Pub Date : 2003-12-01DOI: 10.1142/S1465876303002209
M. K. Mawlood, W. Asrar, A. Omar, Megat M. H. M. Ahmad
An accurate numerical method is developed for computing inviscid flows containing discontinuities. The method is based on flux vector splitting (FVS) and a third-order accurate upwind-biased compact finite-difference scheme. Two different flux splitting techniques, namely, the kinetic flux vector splitting (KFVS) and van Leer's flux splitting, are used to solve one-dimensional gas dynamics test problems. The idea of total variation diminishing (TVD) is employed to suppress spurious numerical oscillations. The stability and high-order accuracy of the scheme are shown.
{"title":"An accurate scheme for gas dynamical calculations","authors":"M. K. Mawlood, W. Asrar, A. Omar, Megat M. H. M. Ahmad","doi":"10.1142/S1465876303002209","DOIUrl":"https://doi.org/10.1142/S1465876303002209","url":null,"abstract":"An accurate numerical method is developed for computing inviscid flows containing discontinuities. The method is based on flux vector splitting (FVS) and a third-order accurate upwind-biased compact finite-difference scheme. Two different flux splitting techniques, namely, the kinetic flux vector splitting (KFVS) and van Leer's flux splitting, are used to solve one-dimensional gas dynamics test problems. The idea of total variation diminishing (TVD) is employed to suppress spurious numerical oscillations. The stability and high-order accuracy of the scheme are shown.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129930153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-12-01DOI: 10.1142/S1465876303002180
K. Park, P. K. Banerjee
A particular integral formulation is presented for purely axisymmetric transient potential flow (heat conduction) analysis. The axisymmetric steady-state heat conduction equation is used as the complementary solution and the particular integrals for temperature and flux are derived by integrating the recently published three-dimensional formulation along the circumferential direction to obtain the required formulation involving elliptic integrals. The numerical results for three example problems are given and compared with their analytical solutions. Generally, agreement among all of those results is satisfactory, if a few interior points are added to the system equations along with the usual boundary points.
{"title":"Axisymmetric transient heat conduction analysis by bem via particular integrals","authors":"K. Park, P. K. Banerjee","doi":"10.1142/S1465876303002180","DOIUrl":"https://doi.org/10.1142/S1465876303002180","url":null,"abstract":"A particular integral formulation is presented for purely axisymmetric transient potential flow (heat conduction) analysis. The axisymmetric steady-state heat conduction equation is used as the complementary solution and the particular integrals for temperature and flux are derived by integrating the recently published three-dimensional formulation along the circumferential direction to obtain the required formulation involving elliptic integrals. The numerical results for three example problems are given and compared with their analytical solutions. Generally, agreement among all of those results is satisfactory, if a few interior points are added to the system equations along with the usual boundary points.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123143964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-12-01DOI: 10.1142/S1465876303002210
L. Zovatto, M. Nicolini
A new methodology for the solution of discrete conservation laws, based on a point by point approach, is presented. For each node, a local mesh is firstly generated, made up of all triangles whose vertices coincide with the node itself and its neighbours. The solution is then determined through mass, energy and momentum balances directly written in a discrete form over a tributary region, represented by the polygon whose vertices are the barycenters and/or the circumcenters of the triangles belonging to the local mesh. This approach avoids global mesh generation (computationally much more expensive), and is particularly efficient for non-linear problems, such as fracture mechanics. In the paper, the numerical method is described in detail for Laplace equation, together with the convergence order as a function of the number of nodes and the type of boundary conditions. Finally, in order to further simplify the procedure, it is proposed to consider the tributary area formed by the circle with center in the generic node and radius equal to the average of the distances between the node and its neighbours. This results in a considerable ease in writing the discrete form of the governing equations, while maintaining the same accuracy and order of convergence than the approach based on local triangles.
