The laser-induced chemical etching mechanism of Cr–O doped GaAs (1 0 0) substrate in 40% HF-H2O solution is explained by the generation of e–h pairs through defect states in the presence of sub-bandgap photon illumination by using a Nd:YAG Laser (λ ∼ 1.06 m). The central feature of the laser etching technique is pits initiation by surface defects. The etched GaAs samples are characterised by ph...

Although the U.S. has studied space suit performance for decades, relatively little is known about how the astronaut moves and interacts within the space suit. We propose the use of insuit sensor systems to characterize this interaction and present our results using pressure sensors and inertial measurement units (IMUs) inside the David Clark Mobility Mock-Up and the Mark III space suit from NA...

Silicon microneedle arrays (MNAs) have been widely studied due to their potential in various transdermal applications. However, discrete MNAs, as a preferred choice to fabricate flexible penetrating devices that could adapt curved and elastic tissue, are rarely reported. Furthermore, the reported discrete MNAs have disadvantages lying in uniformity and height-pitch ratio. Therefore, an improved...

In a continuous quest for cost reduction, the semiconductor industry continues to pursue device scaling techniques. However as scaling becomes more complex and expensive, alternative techniques for cost reduction are being investigated. Progress in 3D packaging (3D-SIC, 3D-SoC) and Interposer technologies have the promise to offer reduced costs and smaller form factors. One of the key features ...

In this paper, we study the electrochemical anodization of n-type heavily doped 4 H-SiC wafers in a HF-based electrolyte without any UV light assistance. We present, in particular, the differences observed between the etching of Si and C faces. In the case of the Si face, the resulting material is mesoporous (diameters in the range of 5 to 50 nm) with an increase of the 'chevron shaped' pore de...

A multi-step plasma etching technique is developed to obtain deep-grooved micro-scale ball-bearing raceways and employed in the fabrication of multiple ball-bearing supported microturbines. Deep-groove geometry has been chosen for the microball-bearing systems because of the ability to handle mixed axial and radial loads, allowing for stable, high-speed operation compared to previous iterations...

We describe the fabrication of three-dimensional photonic crystals using a reproducible and reliable procedure consisting of electron beam lithography followed by a sequence of dry etching steps. Careful fabrication has enabled us to define photonic crystals with 280 nm holes defined with 350 nm center to center spacings in GaAsP and GaAs epilayers. We construct these photonic crystals by trans...