Influences of Specimen Size and Annealing Temperature on Mechanical Reliability of FIB-Fabricated Si Nanowires for NEMS

2013 ◽  
Author(s):  
Tatsuya Fujii ◽  
Koichi Sudoh ◽  
Shozo Inoue ◽  
Takahiro Namazu
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Ion Beam ◽  
High Vacuum ◽  
Specimen Size ◽  
Film Deposition ◽  
Uniaxial Tensile ◽  
Si Nanowires ◽  
Uniaxial Tensile Testing ◽  
The Mean

This paper describes the effects of specimen size, focused ion beam (FIB) induced damage, and annealing on the mechanical properties of sub-100nm-sized silicon (Si) nanowires (NWs) that were evaluated by means of uniaxial tensile testing. Si NWs were made from silicon-on-nothing membranes that were produced by deep reactive ion etching trench fabrication and ultra-high vacuum (UHV) annealing. FIB system’s probe manipulation and film deposition functions were used to fabricate Si NWs and to directly bond them onto the sample stage of a tensile test device. The mean Young’s modulus and the mean strength of FIB-damaged NWs were 131.0 GPa and 5.6 GPa, respectively. After 700°C and 1000°C annealing in UHV, the mean Young’s modulus was increased to 168.1 GPa and 169.4 GPa, respectively, due to recrystallization by annealing. However, the mean strength was decreased to 4.1 GPa and 4.0 GPa, respectively. These experimental facts imply that the crystallinity of NWs improved, but the morphology was degraded. The surface degradation was probably related to gallium ion implantation into NWs surface during FIB fabrication.

Focused Ion Beam Induced Surface Damage Effect on the Mechanical Properties of Silicon Nanowires

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Tatsuya Fujii ◽  
Takahiro Namazu ◽  
Koichi Sudoh ◽  
Shouichi Sakakihara ◽  
Shozo Inoue
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Focused Ion Beam ◽  
Young's Modulus ◽  
Ion Beam ◽  
Surface Damage ◽  
Ambient Air ◽  
Film Deposition ◽  
Displacement Sensor ◽  
Uniaxial Tensile

In this paper, the effect of surface damage induced by focused ion beam (FIB) fabrication on the mechanical properties of silicon (Si) nanowires (NWs) was investigated. Uniaxial tensile testing of the NWs was performed using a reusable on-chip tensile test device with 1000 pairs of comb structures working as an electrostatic force actuator, a capacitive displacement sensor, and a force sensor. Si NWs were made from silicon-on-nothing (SON) membranes that were produced by deep reactive ion etching hole fabrication and ultrahigh vacuum annealing. Micro probe manipulation and film deposition functions in a FIB system were used to bond SON membranes to the device's sample stage and then to directly fabricate Si NWs on the device. All the NWs showed brittle fracture in ambient air. The Young's modulus of 57 nm-wide NW was 107.4 GPa, which was increased to 144.2 GPa with increasing the width to 221 nm. The fracture strength ranged from 3.9 GPa to 7.3 GPa. By assuming the thickness of FIB-induced damage layer, the Young's modulus of the layer was estimated to be 96.2 GPa, which was in good agreement with the literature value for amorphous Si.

Characterization of Hard Coatings Modified with Nitrogen Implantation

2010 ◽  
Vol 297-301 ◽  
pp. 1027-1036
Author(s):  
Branko Skoric ◽  
Damir Kakas ◽  
Aleksansar Miletic
Keyword(s):  
Ion Implantation ◽  
Young’S Modulus ◽  
Crystallographic Orientation ◽  
Vapour Deposition ◽  
Young's Modulus ◽  
Ion Beam ◽  
Film Deposition ◽  
Hard Coatings ◽  
Ion Beam Assisted Deposition ◽  
Nanoindentation Technique