{"title":"The meshless approach for the cell method: a new way for the numerical solution of discrete conservation laws","authors":"L. Zovatto, M. Nicolini","doi":"10.1142/S1465876303002210","DOIUrl":"https://doi.org/10.1142/S1465876303002210","url":null,"abstract":"A new methodology for the solution of discrete conservation laws, based on a point by point approach, is presented. For each node, a local mesh is firstly generated, made up of all triangles whose vertices coincide with the node itself and its neighbours. The solution is then determined through mass, energy and momentum balances directly written in a discrete form over a tributary region, represented by the polygon whose vertices are the barycenters and/or the circumcenters of the triangles belonging to the local mesh. This approach avoids global mesh generation (computationally much more expensive), and is particularly efficient for non-linear problems, such as fracture mechanics. In the paper, the numerical method is described in detail for Laplace equation, together with the convergence order as a function of the number of nodes and the type of boundary conditions. Finally, in order to further simplify the procedure, it is proposed to consider the tributary area formed by the circle with center in the generic node and radius equal to the average of the distances between the node and its neighbours. This results in a considerable ease in writing the discrete form of the governing equations, while maintaining the same accuracy and order of convergence than the approach based on local triangles.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124966905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-12-01DOI: 10.1142/S1465876303002192
J. C. Ong, A. Omar, W. Asrar
In this paper, two classes of gas-kinetic schemes are investigated for one-dimensional compressible inviscid flow, namely, the Kinetic Flux Vector Splitting (KFVS) scheme and the Bhatnagar-Gross-Krook (BGK) scheme. Second-order high-resolution scheme for both methods are also developed for calculating flows containing discontinuities. This is achieved by means of reconstructing the initial data via Monotone Upstream-Centered Schemes for Conservation Laws (MUSCL) approach. The Total Variation Diminishing (TVD) shock capturing properties of these second-order schemes are achieved through the use of non-linear limiters. In addition, a multistage TVD Runge-Kutta method is employed for the time integration of the finite volume gas-kinetic scheme. Exclusive consideration is focused on the BGK scheme, which yields a better numerical result in comparison with the KFVS scheme. Three typical one-dimensional inviscid flow problems containing shocks, namely, steady flow in a divergent nozzle, the unsteady shock tube problem, and two interacting blast waves problem are analyzed numerically with the gas-kinetic schemes. Numerical results from the first-order and second-order gas-kinetic schemes are presented and compared with the exact solutions. Other computed results such as those from the Steger-Warming's Flux Vector Splitting scheme, Roe's Flux Difference Splitting scheme, MacCormack's scheme, and high-order compact Van Leer's Flux Splitting Scheme are also presented as comparisons to the gas-kinetic schemes. In addition, the effects of grid sizes on the numerical results of the gas-kinetic schemes are also investigated.
{"title":"Evaluation of gas-kinetic schemes for solving 1d inviscid compressible flow problems","authors":"J. C. Ong, A. Omar, W. Asrar","doi":"10.1142/S1465876303002192","DOIUrl":"https://doi.org/10.1142/S1465876303002192","url":null,"abstract":"In this paper, two classes of gas-kinetic schemes are investigated for one-dimensional compressible inviscid flow, namely, the Kinetic Flux Vector Splitting (KFVS) scheme and the Bhatnagar-Gross-Krook (BGK) scheme. Second-order high-resolution scheme for both methods are also developed for calculating flows containing discontinuities. This is achieved by means of reconstructing the initial data via Monotone Upstream-Centered Schemes for Conservation Laws (MUSCL) approach. The Total Variation Diminishing (TVD) shock capturing properties of these second-order schemes are achieved through the use of non-linear limiters. In addition, a multistage TVD Runge-Kutta method is employed for the time integration of the finite volume gas-kinetic scheme. Exclusive consideration is focused on the BGK scheme, which yields a better numerical result in comparison with the KFVS scheme. Three typical one-dimensional inviscid flow problems containing shocks, namely, steady flow in a divergent nozzle, the unsteady shock tube problem, and two interacting blast waves problem are analyzed numerically with the gas-kinetic schemes. Numerical results from the first-order and second-order gas-kinetic schemes are presented and compared with the exact solutions. Other computed results such as those from the Steger-Warming's Flux Vector Splitting scheme, Roe's Flux Difference Splitting scheme, MacCormack's scheme, and high-order compact Van Leer's Flux Splitting Scheme are also presented as comparisons to the gas-kinetic schemes. In addition, the effects of grid sizes on the numerical results of the gas-kinetic schemes are also investigated.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122853556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-09-01DOI: 10.1142/S1465876303001708
Shuhui Yu, K. Yao, F. Tay
Relaxor ferroelectric (1-x)Pb(Zn1/3Nb2/3)O3-xPbTiO3 is attractive for many electromechanical transducer applications due to its very large piezoelectric responses, and high electromechanical coupling factor. An oriented PZN-xPT film is particularly desired to achieve further enhanced piezoelectric performance. However, it is difficult to obtain pure ferroelectric perovskite phase in a PZN-xPT thin film because of the preferential formation of detrimental pyrochlore phase. In this paper, perovskite PZN-xPT thin films were prepared by a sol-gel method on (100) Si substrates. A (100)-oriented perovskite LaNiO3 (LNO) thin film was deposited as both the bottom electrode and seeding layer; and a ZrO2 film was deposited as a buffer layer between the LNO film and the Si substrate. X-Ray Diffraction (XRD), and Scanning Electronic Microscopy (SEM) were used to examine the structure, orientation, and morphology of the PZN-xPT thin films. The dielectric and ferroelectric properties of the films were measured with an impedance analyzer and a standard ferroelectric testing system, respectively. The results showed that perovskite structure with (100) orientation was successfully obtained in the PZN-xPT films. The film exhibited a typical ferroelectric P-E hysteresis loop with a high remanent polarization.
