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This paper presents a method for optimizing the performance of a real-time, long term, and accurate accelerometer based displacement measurement technique, with no physical reference point. The technique was applied in a system for measuring machine frame displacement. The optimizer has three objectives with the aim to minimize phase delay, gain error and sensor noise. A multi-objective genetic algorithm was used to find Pareto optimal estimator parameters. The estimator is a combination of a high pass filter and a double integrator. In order to reduce the gain and phase errors two approaches have been used: zero placement and pole-zero placement. These approaches were analysed based on noise measurement at 0g-motion and compared. Only the pole-zero placement approach met the requirements for phase delay, gain error, and sensor noise. Two validation experiments were carried out with a Pareto optimal estimator. First, long term measurements at 0g-motion with the experimental setup were carried out, which showed displacement error of 27.6 ± 2.3 nm. Second, comparisons between the estimated and laser interferometer displacement measurements of the vibrating frame were conducted. The results showed a discrepancy lower than 2 dB at the required bandwidth.

Diamond tools play a critical role in ultra-precision machining due to their excellent physical and mechanical material properties, such as that cutting edge can be sharpened to nanoscale accuracy. However, abrasive chemical reactions between diamond and non-diamond-machinable metal elements, including Fe, Cr, Ti, Ni, etc, can cause excessive tool wear in diamond cutting of such metals and most of their alloys. This paper reviews the latest achievements in the chemical wear and wear suppression methods for diamond tools in cutting of ferrous metals. The focus will be on the wear mechanism of diamond tools, and the typical wear reduction methods for diamond cutting of ferrous metals, including ultrasonic vibration cutting, cryogenic cutting, surface nitridation and plasma assisted cutting, etc. Relevant commercially available devices are introduced as well. Furthermore, future research trends in diamond tool wear suppression are discussed and examined.

Figure S4. HIF activation by hypoxic and mimetic culture. A. Western blot was first labelled for HIF (Left), then washed and re-blotted for Tubulin (right). This unedited western shows MCF7 and MDA-MB-231 parental cells cultured in 21% and 1% oxygen for 48 hours before lysis. B. Western blot was cut at approximately 80kDa and the top was labelled for HIF1 whilst the bottom was labelled for Tubulin. This unedited western shows MCF7 and MDA-MB-231 parental cells exposed to varying concentrations of CoCl2. (PPTX 1037Â kb).

We discuss the creation of an Integrated Knowledge Centre, a unique collaboration between academia and industry, which is delivering to UK industry 'disruptive' technologies based on ultra precision engineering. The partners include Cranfield University, the University of Cambridge, University College London, and the OpTIC Technium. This paper concentrates on the development of Knowledge Transfer systems and the successful implementation of processes for the delivery of postgraduate taught courses, short courses for industry, and distance learning packages. In order to retain competitive advantage, UK precision engineering industry requires a regular supply of technically proficient and organizationally prepared graduates. This paper explains the approach taken by Cranfield University and its partners to increase the size of the pool of postgraduate precision engineers and to enhance the skills of industrially based engineers. The approach involves the design of a multi-level system, which draws on increased connectivity between the University, UK Engineering companies, and the student. The main vehicle for providing the technical training is the postgraduate Masters degree in "Ultra Precision Technologies". We explain how this course has been designed for broad appeal, whilst incorporating world class technical teaching and an external focus on the needs of participating companies.

The fields of astronomy science have presented significant precision engineering challenges. Numerous solutions for these fields of science have achieved unprecedented levels of accuracy, sensitivity and sheer scale. Notwithstanding of their importance to science understanding, many of these precision engineering developments have become key enabling technologies for wealth generation and other human well-being issues. This paper provides a brief historical overview of astronomy instruments. Later, details of critical precision engineering developments that supported the establishment of leading European astronomical instruments are illustrated. Finally, significant precision engineering demands to enable future sciences programmes are introduced.

Recently established the Helios 1200 (RaptTM ) is a unique facility designed for the figuring of large optical surfaces [1]. It combines a CNC machine tool with a reactive atom plasma (RAP) process. This provides a unique rapid surface figuring capability with tool size and tool path motion flexibility. RAP is a proven technology for processing silicon based optical materials [2]. The aim with this technique is to achieve figuring correction of metre size optical components in 10 hours - a much reduced process time compared to the 100 hours currently needed. This paper focuses on key technical tasks to achieve a cost-effective figuring method using RAP. Classically a figuring process is carried out iteratively by analyzing surface figure error and removing material using an optimum tool path algorithm. In this work, the material removal is achieved by decomposing the compound SF6 in a plasma jet to obtain free fluorine radicals which etch away silicon based material. In this paper, measurements of the specific material removal rate and footprint of the plume over a range of substrate temperatures are presented. Then the authors present a base-line process for the neutral removal of material over a large area. Various tool path algorithms are investigated some of which include time-dwell adaptation based on substrate temperature. Finally, the issue of heat transfer is discussed, and both experimental and finite element analysis results are presented. The processed surfaces are analyzed using coherence probe and phase-shifting interferometers for surface morphology and 3D surface form respectively. Surface roughness (Sq) is reported within the 2-3 nanometre range on fused silica and surface flatness is within the +/-50 nanometre range after 0.5 micrometre deep material neutral removal (Typical processed area: 70x200millimetre).