In this paper, we present results of a study of TiN films which are deposited by Physical Vapor Deposition and Ion Beam Assisted Deposition. In the present investigation the subsequent ion implantation was provided with N2+ ions. The ion implantation was applied to enhance the mechanical properties of the surface. The film deposition process exerts a number of effects such as crystallographic orientation, morphology, topography, densification of the films. The evolution of the microstructure from porous and columnar grains to densely packed grains is accompanied by changes in mechanical and physical properties. A variety of analytic techniques were used for characterization, such as scratch test, calo test, SEM, AFM, XRD and EDAX. The experimental results indicated that the mechanical hardness is elevated by penetration of nitrogen, whereas the Young’s modulus is significantly elevated. Thin hard coatings deposited by physical vapour deposition (PVD), e.g. titanium nitride (TiN) are frequently used to improve tribological performance in many engineering applications. Ion bombardment during vapour deposition of thin films, colled ion beam assisted deposition (IBAD), exerts a number of effects such as densification, changes in grain size, crystallographic orientation, morphology and topography of the films. This paper describes the successful use of the nanoindentation technique for determination of hardness and elastic modulus. In the nanoindentation technique, hardness and Young’s modulus can be determined by the Oliver and Pharr method. Therefore, in recent years, a number of measurements have been made in which nanoindentation and AFM have been combined.

scholarly journals Atomic Simulations of Packing Structures, Local Stress and Mechanical Properties for One Silicon Lattice with Single Vacancy on Heating

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3127
Author(s):  
Feng Dai ◽  
Dandan Zhao ◽  
Lin Zhang
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Silicon Crystal ◽  
Local Stress ◽  
Uniaxial Tensile ◽  
Single Vacancy ◽  
Vacancy Defects ◽  
Silicon Lattice ◽  
Atomic Simulations

The effect of vacancy defects on the structure and mechanical properties of semiconductor silicon materials is of great significance to the development of novel microelectronic materials and the processes of semiconductor sensors. In this paper, molecular dynamics is used to simulate the atomic packing structure, local stress evolution and mechanical properties of a perfect lattice and silicon crystal with a single vacancy defect on heating. In addition, their influences on the change in Young’s modulus are also analyzed. The atomic simulations show that in the lower temperature range, the existence of vacancy defects reduces the Young’s modulus of the silicon lattice. With the increase in temperature, the local stress distribution of the atoms in the lattice changes due to the migration of the vacancy. At high temperatures, the Young’s modulus of the silicon lattice changes in anisotropic patterns. For the lattice with the vacancy, when the temperature is higher than 1500 K, the number and degree of distortion in the lattice increase significantly, the obvious single vacancy and its adjacent atoms contracting inward structure disappears and the defects in the lattice present complex patterns. By applying uniaxial tensile force, it can be found that the temperature has a significant effect on the elasticity–plasticity behaviors of the Si lattice with the vacancy.

Cellulose Whiskers Micro-Fibers Effect in the Mechanical Proprieties of PP and PLA Composites Fibers Obtained by Spinning Process

2011 ◽  
Vol 146 ◽  
pp. 12-26 ◽  
Author(s):  
A. Gherissi ◽  
R.Ben Cheikh ◽  
E. Dévaux ◽  
Fethi Abbassi
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Volume Fraction ◽  
Young's Modulus ◽  
Tensile Tests ◽  
Advanced Materials ◽  
Uniaxial Tensile ◽  
Failure Resistance ◽  
Cellulose Whiskers ◽  
Limit Strength

In this study, we present the manufacturing process of two new composites materials in the form of long fibers of polylactic-acid (PLA) or polypropylene (PP), reinforced by cellulose whiskers micro-fibers loads. In order to evaluate the mechanical properties of these advanced materials, a several uniaxial tensile tests were carried out. The PP and the PLA have initially been spinning without the addition of cellulose whiskers micro-fibers. In order to study the effects of cellulose whiskers micro-fibers reinforcements in the Mechanical behavior of the PLA and PP filaments, we determinate the proprieties of these advanced material from the tensile results. For the PP composite filaments material case, the whiskers reinforcement increases Young's modulus and failure resistance, but it reduces the limit strength failure. For the PLA composites the addition of 1% wt of cellulose whiskers from the total volume fraction of the material, increase the Young’s modulus more than 50% and a decrease of the failure resistance and the limit strength of composite. The obtained composites fibers are very rigid and brittle. What follows, that the addition of cellulose whiskers micro fibers in PP matrix, provides mechanical properties more convenient compared to the PLA matrix.