{"title":"(100)-Oriented PZN-xpt Thin Films Grown On Lanio3 Seeding Layers","authors":"Shuhui Yu, K. Yao, F. Tay","doi":"10.1142/S1465876303001708","DOIUrl":"https://doi.org/10.1142/S1465876303001708","url":null,"abstract":"Relaxor ferroelectric (1-x)Pb(Zn1/3Nb2/3)O3-xPbTiO3 is attractive for many electromechanical transducer applications due to its very large piezoelectric responses, and high electromechanical coupling factor. An oriented PZN-xPT film is particularly desired to achieve further enhanced piezoelectric performance. However, it is difficult to obtain pure ferroelectric perovskite phase in a PZN-xPT thin film because of the preferential formation of detrimental pyrochlore phase. In this paper, perovskite PZN-xPT thin films were prepared by a sol-gel method on (100) Si substrates. A (100)-oriented perovskite LaNiO3 (LNO) thin film was deposited as both the bottom electrode and seeding layer; and a ZrO2 film was deposited as a buffer layer between the LNO film and the Si substrate. X-Ray Diffraction (XRD), and Scanning Electronic Microscopy (SEM) were used to examine the structure, orientation, and morphology of the PZN-xPT thin films. The dielectric and ferroelectric properties of the films were measured with an impedance analyzer and a standard ferroelectric testing system, respectively. The results showed that perovskite structure with (100) orientation was successfully obtained in the PZN-xPT films. The film exhibited a typical ferroelectric P-E hysteresis loop with a high remanent polarization.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125210388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-09-01DOI: 10.1142/S1465876303001940
J. Chiou, Y. J. Lin
In this paper, we have successfully modeling a vertical motion electrostaitc comb drive and proof it's efficiency by using existed experimental data. A commercial 3-D MEMS Simulator was employed to stimulate the static levitation of vertical comb drive. Note that, by gradually increasing the dc bias voltage, each simulation process is either converged slowly or even enters the divergence stage. Hence, the 3-D simulator is degraded in simulating vertical electrostatic comb drive in full input range. In the present modelling method, Maxwell 2-D solver was employed to calculate the comb finger capacitance at different z positions firstly. Second, A 6th-order curve fitting was used to extract the capacitance function, C(z), and the unit electrostastic force function, dC/dz, was obtained by taking derivative of capacitance function. Finally, a dynamic system model block diagram was established in Matlab Simulink program environment. A set of ideal geometry parameter was selected to verify the accuracy of our m...
{"title":"A New Modeling Method Of Vertical Electrostatic Comb Drive","authors":"J. Chiou, Y. J. Lin","doi":"10.1142/S1465876303001940","DOIUrl":"https://doi.org/10.1142/S1465876303001940","url":null,"abstract":"In this paper, we have successfully modeling a vertical motion electrostaitc comb drive and proof it's efficiency by using existed experimental data. A commercial 3-D MEMS Simulator was employed to stimulate the static levitation of vertical comb drive. Note that, by gradually increasing the dc bias voltage, each simulation process is either converged slowly or even enters the divergence stage. Hence, the 3-D simulator is degraded in simulating vertical electrostatic comb drive in full input range. In the present modelling method, Maxwell 2-D solver was employed to calculate the comb finger capacitance at different z positions firstly. Second, A 6th-order curve fitting was used to extract the capacitance function, C(z), and the unit electrostastic force function, dC/dz, was obtained by taking derivative of capacitance function. Finally, a dynamic system model block diagram was established in Matlab Simulink program environment. A set of ideal geometry parameter was selected to verify the accuracy of our m...","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127127270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-09-01DOI: 10.1142/S1465876303002015
D. Sheeja, B. Tay, L. J. Yu, J. Miao, Y. Fu, D. Chua, W. Milne
The amorphous carbon films prepared by filtered cathodic vacuum arc (FCVA) deposition system are superior in nature with very smooth surface morphology, relatively high hardness, favorable tribological behaviour and excellent bio-compatibility. These exceptional qualities make them suitable for many device applications. However, the superior quality films prepared at relatively lower substrate bias such as -80V exhibits high compressive stress and thus limit the thickness of the film. This constraint is overcome by stress reduction, which is achieved by preparing the film in conjunction with high substrate pulse biasing. Free-standing Diamond-like Carbon (DLC) micro-cantiliver arrays were successfully fabricated by a single photolithography step. The relatively thick (~1μm), smooth (Rms ~0.75nm), low stress ( substrates, by the FCVA deposition system in conjunction with high substrate pulse biasing of -5kV, 900Hz and 30μs. The undecutting of the microstructure was carried out by anisotropic wet etching of Si in 40 wrt% KOH at 23°C for 31 hrs. The SEM image of the free-standing DLC micro-cantiliver arrays reveals that the maximum transverse deflection of the cantilever at the free end is quite low. The quantitative measurements of deflections were also carried out using an optical profiler to verify.
