http://nova.newcastle.edu.au/vital/access/services/Feed ${session.getAttribute("locale")} 5 http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:8695 Flexure hinges are commonly used in many applications which require precise and smooth motions in the nanometer scale. There were various formulations derived using different methods to calculate the stiffness of circular flexure hinges. This article compares these equations with FEA predictions. The limitation of these equations at different t/R (R is the radius and t is the neck thickness) ratios are revealed. Based on the limitations of these design equations, a guideline to select the most accurate equations for hinge design calculations is presented. In addition to the review and comparisons, general empirical stiffness equations in the x- and y-direction were formulated in this study (with errors less than 3% when compared to FEA simulations) for a wide range of t/R ratios (0.05 les t/R les 0.8). 2013-03-28T01:30:31.165Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:7601 New possible nanotechnology applications of some original developments and results of studying the regularities and micromechanisms (physics) of the hydrogen fluoride gas activator influence on oxidation of titanium, zirconium and zirconium-based alloys with niobium, and also - on nitriding, boriding and carbiding a series of refractory metals (Ti, Zr, Nb, Mo, W, Ta) are elaborated. The new possible nanotechnology applications of the techniques and physics of creating a compound-like nanosegregation or the liquid-like nanosegregation at grain boundaries in nanostructured metals, i.e. creating of specific cellular type natural nanocomposites, are considered as well. 2011-04-21T02:50:09.229Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2599 The nine regular papers and five brief papers in this special issue focus on dynamics and control of micro- and nanoscale systems. A brief overview of the issue is provided. 2010-04-27T06:46:35.160Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2596 Nanotechnology is the science of understanding matter and the control of matter at dimensions of 100 nm or less. Encompassing nanoscale science, engineering, and technology, nanotechnology involves imaging, measuring, modeling, and manipulation of matter at this level of precision. An important aspect of research in nanotechnology involves precision control and manipulation of devices and materials at a nanoscale, i.e., nanopositioning. Nanopositioners are precision mechatronic systems designed to move objects over a small range with a resolution down to a fraction of an atomic diameter. The desired attributes of a nanopositioner are extremely high resolution, accuracy, stability, and fast response. The key to successful nanopositioning is accurate position sensing and feedback control of the motion. This paper presents an overview of nanopositioning technologies and devices emphasizing the key role of advanced control techniques in improving precision, accuracy, and speed of operation of these systems. 2010-04-27T06:46:34.989Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:1229 A detailed atomic-resolution scanning tunneling microscopy (STM) and density functional theory study of the adsorption, dissociation, and surface diffusion of phosphine (PH₃) on Si(001) is presented. Adsorbate coverages from ∼0.01 monolayer to saturation are investigated, and adsorption is performed at room temperature and 120 K. It is shown that PH₃ dissociates upon adsorption to Si(001) at room temperature to produce both PH₂ + H and PH + 2H. These appear in atomic-resolution STM images as features asymmetric-about and centered-upon the dimer rows, respectively. The ratio of PH₂ to PH is a function of both dose rate and temperature, and the dissociation of PH₂ to PH occurs on a time scale of minutes at room temperature. Time-resolved in situ STM observations of these adsorbates show the surface diffusion of PH₂ adsorbates (mediated by its lone pair electrons) and the dissociation of PH₂ to PH. The surface diffusion of PH₂ results in the formation of hemihydride dimers on low-dosed Si(001) surfaces and the ordering of PH molecules along dimer rows at saturation coverages. The observations presented here have important implications for the fabrication of atomic-scale P dopant structures in Si, and the methodology is applicable to other emerging areas of nanotechnology, such as molecular electronics, where unambiguous molecular identification using STM is necessary. 2010-04-27T06:38:52.620Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:3285 Cantilevers with single micro- or nanoparticle probes have been widely used for atomic force microscopy surface force measurements and apertureless scanning near-field optical microscopy applications. In this article, I critically review the particle attachment and modification techniques currently available, to help researchers choose the appropriate techniques for specific applications. 2010-04-27T05:07:37.496Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:6025 A piezoelectric tube is shown to have linear, but non-minimum phase dynamics. The main impediment to the actuation of this piezoelectric tube is the presence of a low-frequency resonant mode which causes mechanical vibrations. A physical-model-based control method is extended to non-minimum phase systems in general and successfully applied to damp the resonant mode; leading to a vibration-free actuation of the piezoelectric tube. 2010-04-27T04:31:46.050Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:6028 In the probe-based storage concept being pursued by IBM, a MEMS based micro-scanner is used to position the storage medium relative to the read/write probes. To achieve repeatable positioning over a large storage area, it is necessary to have medium-derived position information. Dedicated servo-fields are typically employed to obtain medium-derived position information. Sub-nanometer positioning resolutions are desirable while writing these servo-fields. Such precise positioning at acceptable bandwidth using a global position sensor requires the directed design of the closed-loop noise sensitivity transfer function so as to minimize the impact of sensing noise. This paper describes one such control architecture based on resonant controllers where the impact of measurement noise on positioning is minimal while providing sufficient damping and hence satisfactory tracking performance. It is estimated that the positioning error due to sensing noise is a remarkably low 0.25 nm. Experimental results are also presented that show error-free operation of the device at high densities. 2010-04-27T04:31:37.511Z ]]>