EFFECT OF SPECIMEN SIZE ON YOUNG'S MODULUS OF ELECTRODEPOSITED Ni

2009 ◽  
Vol 16 (02) ◽  
pp. 303-307 ◽  
Author(s):  
HONG WANG ◽  
RUI LIU ◽  
SHENG-PING MAO ◽  
JUN TANG ◽  
CONG-CHUN ZHANG ◽  
...  
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Specimen Size ◽  
Young’S Moduli ◽  
Different Dimensions

The Young's moduli of electrodeposited Ni with different dimensions were measured carefully in this paper. The dimensions of tensile specimens were 200, 35, or 5 μm thick and 2400, 200 or 50 μm wide. These specimens were measured with three different approaches. The measured Young's moduli of Ni decrease from 122.1 ± 4.3 to 92 ± 5.2 GPa when the thickness changes from 200 to 5 μm and width changes from 2400 to 50 μm.

Stiffening Effects of Tubes in Heat Exchanger Tubesheet

1984 ◽  
Vol 106 (3) ◽  
pp. 237-246 ◽  
Author(s):  
T. Terakawa ◽  
A. Imai ◽  
K. Yagi ◽  
Y. Fukada ◽  
K. Okada
Keyword(s):  
Heat Exchanger ◽  
Young’S Modulus ◽  
Tube Wall ◽  
Young's Modulus ◽  
Perforated Plate ◽  
Load Condition ◽  
Experimental Tests ◽  
Uniaxial Tensile ◽  
Hydraulic Test ◽  
Tube Heat Exchanger

Strain-measuring tests were performed with strain gages on rectangular coupons taken from perforated plate with triangular pitch under both uniaxial tensile loads and pure bending loads. The effective Young’s modulus obtained from the tests have strong correlation with the values recommended by the ASME Code. Next, to evaluate the stiffening effects of tubes, similar strain-gage tests were performed for different types of perforated coupons. One type had the tubes strength welded into the penetration holes of the test coupons. Another type had the tubes both expanded and strength welded into the test coupons. Stiffening effects of tubes are clearly obtained from these tests. Judging from the effective Young’s modulus of triangular pitch obtained by the testing, the recommended minimum credit given to the tube wall is 50 percent under elastic load condition. In addition, for experimental tests on an actual large-sized shell-and-tube heat exchanger under hydraulic test condition, good correlation was obtained between calculated and measured stress when full credit was taken for the tube wall in the calculation.

Study the Strength of Material and Composite Structures of Belly-Landing Mini UAV

2016 ◽  
Vol 842 ◽  
pp. 178-185 ◽  
Author(s):  
Maria Fransisca Soetanto ◽  
Rachmad Imbang Tritjahjono
Keyword(s):  
Tensile Strength ◽  
Composite Materials ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Von Mises Stress ◽  
Uniaxial Tensile ◽  
Specific Strength ◽  
Specific Stiffness ◽  
Von Mises ◽  
Material Composite

This paper consists of the design and analysis of the strength of material composite of the fuselage of a Belly-Landing Mini Unmanned Aerial Vehicle (UAV). A belly landing UAV occurs when an UAV lands without its landing gear and uses its underside, or belly, as its primary landing device. Belly landings carry the risk that the UAV may flip over, disintegrate, or catch fire if it lands too fast or too hard [1], so the more important designs parameters for materials used are the specific strength and specific stiffness. Specific strength is defined as the ultimate tensile strength divided by material density, and specific stiffness is defined as Young’s modulus of the material divided by density [Franklin, 2010]. The aim of this Belly Landing Mini UAV is for used in situations where manned flight is considered too risky or difficult and no runway for take-off or landing, such as fire fighting surveillance, while the term 'mini’ means the design of this UAV has a launch mass greater than 100 grams but less than 100 kilograms [2], the objective of this project is the development and design of materials fuselage of a mini UAV with two layer sandwich structures made from composite materials and epoxy resin. For that purposes, 3 variations of the composite materials tensile test specimens have been manufactured in accordance with ASTM D3039 standard and tested its strength. The results showed that the fibre glass and fibre carbon composite with resin epoxy has the maximum tensile strength and Young’s modulus, so that the fabrication and manufacturing of the fuselage component is made by using that material composite. The Von Mises stress is used to predict yielding of materials under any loading condition from results of simple uniaxial tensile tests by using software Autodesk Inventor 2012. The results show that the design is safe caused the strength of material is greater than the maximum value of Von Mises stress induced in the material. The results of flight tests show that this small UAV has successfully manoeuvred to fly, such as take off, some acrobatics when cruising and landing smoothly, which means that the calculation and analysis of structure and material used on the fuselage of the Mini UAV was able to be validated.