{"title":"Fabrication Of Smooth Diamond-Like Carbon Microcantilever Arrays","authors":"D. Sheeja, B. Tay, L. J. Yu, J. Miao, Y. Fu, D. Chua, W. Milne","doi":"10.1142/S1465876303002015","DOIUrl":"https://doi.org/10.1142/S1465876303002015","url":null,"abstract":"The amorphous carbon films prepared by filtered cathodic vacuum arc (FCVA) deposition system are superior in nature with very smooth surface morphology, relatively high hardness, favorable tribological behaviour and excellent bio-compatibility. These exceptional qualities make them suitable for many device applications. However, the superior quality films prepared at relatively lower substrate bias such as -80V exhibits high compressive stress and thus limit the thickness of the film. This constraint is overcome by stress reduction, which is achieved by preparing the film in conjunction with high substrate pulse biasing. Free-standing Diamond-like Carbon (DLC) micro-cantiliver arrays were successfully fabricated by a single photolithography step. The relatively thick (~1μm), smooth (Rms ~0.75nm), low stress ( substrates, by the FCVA deposition system in conjunction with high substrate pulse biasing of -5kV, 900Hz and 30μs. The undecutting of the microstructure was carried out by anisotropic wet etching of Si in 40 wrt% KOH at 23°C for 31 hrs. The SEM image of the free-standing DLC micro-cantiliver arrays reveals that the maximum transverse deflection of the cantilever at the free end is quite low. The quantitative measurements of deflections were also carried out using an optical profiler to verify.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"54 65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124706568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-09-01DOI: 10.1142/S1465876303001757
Ching Lian Chua, F. Chollet, Jie He
The Mimosa Pudica is an action plant that closes its leaves when given a stimulus. The plant integrates both sensing and actuating mechanisms, and the distinctive motion is about a hinge-like point, the pulvinus, making the characterization of the motion attractive. In this project, experiments were set up to measure the characteristics of the plants in the goal to estimate the possibility to produce micro-actuator based on a similar principle. The signal speed, the sensitivity, the actuator speed, the power, the torque produced by the plant were measured by using different sensors. The results showed that the torque is dependent on the diameter of the pulvinus and that actuator could reach a top angular velocity of 1 rad/s. We developed a phenomenological model to describe the behavior of the plant that could match experimental results and propose an original physical description of the mechanism inside the plant by considering a phase transition behavior instead of the classical ion channel model. Finally, the plant actuator energy density is also compared with other known micro-actuators and the possibility to use the plant as a micro-actuator is discussed.
{"title":"Study Of A Biological Actuator And Sensor: The Mimosa Pudica","authors":"Ching Lian Chua, F. Chollet, Jie He","doi":"10.1142/S1465876303001757","DOIUrl":"https://doi.org/10.1142/S1465876303001757","url":null,"abstract":"The Mimosa Pudica is an action plant that closes its leaves when given a stimulus. The plant integrates both sensing and actuating mechanisms, and the distinctive motion is about a hinge-like point, the pulvinus, making the characterization of the motion attractive. In this project, experiments were set up to measure the characteristics of the plants in the goal to estimate the possibility to produce micro-actuator based on a similar principle. The signal speed, the sensitivity, the actuator speed, the power, the torque produced by the plant were measured by using different sensors. The results showed that the torque is dependent on the diameter of the pulvinus and that actuator could reach a top angular velocity of 1 rad/s. We developed a phenomenological model to describe the behavior of the plant that could match experimental results and propose an original physical description of the mechanism inside the plant by considering a phase transition behavior instead of the classical ion channel model. Finally, the plant actuator energy density is also compared with other known micro-actuators and the possibility to use the plant as a micro-actuator is discussed.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"252 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114289175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-09-01DOI: 10.1142/S1465876303002076
J. Sheu, Cheng C. Chen, S. P. Yeh, H. Chou
Convex and concave nano-pyramid Arrays (NPAs) with an areal bit density of 258 Gbits/in2 has been demonstrated by means of scanning probe lithography (SPL) and wet ecthing on the (100) silicon wafer. We investigated the use of a contact-mode atomic force microscope (AFM) in the generation of oxide patterns on silicon (100) surfaces. Subsequently, utilizing oxide patterns as Si etching masks, the Si substrate was dipped in aqueous KOH solution, where un-oxidized regions are selectively etched by aqueous KOH orientation-dependent etching (ODE). Using this simple process, 20nm convex NPAs with 100nm pitch can be fabricated successfully. Similarly, about 2nm concave NPAs with 100nm were obtained after the oxidized samples were dipped in acqueous HF solution, the oxide regions were selectively etched away. To demonstarte the capability of this technology, the ascii codes were written on silicon and the data storage density more than 10 times of current optical recording has been achieved. We also demonstrated that the minimum size of the pyramids and the minimum pitch could be easily controlled by the apex size of the pyramid, that is, the size of the oxidized region by AFM-based field-induced oxidation. The results indicated that this technique has potentials to provide a pathway to the higher densities that will be needed in the decades ahead.
