Micro-convection is a strategic area in transport phenomena, since it is the basis for a wide range of miniaturised high-performance applications. Microchannel heat-sinks are appealing solutions to the increasing heat dissipation demands, especially in electronic devices. Literature reveals that in the single-phase continuum regime, the behaviour of micro-convection significantly differs from t...

A versatile, fast, and nature-inspired polyphenol chemistry surface modification was applied to prepare superhydrophobic surfaces with micro-grooved structures in this study. Tannic acid and iron ion (TA–FeIII) complexes were employed as a molecular building block for anchoring biomimetic coating onto the wood substrate with catalytically reducing formative Ag ions as the rough surface to ensur...

Demands are increasing for micro axis-symmetric aspherical lenses to be installed in various optical devices. The micro glass lenses are generally molded by glass press process with micro aspheric ceramic molding dies or molds made of tungsten carbide or silicon carbide. These dies and molds are mostly ground with micro diamond wheels, but require additional finishing process as the size of the...

Extraordinary water-repelling properties of superhydrophobic surfaces make them novel candidates for a great variety of potential applications. A general approach to achieve superhydrophobicity requires low-energy coating on the surface and roughness on nano- and micrometre scale. However, typical construction of superhydrophobic surfaces with micro-nano structure through top-down fabrication i...

This paper reports on the evaluation of a high resolution micro ultrasonic machining (HR-μUSM) process suitable for post fabrication trimming of complex 3D microstructures made from fused silica. Unlike conventional USM, the HR-μUSM process aims for low machining rates, providing high resolution and high surface quality. The machining rate is reduced by keeping the micro-tool tip at a fixed dis...

The interaction of 180 fs, 775 nm laser pulses with aluminium under a flowing stream of helium at ambient pressure have been used to study the material re-deposition, ablation rate and residual surface roughness. Threshold fluence Fth 0:4 J cm 2 and the volume ablation rate was measured to be 30 < V < 450 mm per pulse in the fluence range 1:4 < F < 21 J cm . The presence of helium avoids gas br...

We analyze the focusing properties of Fresnel zone plates fabricated over steel tapes using laser ablation. Our intention is to implement the use of micro-optical elements when the use of conventional chrome-glass elements is not indicated. Because of the manufacture process, the surface presents a certain anisotropic roughness, which reduces the focusing properties. First, we develop numerical...

This work focuses on control of surface roughness in sputtering processes including two surface micro-processes, diffusion and erosion. The fluctuation of surface height of such sputtering processes can be described by the stochastic Kuramoto–Sivashinsky equation (KSE), a fourth-order stochastic partial differential equation (PDE). Specifically, we consider sputtering processes, including surfa...

In this paper, dry etching of silicon micro-trenches were completed with a time multiplexed inductively coupled plasma (ICP) etcher. By change the time of etching and passivation cycles, applied electrode and coil powers, gas flow rates and the gas flow overlap due to the finite time response of the mass flow controllers, the etch rate of silicon and mask materials, aspect ratio, the profiles o...

Line edge roughness is an important factor contributing to the problem of performance degradation in various nanoscale devices. We have developed two smoothing techniques based on nanoimprint lithography for the fabrication of nanoscale gratings with significantly reduced line edge roughness. Compared with other smoothing techniques reported before, our methods are low-cost, effective, and easy...