. The results showed that the back of Sinogastromyzonszechuanensis mainly provided the adsorption strength. The adsorption strength of the conventional sucker gradually decreased with surface roughness increasing, but the adsorption strength of Sinogastromyzonszechuanensis had not changed significantly. Based on the experimental results, the adsorption mechanism of Sinogastromyzonszechuanensis on the surface with different roughness was analyzed by the spectral function. The Sinogastromyzonszechuanensis sucker with a multilevel structure worked well on the rough surface, which led to Sinogastromyzonszechuanensis with a good sealing on the rough surface. The present work could help to develop a new type of sucker with effective adsorption performance on a rough surface to meet the needs of the engineering field.
9 December 2022 in International Journal of Thermal Sciences
During the present study, a double groove texture was designed on the surface of a piston ring to improve the sealing performance between the piston ring and cylinder liner. The experimental design method was used to fabricate the test plan according to the groove width, depth, and spacing. By using the thermal–structural coupling analysis method, the finite element analysis of the standard piston ring and the textured piston ring was carried out to simulate the deformation state of the cylinder liner system of the piston ring group during the working stroke. The piston rings with different parameters designed by the test scheme were manufactured by wire electrical discharge machining, and the self-made experiment device carried out the sealing test. The results showed that the groove texture could improve the sealing performance of the piston ring, and the analyzed results demonstrated that the groove texture had little effect on the maximum deformation of the piston ring. Still, it could significantly reduce the minimum deformation of the piston ring group. A piston ring with groove texture would improve the sealing performance and reduce the deformation during the work stroke. During the test, the average deformation of the No.7 piston ring group, with a groove depth of 1 mm, a groove width of 0.5 mm, and a groove spacing of 0.1 mm, was the smallest, about 29.6% lower than that of the standard piston ring group. The sealing performance of the No.7 piston ring group was the best, and the reduction rate of the top gas leakage rate was 52.18%. During the present study, the sealing performance of the piston ring was improved by designing the grooved structure on the piston ring surface, thereby improving the fuel economy and power performance of the engine. The present study could provide a reference for the engineering field to design a piston ring with high sealing performance.