The purpose of this experiment is to explore the variables that affect the efficiency of a swimmer in the streamline position. There are various factors that affect the drag of a swimmer such as: the type of suit, wearing a cap or not, and the depth of the push off. The hydrophobicity of a fast suit and a regular suit was measured to show which one will be the most effective in the water. The c...

Nano-porous silicon were simply prepared from p-type single crystalline silicon wafer by electrochemical etching technique via exerting constant current density in two different HF-Ethanol and HF-Ethanol-H2O solutions. The mesoporous silicon layers were characterized by field emission scanning electron microscopy and scanning electron microscopy. The results demonstrate that the width of nano-p...

We present the enhanced wet etching of GaN epilayer implanted with Au+ ion. Patterned GaN with 2 microm-wide sink-like strips was achieved by using 500 keV Au+ ion implantation and KOH etching. The Dependence of etching depth on etching time for the implantation at different ion fluences was investigated. The experiment showed that the damaged GaN area could be almost etched out at high ion flu...

High speed directional etching of non conventional materials like Quartz, Lithium Niobate and Lead Titanate is still insufficiently developed for producing high aspect ratio microstructures. Compared to deep silicon etching, the plasma etching of these materials has suffered from limitations in achievable depth, aspect ratio, verticality and smoothness of surfaces. Deep etching with nearly vert...

background: the aim of this study was to compare the effects of conventional acid etching and laser etching on the nano-mechanical properties of the dental enamel using nano-indentation test. materials and methods: in this experimental in vitro study, buccal surfaces of 10 premolars were divided into three regions. one of the regions was etched with 37% phosphoric acid and another etched with e...

This paper presents processes for glass micromachining, including sandblast, wet etching, reactive ion etching (RIE), and glass reflow techniques. The advantages as well as disadvantages of each method are presented and discussed in light of the experiments. Sandblast and wet etching techniques are simple processes but face difficulties in small and high-aspect-ratio structures. A sandblasted 2...

A novel low-cost 2D silicon nano-mold fabrication technique was developed based on Cu inclined-deposition and Ar(+) (argon ion) etching. With this technique, sub-100 nm 2D (two dimensional) nano-channels can be etched economically over the whole area of a 4 inch n-type <100> silicon wafer. The fabricating process consists of only 4 steps, UV (Ultraviolet) lithography, inclined Cu deposition, Ar...

The optimization of etchant parameters in wet etching plays an important role in the fabrication of semiconductor devices. Wet etching of tetramethylammonium hydroxide (TMAH)/isopropyl alcohol (IPA) on silicon nanowires fabricated by AFM lithography is studied herein. TMAH (25 wt %) with different IPA concentrations (0, 10, 20, and 30 vol %) and etching time durations (30, 40, and 50 s) were in...