Uncertainty quantification and prediction for mechanical properties of graphene aerogels via gaussian process metamodels

Nano Futures ◽  
2021 ◽  
Author(s):  
Bowen Zheng ◽  
Zeyu Zheng ◽  
Grace Gu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Gaussian Process ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Dynamics Simulation ◽  
Uniaxial Tensile ◽  
Graphene Aerogel ◽  
Graphene Aerogels

Abstract Graphene aerogels, a special class of 3D graphene assemblies, are well known for their exceptional combination of high strength, lightweightness, and high porosity. However, due to microstructural randomness, the mechanical properties of graphene aerogels are also highly stochastic, an issue that has been observed but insufficiently addressed. In this work, we develop Gaussian process metamodels to not only predict important mechanical properties of graphene aerogels but also quantify their uncertainties. Using the molecular dynamics simulation technique, graphene aerogels are assembled from randomly distributed graphene flakes and spherical inclusions, and are subsequently subject to a quasi-static uniaxial tensile load to deduce mechanical properties. Results show that given the same density, mechanical properties such as the Young’s modulus and the ultimate tensile strength can vary substantially. Treating density, Young’s modulus, and ultimate tensile strength as functions of the inclusion size, and using the simulated graphene aerogel results as training data, we build Gaussian process metamodels that can efficiently predict the properties of unseen graphene aerogels. In addition, statistically valid confidence intervals centered around the predictions are established. This metamodel approach is particularly beneficial when the data acquisition requires expensive experiments or computation, which is the case for graphene aerogel simulations. The present research quantifies the uncertain mechanical properties of graphene aerogels, which may shed light on the statistical analysis of novel nanomaterials of a broad variety.

Application of Shear Wave Elastography in the Diagnosis of Thyroid Nodules of Thyroid Imaging Report and Data System

2020 ◽  
Vol 10 (4) ◽  
pp. 864-867
Author(s):  
Jia Zheng ◽  
Xiaoxin Wang ◽  
Xianjing Han ◽  
Chunyan Li ◽  
Jianan Wang ◽  
...  
Keyword(s):  
Young’S Modulus ◽  
Shear Wave ◽  
Thyroid Nodules ◽  
Ultrasound Examination ◽  
Young's Modulus ◽  
Shear Wave Elastography ◽  
Diagnostic Value ◽  
Data System ◽  
Thyroid Imaging ◽  
The Mean

The purpose of this study is to explore whether shear wave elastography has diagnostic value in distinguishing benign and malignant thyroid imaging report and data system (TI-RADS) nodules, so as to provide more accurate information for clinical diagnosis and treatment of thyroid nodules. In this study, 134 patients with thyroid nodules who underwent ultrasound examination from February 2018 to October 2018 are collected. Firstly, according to the diagnostic criteria proposed by Horvath, TI-RADS grading is performed on them, and 78 patients with TI-RADS4 single solid nodules are screened out. Secondly, conventional ultrasound examination is performed on all the researchers, and shear wave elastographies are obtained 1 week after the examination. Thirdly, parameters of each lesion are measured by ultrasound physicians, and the maximum, minimum and average values of Young's modulus of each lesion are recorded. The results show that the mean and maximum of Young's modulus of benign lesions are (26.31 ± 9.88) kPa and (51.36 ± 14.51) kPa, respectively, the mean and maximum of Young's modulus of malignant lesions are (48.36 ± 16.53) and (69.15 ± 19.98) kPa, respectively, and the area under the ROC curve of Emean and Emax is 0.852 and 0.748, respectively. Therefore, shear wave elastography is a new type of ultrasound elastography, which has the advantages of objectivity and little influence from operators without artificial pressure. It has high sensitivity, specificity and accuracy in diagnosing benign and malignant thyroid nodules. Among them, the average value of Young's modulus has the greatest diagnostic value.

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