Recent research progress of master mold manufacturing by nanoimprint technique for the novel microoptics devices

The consumer demand for emerging technologies such as augmented reality(AR),autopilot,and three-dimensional(3D)internet has rapidly promoted the application of novel optical display devices in innovative industries.However,the micro/nanomanufacturing of high-resolution optical display devices is the primary issue restricting their development.The manufacturing technology of micro/nanostructures,methods of display mechanisms,display materials,and mass production of display devices are major technical obstacles.To comprehensively understand the latest state-of-the-art and trigger new technological breakthroughs,this study reviews the recent research progress of master molds produced using nanoimprint technology for new optical devices,particularly AR glasses,new-generation light-emitting diode car lighting,and naked-eye 3D display mechanisms,and their manufacturing techniques of master molds.The focus is on the relationships among the manufacturing process,microstructure,and display of a new optical device.Nanoimprint master molds are reviewed for the manufacturing and application of new optical devices,and the challenges and prospects of the new optical device diffraction grating nanoimprint technology are discussed.

A computational model for capturing the distinct in-and out-of-plane response of lipid membranes

A computational framework was developed to capture the combined fluid-and solid-like behavior of lipid membranes in a unified manner.Specifically,the in-plane diffusion of lipid molecules and the associated evolution of membrane tension were explicitly taken into account in the model.In addition,the out-of-plane movement induced bending and shearing of membrane,along with its thermal undulations caused by bombardment of medium molecules,were also considered.The capability and validity of this approach were demonstrated by simulating the enforced deformation and shape fluctuations of a lipid vesicle under a variety of testing conditions as well as their comparison with corresponding theoretical predictions.Our model could serve a useful platform for investigating processes such as cell spreading and division where morphology evolution of the membrane and transport of lipids/transmembrane proteins are known to play key roles.

Hydrogen Ion Implantation Induced Cutting Behavior Variation in Plunge Cutting of the Monocrystalline Silicon

In this study,surface modification of monocrystalline silicon with two doses of hydrogen ion implantation and the plunge cutting process were conducted to explore the influence of hydrogen ions on the cutting behavior of silicon.The results show that ion implantation is capable of deteriorating or improving the machinability of silicon,depending on the implantation dose.More cleavages and a reduction of critical depth of cut(CDoC)were observed for the silicon with a low implantation dose in the cutting direction of<100>in comparison to bare silicon,while no cleavage and an increase of CDoC were achieved after implantation with a high dose in the same cutting direction.Besides,the ductile cutting and thrust forces of the silicon with the low dose are larger than the bare silicon,but the forces are significantly reduced for the silicon after the high dose of implantation.The variation of the cutting forces is due to the different required stresses to overcome ductile and fracture deformation of silicon.

Unveiling the Mechanism Behind the Asymmetric Bending Compliance of Thin-Walled U-Shaped Strips:A Study Inspired by Plant Leaves

Inspired by the shape of some plant leaves,we find that the thin-walled U-shaped strips exhibit different compliances under bending with opposite orientations.The asymmetric bending compliance is attributed to the buckling of sidewalls of strips caused by the bending-induced compression.Integrating the Euler-Bernoulli beam theory with the Kirchhoff-Love thin plate theory,a theoretical model is derived for the in-depth understanding of the sidewall buckling.For pure bending,the critical moment applied to the strip for the sidewall buckling is found to be insensitive to the height,width and length of strip,which is the result of the compromise between the opposite geometric effects on the buckling behavior of sidewalls and the characteristics of cross sections.Then the critical moment can be approximated as a linear function of flexural rigidity DEt^(3)/12(1-ν^(2)),where t is the wall thickness of strip,E is Young’s modulus,and v is Poisson’s ratio.These predictions by our model agree well with the results obtained by finite element analysis.We also investigate the buckling behavior of sidewalls for bending under transverse loads,considering the loading conditions of concentrated force and distributed force.Our study unveils the mechanism behind the asymmetric bending compliance of thin-walled U-shaped strips.These results would offer convenient guidance for the promising engineering applications related to this structure,such as the design of soft robots with enhanced locomotion performance.

Hydrophilic polyanionic hydrogel electrolyte for anti-freezing and bending resistant zinc-ion hybrid supercapacitors

Zinc-ion hybrid supercapacitors(ZHSCs)have been widely considered as promising candidates for flexible electrochemical energy storage devices.The key challenge is to develop hydrogel electrolytes with high hydrophilicity,anti-freezing,bending resistance,and stable interface with electrodes.This study reported a hydrogel electrolyte system that can meet the above functions,in which the zincophilic and negatively charged SO_(3)^(−),migratable Na^(+),abundant hydrophilic functional groups,gum xanthan,and porous architecture could effectively promote the electrochemical performance of ZHSCs.ZHSCs with such hydrogel electrolytes not only exhibited good low-temperature performance but also showed excellent bending resistance ability.A high specific capacitance could be kept after a long air-working lifespan over 10,000 cycles under a wide operation voltage of 1.85 V at−10℃.Furthermore,flexible ZHSCs could maintain the capacitance retention of 93.18%even after continuous 500 bends at an angle of 180°.The designed hydrogel electrolytes could be also used for other electrochemical energy storage devices with anti-freezing and bending resistance by changing electrolyte salt.