Roll-to-roll printing on continuous plastic films could enable the production of flexible electronics at high speed and low cost, but the granularity of feature sizes is limited by the system accuracy. Technologies such as gravure printing and nanoimprint lithography demand a level of rotary motion precision that cannot be achieved with rolling element bearings. Manufacturing tolerances of the rotating parts, thermal drift and process forces in combination with structural compliance add up to additional error motions. In this master by research an active magnetic bearing (AMB) solution is designed for a new, super-sized roll-to-roll flexible electronics production machine, which was so far based on hydrostatic bearings. The magnetic bearing could actively compensate the accumulated synchronous error and maintain high accuracy under all conditions. However, the asynchronous error of a conventional AMB with the required size and power is a problem. In order to reduce the relatively high positioning uncertainty of active magnetic bearings an innovative radial position measurement based on linear, incremental encoders with optical conversion principle is proposed. A commercial encoder scanning head faces a round scale with concentric, coplanar lines on its face. By counting these lines the radial position can be measured. Because such a scale is not readily available, it is made by micro-machining. In experiments, different machining methods are compared. Then a magnetic bearing is built to demonstrate the efficacy of the proposed sensor. As a result, the best measurement noise is 3.5nm at 10kHz and a position uncertainty of approximately 0.25µm has been achieved for the magnetic bearing. These promising results are especially interesting for applications with high precision requirements at low speed of rotation.

Achievable cutting distance of a diamond tool during turning is finite and is a limiting factor in the size of component that can be turned. This limit is particularly problematic when attempting to turn brittle materials, such as those used in infra-red optics. Natural diamond tools have been used for this application. However natural diamond introduces problems: the gems can contain possible contamination with a range of impurities and strong residual stresses from formation. Cutting distance is therefore inconsistent when using natural diamond. Industry is keen to increase possible cutting distance and to increase the consistency of cutting distance. One possible solution is synthetic diamond materials. New CVD single crystal synthetic diamonds possess high purity and consistent growth conditions and therefore have the potential to be a superior tool-material that provides longer achievable cutting distance and extremely consistent cutting behaviour. This new material is compared against natural and HPHT synthetic diamonds in machining tests against silicon workpieces in a selection of tool-orientations. Aluminium workpieces are machined with MCC and natural diamond tools to assess the performance of the new material against this commonly diamond turned material. While analysing the results from these cutting trials the failure modes of diamond tools were examined closely, resulting in discovering the existence of two separate failure modes and the development of a new wear-model. Natural diamond tools were carefully tested using a range of techniques hoping to find a root cause of the wide variability seen. FTIR offered a strong clue as to the defect within natural diamond tools that leads to occasional high cutting life.

Metal-bonded wheels have a few advantages over normal grinding wheels, including higher stiffness, better thermal conductivity for removing process heat and high tool durability. This means grinding of hard materials like ceramics can be done more accurately; the tool life is longer; reshaping of the tool is delayed; and higher G-ratios can be achieved. To keep the super-abrasive metal-bonded grinding wheels sharp and to ground mirror-like surfaces, in ELID-grinding the wheels are dressed continuously and in-process through electrolytic passivation. An electric current between the anodic wheel and an external electrode can lead to the formation of an insulating layer covering the wheel. The goal of this study is to investigate the fundamentals in the growth of the layer in order to have a better understanding in the process. By analyzing the evolution of the voltage and current pulses generated by the power supply (Fuji ELIDER ED921) the layer growth can be monitored. At the start of pre-dressing, the cast iron bond (CIB) is purely metallic. The impedance of the electrolytic cell has a high capacitance and a small resistance. The current dissolves the iron which is then recombined with oxidizers of the electrolyte to form dense and insulating hydroxides. Measurements of the passivation layer resistance for different parameter settings show a steady rise until the insulation is completed. The results for different parameter settings are consistent with Faraday‟s law which states that the accumulated charge governs the layer growth. From these experiments an equivalent electrical model is derived. ispartof: pages:225-229 ispartof: Proceedings of the 12th euspen International Conference vol:12 pages:225-229 ispartof: 12th International Conference of the European Society for Precision Engineering & Nanotechnology location:Stockholm date:4 Jun - 8 Jun 2012 status: published