Parameters optimization for ferrite slicing based on grey theory

To optimize the parameters of slicing ferrite with high precision diamond ring saw, an orthogonal test is designed with the fabricating surface accuracy and the surface roughness as evaluation indicators and the spindle speed, the feed speed and the tension force as factors. Based on the grey theory, the data analysis and the comprehensive evaluation of the multiple process targets are carried out to obtain an optimized process parameter combination, namely the spindle speed 1 000 r/min, the feed speed 1.0 mm/min and the tension force 90 N. The slicing test results show that the optimized parameter combination can obtain a surface accuracy of PV 7.37 μm and a surface roughness Ra of 0.882 μm, and the slicing surface quality is improved, which verifies the effectiveness and practicability of this method in the optimization of ferrite slicing process parameters

Geometrical incompatibility guides pattern selection in growing bilayer tubes

Pattern selection and subsequent morphological evolution are of remarkable significance, since they are critical for living creatures to fulfill certain biological functions and also have widespread potential applications from disease diagnosis to advanced manufacturing. Geometrical incompatibility is omnipresent in biological systems and plays a critical role in pattern selection of the growing soft biological tissues. However, how geometrical incompatibility guides pattern selection in growing soft matter remains poorly understood. Here, we present a theoretical model to investigate the influence of geometrical incompatibility on pattern selection of growing bilayer tubes. Our linear stability analysis illustrates that an increase of the geometrical incompatibility parameter provokes the instability pattern transition from a longitudinal pattern to a two-dimensional (2D) pattern and then to a circumferential pattern. Based on the theoretical model, a series of quantificational experiments and finite element simulations are implemented to study how geometrical incompatibility guides pattern selection of growing bilayer tubes and explore the post-buckling evolution of the emerging patterns. Both the numerical simulations and experimental observations agree well with our theoretical predictions. In particular, with further growth far beyond the threshold, a secondary bifurcation is observed in the post-buckling evolution of the 2D pattern. This study suggests that geometrical incompatibility can serve as an implementable experimental tool to quantificationally guide pattern selection and subsequent morphological evolution of growing soft matter, which can be used for growth self-assembly and multifunctional surface manufacturing

Pio IX

Initial residual stress is omnipresent in biological tissues and soft matter, and can affect growth-induced pattern selection significantly. Here we demonstrate this effect experimentally by letting soft tubes grow in the presence or absence of initial residual stress and by observing different growth pattern evolutions. These experiments motivate us to model the mechanisms at play when a growing bilayer tubular organ spontaneously displays buckling patterns on its inner surface. We demonstrate that not only differential growth, geometry and elasticity, but also initial residual stress distribution, exert a notable influence on these pattern phenomena. Prescribing an initial residual stress distribution offers an alternative or a more effective way to implement pattern selection for growable bio-tissues or soft matter. The results also show promise for the design of 4D bio-mimic printing protocols or for controlling hydrogel actuators.We gratefully acknowledge support from National Natural Science Foundation of China (grants 11621062/11772295) and China Scholarship Council.2020-10-0

Soft Display Using Photonic Crystals on Dielectric Elastomers

Soft display has been intensively studied in recent years in the wake of rapid development of a variety of soft materials. The currently existing solutions for translating the traditional hard display into the more convenient soft display mainly include light-emitting diodes, liquid crystals, quantum dots, and phosphors. The desired soft display should take the advantages of facile fabrication processes and cheap raw materials. Besides, the device should be colorful, nontoxic, and not only flexible but also stretchable. However, the foregoing devices may not own all of the desired features. Here, a new type of soft display, which consists of dielectric elastomer and photonic crystals that cover all of the features mentioned above and can achieve the color change dynamically and in situ, is reported. In addition to the above features, the angle-dependent characteristic and the excellent mechanical reliability make it a great candidate for the next generation of soft display. Finally, the vast applications of the present concept in a variety of fields are also prospected

Soft Display Using Photonic Crystals on Dielectric Elastomers

Soft display has been intensively studied in recent years in the wake of rapid development of a variety of soft materials. The currently existing solutions for translating the traditional hard display into the more convenient soft display mainly include light-emitting diodes, liquid crystals, quantum dots, and phosphors. The desired soft display should take the advantages of facile fabrication processes and cheap raw materials. Besides, the device should be colorful, nontoxic, and not only flexible but also stretchable. However, the foregoing devices may not own all of the desired features. Here, a new type of soft display, which consists of dielectric elastomer and photonic crystals that cover all of the features mentioned above and can achieve the color change dynamically and in situ, is reported. In addition to the above features, the angle-dependent characteristic and the excellent mechanical reliability make it a great candidate for the next generation of soft display. Finally, the vast applications of the present concept in a variety of fields are also prospected