Room-Temperature Molding of Complex-Shaped Transparent Fused Silica Lenses.

The high hardness, brittleness, and thermal resistance impose significant challenges in the scalable manufacturing of fused silica lenses, which are widely used in numerous applications. Taking advantage of the nanocomposites by stirring silica nanopowders with photocurable resins, the newly emerged low-temperature pre-shaping technique provides a paradigm shift in fabricating transparent fused silica components. However, preparing the silica slurry and carefully evaporating the organics may significantly increase the process complexity and decrease the manufacturing efficiency for the nanocomposite-based technique.

Numerical Investigation on the Effects of Grain Size and Grinding Depth on Nano-Grinding of Cadmium Telluride Using Molecular Dynamics Simulation.

Cadmium telluride (CdTe) is known as an important semiconductor material with favorable physical properties. However, as a soft-brittle material, the fabrication of high-quality surfaces on CdTe is quite challenging. To improve the fundamental understanding of the nanoscale deformation mechanisms of CdTe, in this paper, MD simulation was performed to explore the nano-grinding process of CdTe with consideration of the effects of grain size and grinding depth.

Design and assessment of amblyopia, strabismus, and myopia treatment and vision training using virtual reality.

Background: Virtual reality is a relatively new intervention that has the potential to be used in the treatment of eye and vision problems. This article reviews the use of virtual reality-related interventions in amblyopia, strabismus, and myopia research.

Methods: Sources covered in the review included 48 peer-reviewed research published between January 2000 and January 2023 from five electronic databases (ACM Digital Library, IEEE Xplore, PubMed, ScienceDirect and Web of Science).

CMP Pad Conditioning Using the High-Pressure Micro-Jet Method.

In this study, in order to improve and restore the performance of the polishing pads and reduce the cost of chemical mechanical polishing, three types of material polishing pads, namely, polyurethane, damping cloth, and non-woven fabric, were selected for the experiment. Accordingly, each polishing pad was set up with diamond conditioner and high-pressure micro-jet (HPMJ) conditioning control experiments. Subsequently, the fluctuation ranges of the material removal rate on the three polishing pads were 2.

A critical analysis on the triple bottom line of sustainable manufacturing: key findings and implications.

Because of the environmental consequences of manufacturing activities, the general public, industry, and academia are becoming more aware of sustainable manufacturing (SM), which incorporates environmentally friendly manufacturing processes while emphasizing overall triple bottom line (TBL) performance in manufacturing. This article employs various text mining techniques and bibliometric analysis including cluster analysis, Pearson coefficient and research landscape to conduct an extensive investigation on SM with a focus on the TBL, in which the research content of SM with the TBL is reviewed and discussed systematically from a wide angle and with reduced bias. In this study, three new indicators about the ratios of the number of scientific papers between social, environmental, and economic dimensions of SM are devised to show the weight and level of importance of dimensions in SM, covering scientific papers from 30 years.

Discover the trend and evolution of sustainable manufacturing: a thematic and bibliometric analysis.

Manufacturing, as one of the most important sectors in a civilized society, has a strong impact on our city's sustainability issues, and it is therefore justified in taking a more sustainable approach in the future. As a consequence, research works and the research trend of sustainable manufacturing (SM) play a critical role in supporting the sustainable development of industries. With the knowledge of the research themes on SM from the past to the present, preferred options for planning the future of manufacturing and executing SM could be offered to industries.

Inhibiting the Leidenfrost effect above 1,000 °C for sustained thermal cooling.

The Leidenfrost effect, namely the levitation of drops on hot solids, is known to deteriorate heat transfer at high temperature. The Leidenfrost point can be elevated by texturing materials to favour the solid-liquid contact and by arranging channels at the surface to decouple the wetting phenomena from the vapour dynamics. However, maximizing both the Leidenfrost point and thermal cooling across a wide range of temperatures can be mutually exclusive.

Explosive Pancake Bouncing on Hot Superhydrophilic Surfaces.

The rapid detachment of liquid droplets from engineered surfaces in the form of complete rebound, pancake bouncing, or trampolining has been extensively studied over the past decade and is of practical importance in many industrial processes such as self-cleaning, anti-icing, energy conversion, and so on. The spontaneous trampolining of droplets needs an additional low-pressure environment and the manifestation of pancake bouncing on superhydrophobic surfaces requires meticulous control of macrotextures and impacting velocity. In this work, we report that the rapid pancake-like levitation of impinging droplets can be achieved on superhydrophilic surfaces through the application of heating.

Development of self-tuned diamond milling system for fabricating infrared micro-optics arrays with enhanced surface uniformity and machining efficiency.

Infrared micro-optics arrays (MOAs) featuring large numbers of micro-freeform lenslet are required increasingly in advanced infrared optical systems. Ultra-precision diamond cutting technologies have been widely used to fabricate MOAs with high form accuracy. However, the existing technologies can easily cause the non-uniformly fractured surface of infrared MOAs, due to the inherent low fracture toughness and high anisotropy of infrared materials as well as the time-varying chip thickness induced by ever-changing height and slope of the desired MOAs.

Flexible fabrication of micro-optics arrays with high-aspect-ratio by an offset-tool-servo diamond machining system.

