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Review Citation - WoS: 65Citation - Scopus: 73Micro Tool Design and Fabrication: a Review(Elsevier Sci Ltd, 2018) Oliaei, S. N. B.; Karpat, Y.; Paulo Davim, J.; Perveen, A.Mechanical micromachining is considered as a cost-effective and efficient fabrication technique to produce three dimensional features and free-form surfaces from various engineering materials. Micro cutting tools are an essential part of mechanical micromachining and they are exposed to harsh conditions which reduces tool life and adversely affect the economics of the process. The challenge is therefore to maintain the tool rigidity and cutting edge sharpness for extended period of time. Thus, the design, fabrication and durability of micro cutting tools are of significant importance for successful micromachining operations. This review paper aims to provide a comprehensive understanding about the capabilities, characteristics, and limitations of different fabrication techniques used in the manufacturing of micro cutting tools. State-of-the-art micro cutting tool design and coating technology has been presented for various micromachining applications. Possible future research direction and development in the field of micro tool design and fabrication has also been discussed.Article Citation - WoS: 3Citation - Scopus: 3Optical Analysis of Ge/Mgo and Ge/Bn Thin Layers Designed for Terahertz Applications(Elsevier Sci Ltd, 2015) Al Garni, S. E.; Qasrawi, A. F.In this work, a 200 nm Ge thin film is used as a substrate to design Ge/MgO and Ge/BN layers. The optical dynamics in these devices are investigated by means of the reflectivity and the transmissivity measurements. Particularly, the details of the dielectric spectra and the values of the energy band gaps (E-g) are investigated. Below 350 THz, the construction of Ge/MgO and Ge/BN interfaces decreased the effective dielectric constant of Ge by 39% and by 76%, respectively. It also increased the quality factor of the Ge optical device from 150 to 1400 and to 940 at 300 THz. All the dispersive optical parameters are also evaluated. In addition, the direct/indirect E-g value of Ge which was determined as 1.15/0.72 eV is observed to shift down by a 0.13/0.42 and by a 023/0.54 eV for the Ge/MgO and Ge/BN devices, respectively. The sharp increase in the dielectric constant with decreasing frequency in the range of 353 273 THz, the dispersive optical parameters and the energy band gap attenuations of the optical structures are promising as they indicate the applicability of the Ge, Ge/MgO and Gel BN layers in terahertz sensing. The latter technology has a wide range of applications like medical and telecommunication devices. (C) 2014 Elsevier Ltd. All rights reserved.Article Citation - WoS: 11Citation - Scopus: 11Optical and Electrical Performance of Yb/Inse Interface(Elsevier Sci Ltd, 2016) Alharbi, S. R.; Qasrawi, A. F.In this study a 300 nm ytterbium transparent thin film is used as substrate to a 300 nm thick InSe thin film. The optical transmittance, reflectance and absorbance of the glass/InSe and Yb/InSe films are measured and analyzed. The optical data allowed determining the effects of the Yb layer on the energy band gap, on the dielectric and on optical conductivity spectra. The band gap of the InSe films shrunk from 2.38/139 to 1.90/1.12 eV upon Yb layer interfacing leading to a band offset of 0.48/0.27 eV. On the other hand, the modeling of the optical conductivity in accordance with the Lorentz theory revealed a free carrier scattering time, carrier density and mobility of 0.225 (fs), 3.0 x 10(19)(cm(-3)) and 2.53 cm(2)/Vs for the Yb/InSe interface, respectively. As these values seem to be promising for employing the Yb/InSe interface in thin film transistor technology, the current voltage characteristics of Yb/InSe/C Schottky diode were recorded and analyzed. The electrical analysis revealed the removal of the tunneling channels by using Yb in place of Al. In addition, the "on/off' current ratios, the Schottky barrier height and the switching voltage of the Yb/InSe/C device are found to be 18.8, 0.76/0.60 eV and 0.53 V, respectively. (C) 2015 Elsevier Ltd. All rights reserved.