{"title":"Fabrication Of Ultrahigh-Density Nano-Pyramid Arrays (Npas) On (100) Silicon Wafer Using Scanning Probe Lithography And Anisotropic Wet Etching","authors":"J. Sheu, Cheng C. Chen, S. P. Yeh, H. Chou","doi":"10.1142/S1465876303002076","DOIUrl":"https://doi.org/10.1142/S1465876303002076","url":null,"abstract":"Convex and concave nano-pyramid Arrays (NPAs) with an areal bit density of 258 Gbits/in2 has been demonstrated by means of scanning probe lithography (SPL) and wet ecthing on the (100) silicon wafer. We investigated the use of a contact-mode atomic force microscope (AFM) in the generation of oxide patterns on silicon (100) surfaces. Subsequently, utilizing oxide patterns as Si etching masks, the Si substrate was dipped in aqueous KOH solution, where un-oxidized regions are selectively etched by aqueous KOH orientation-dependent etching (ODE). Using this simple process, 20nm convex NPAs with 100nm pitch can be fabricated successfully. Similarly, about 2nm concave NPAs with 100nm were obtained after the oxidized samples were dipped in acqueous HF solution, the oxide regions were selectively etched away. To demonstarte the capability of this technology, the ascii codes were written on silicon and the data storage density more than 10 times of current optical recording has been achieved. We also demonstrated that the minimum size of the pyramids and the minimum pitch could be easily controlled by the apex size of the pyramid, that is, the size of the oxidized region by AFM-based field-induced oxidation. The results indicated that this technique has potentials to provide a pathway to the higher densities that will be needed in the decades ahead.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128240216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-09-01DOI: 10.1142/S146587630300199X
Y. T. Wong, M. Manimaran, F. Tay
Synthesis of alkanethiolated gold nanoparticles, which formed spontaneous ordering of larger nanoclusters, has been successfully demonstrated. These three-dimensional nanoclucters containing thousands of gold nanoparticles functionalized with 1, 6-hexanedithiol have interesting properties, which were characterized using High Resolution-Transmission Electron Microscopy (HR-TEM) coupled with Energy Dispersive Spectrometry, Scanning Electron Microscopy and X-ray Photon Spectroscopy (XPS). These results are valuable for further exploration into the nanoclusters' electronic characteristics as well as to understand the thiol chemisorption and physisorption processes onto various substrates such as glass and silicon.
{"title":"Synthesis And Characterisation Of Alkanethiolated Nanogold Clusters For Biomems Applications","authors":"Y. T. Wong, M. Manimaran, F. Tay","doi":"10.1142/S146587630300199X","DOIUrl":"https://doi.org/10.1142/S146587630300199X","url":null,"abstract":"Synthesis of alkanethiolated gold nanoparticles, which formed spontaneous ordering of larger nanoclusters, has been successfully demonstrated. These three-dimensional nanoclucters containing thousands of gold nanoparticles functionalized with 1, 6-hexanedithiol have interesting properties, which were characterized using High Resolution-Transmission Electron Microscopy (HR-TEM) coupled with Energy Dispersive Spectrometry, Scanning Electron Microscopy and X-ray Photon Spectroscopy (XPS). These results are valuable for further exploration into the nanoclusters' electronic characteristics as well as to understand the thiol chemisorption and physisorption processes onto various substrates such as glass and silicon.","PeriodicalId":331001,"journal":{"name":"Int. J. Comput. Eng. Sci.","volume":"114 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123948383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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