Micro-optics arrays (MOAs) with high aspect ratio (AR) have unique advantages in realizing the minimization of optical systems by reducing the focal distance. Fast or slow tool servo (F/STS) is widely regarded as an outperforming technique for the fabrication of MOAs featuring high form accuracy. However, in the machining of MOAs with high AR, the non-smooth cutting trajectory of F/STS inevitably leads to intensive tool vibrations and the interference between the tool flank face and the finished surface, thereby deteriorating surface roughness.

Theoretical and Experimental Investigations of Tool Tip Vibration in Single Point Diamond Turning of Titanium Alloys.

The material swelling effect in single point diamond turning (SPDT) causes ragged materials on a machined surface which slows down the movements of tool tip vibration, and acts as a simple impacted pendulum system with a damping effect and displays a single twin peak in fast Fourier transform (FFT). Due to the low elastic modulus and low thermal conductivity of titanium alloys, the material swelling effect of titanium alloys in SPDT is much more serious than that of traditional metals. For this reason, the tool tip vibration in SPDT of titanium alloys is expected to be different from previous reports.

Serrated Chips Formation in Micro Orthogonal Cutting of Ti6Al4V Alloys with Equiaxial and Martensitic Microstructures.

The formation of serrated chips is an important feature during machining of difficult-to-cut materials, such as titanium alloy, nickel based alloy, and some steels. In this study, Ti6Al4V alloys with equiaxial and acicular martensitic microstructures were adopted to analyze the effects of material structures on the formation of serrated chips in straight line micro orthogonal machining. The martensitic alloy was obtained using highly efficient electropulsing treatment (EPT) followed by water quenching.

One-step generation of hybrid micro-optics with high-frequency diffractive structures on infrared materials by ultra-precision side milling.

Hybrid micro-optics of infrared (IR) materials are of great advantage in realizing the function integration and minimization of advanced IR optical systems. However, due to the hard-and-brittle nature of IR materials, it is still challenging for both non-mechanical and mechanical technologies to achieve one-step generation of hybrid infrared micro-optics with high form accuracy. In the present study, a flexible method, namely ultra-precision side milling (UPSM), is first introduced to achieve one-step generation of infrared hybrid micro-optics in ductile mode, and the corresponding reflective diffraction characteristics are analyzed.

Effect of Machining Parameters and Tool Wear on Surface Uniformity in Micro-Milling.

In micro-milling, the periodically varying chip thickness, which varies with tool rotation, leads to varying degrees of minimum chip thickness effect and ploughing effect during surface generation. This results in a change of roughness in the cross-sectional direction of the micro-grooves, giving a non-uniform surface quality. However, the factors influencing surface uniformity in micro-milling are not fully understood.

A Study of Mechanics in Brittle⁻Ductile Cutting Mode Transition.

This paper presents an investigation of the mechanism of the brittle⁻ductile cutting mode transition from the perspective of the mechanics. A mechanistic model is proposed to analyze the relationship between undeformed chip thickness, deformation, and stress levels in the elastic stage of the periodic chip formation process, regarding whether brittle or ductile mode deformation is to follow the elastic stage. It is revealed that, the distance of tool advancement required to induce the same level of compressive stress decreases with undeformed chip thickness, and thereby the tensile stress below and behind the tool decreases with undeformed chip thickness.

Active control of residual tool marks for freeform optics functionalization by novel biaxial servo assisted fly cutting.

The inherent residual tool marks (RTM) with particular patterns highly affect optical functions of the generated freeform optics in fast tool servo or slow tool servo (FTS/STS) diamond turning. In the present study, a novel biaxial servo assisted fly cutting (BSFC) method is developed for flexible control of the RTM to be a functional micro/nanotexture in freeform optics generation, which is generally hard to achieve in FTS/STS diamond turning. In the BSFC system, biaxial servo motions along the z-axis and side-feeding directions are mainly adopted for primary surface generation and RTM control, respectively.

Large-scale fabrication of micro-lens array by novel end-fly-cutting-servo diamond machining.

Fast/slow tool servo (FTS/STS) diamond turning is a very promising technique for the generation of micro-lens array (MLA). However, it is still a challenge to process MLA in large scale due to certain inherent limitations of this technique. In the present study, a novel ultra-precision diamond cutting method, as the end-fly-cutting-servo (EFCS) system, is adopted and investigated for large-scale generation of MLA.

Adaptive tool servo diamond turning for enhancing machining efficiency and surface quality of freeform optics.

Fast tool servo/ slow tool servo (FTS/STS) diamond turning is a very promising technique for the generation of freeform optics. However, the currently adopted constant scheme for azimuth sampling and side-feeding motion possesses no adaptation to surface shape variation, leading to the non-uniform surface quality and low machining efficiency. To overcome this defect, this paper reports on a novel adaptive tool servo (ATS) diamond turning technique which is essentially based on the novel two-degree-of-freedom (2-DOF) FTS/STS.

Effect of assembling errors on the diffraction efficiency for multilayer diffractive optical elements.

Based on the expression function of diffraction efficiency, and the phase delay function of diffractive optical elements (DOEs), the diffraction efficiency for multilayer diffractive optical elements (MLDOEs) is described with tilt and decenter assembling errors. A mathematical model of the relationship between diffraction efficiency and assembling errors of MLDOEs is proposed to analyze the effect of assembling errors on the diffraction efficiency of MLDOEs. The analyzed results from the mathematical model provide a range of values for the effect of assembling errors on the diffraction efficiency of MLDOEs.