| PID189549 |
Mechanistic Modelling of the Micro- End Milling OperationL. Uriarte a, S. Azcarate a, A. Herrero a, L.N. Lopez de Lacalle b , A. Lamikizb AbstractThe paper describes a mechanistic model to predict the micro--milling cutting forces and to estimate the tool deflection and the real tool-path during the micro--milling process. Beginning from the “conventional” end milling cutting force model, several modifications are proposed to adapt it for the prediction of the micro--milling cutting forces, which is the aim of this research. A variety of end mill shapes are considered in the geometric part of the model. The paper presents the experimental validation using two-flute carbide micro-- end-mills with diameters from 0.1 to 0.4 mm. Finally, the consistency between the simulated and measured cutting force is shown as main conclusion. Keywords: Micro--milling, Modelling |
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| PID189823 | On Forces and Interactions at Small Distances in Micro and Nano Assembly Process D. Dantchev, K. Kostadinov Institute of Mechanics, Bulgarian Academy of Sciences, Acad. G. Bonchev St. Bl. 4, 1113 Sofia, Bulgaria AbstractWe present a short review on the quantum and the thermodynamic Casimir effect and show its practical relevance when considering objects placed away from each other at a distance below a micrometer range. Emphasis is made on the existing experimental verifications of the available theory as well as on the unresolved problems of the theory and the experiment. Everywhere where possible we try to point the potential practical application of the results described not only restricted to micro and nano assembly. Keywords: Casimir effect, micro & nano assembly, gripping force, micro fluidic interaction |
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| PID190020 |
Design procedure of planar compliant microgrippers with flexural jointsF. Székely, T. Szalay AbstractThe overall design scope of most microgrippers developed in recent years lacks a systematic mechanism design approach. Accordingly, the main objective of this investigation is to establish a new design concept in order to enhance the design scope of microgrippers. Using a systematic design procedure which particularly stresses planar compliant mechanisms, this study presents a two-fingered microgripper which has parallelogram mechanism. By the help of this construction the gripping surfaces stay in parallel position during its motion. The preliminary Finite Element (FEM) simulation results are in good agreement with the expected kinematic motion. Moreover, the stress analysis also points out that the relationship between the direction of driving force and orientation of deflected compliant joints is one of the crucial factors for designing the compliant microgripper mechanism. Hence, the mechanism design concept presented in this study can be integrated e.g. into the design of micro-scale actuating devices for Micro-Electro-Mechanical Systems (MEMS). Keywords: microgripper, compliant mechanism, laser cutting | |
| PID190054 |
Finite element analysis of the micro glass moulding processC. Brecher, M. Winterschladen, S. Lange, F. Klocke, G. Pongs, F. Wang AbstractThe manufacturing of optics is an important field of technology and will serve key-markets in the future. The research activities of the Transregional Collaborative Research Centre ”Process Chains for the Replication of Complex Optical Elements” SFB/TR4 of the Universities of Aachen, Bremen and Stillwater (USA) have the objective to lay the scientific foundations for a deterministic and economic mass production of optical and micro optical components with complex geometries, e.g. aspheric, non-rotational asymmetric or microstructured surfaces eventually superimposed on freeform geometries. The paper presents first principle simulation results of precision glass moulding for the analysis of micro form as well as nano surface quality manufacturing effects during the moulding process. Keywords: Finite Element Analysis, Glass Moulding, Precision Optics |
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| PID190231 |
Unified Approach For Functional Task Formulation In Domain Of Micro/Nano Handling Operations.K. Kostadinova, R. Kasperb, T. Tiankova, M. Al-Wahabb, D. Chakarova, D. Gotsevaa,c AbstractA unified approach for functional task formulation is developed that allows communication between user and team of mechatronic engineers developing the mechatronic handling devices for requested task function. All-important parameters are set for realization of mechanics and control of desired process for automation. 3D variants are modeled in SDS 2004+ and simulated, making interactive closed loop with the user and better communication between different research and industrial domains for achievement of good results. The possibilities of the developed iterative program for the task function formulation are illustrated with the results obtained for the case of micro/nano manipulations necessary for measurement of electrochemical impedance. Keywords: task formulation approach, interactive program, micro/nano handling operations. |
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| PID204355 |
Thermally induced stresses in an adhesively bonded multilayer structure with 30-micron thick film piezoelectric ceramic and metal componentsR.Jourdain and S.A.Wilson Abstract:In this study, the thermal stresses acting in a multilayer structure built up by successive bonding and machining processes are investigated. These arise mainly from the bonding process itself due to the wide mismatch in the coefficients of thermal expansion for the ceramic and metal components. Subsequent machining of the bonded ceramic down to 30 microns thickness leads to a redistribution of the internal stress which must be monitored closely as it influences both the structural integrity and the overall performance of the finished piezoelectric device. Previously reported analytical models are compared to new numerical simulations using either shell elements or two dimensional elements. High aspect-ratio, symmetric and non-symmetric structures are studied to show the changes in stress throughout the fabrication process. The finite element models allow detailed investigation of the stresses in all of the component parts and in the bonding layers. The influence of bond thickness is investigated in the range 0.5 to 10μm. This work shows that even at low bonding temperature the adhesive layer is under quite severe stress. This can be tuned by increasing the bond thickness to achieve high structural integrity and moreover the ceramic is engineered into compressive pre-stress suitable for high performance micro-actuators. Keywords: Bimorph; PZT; actuator; adhesive bonding; micro-fabrication; FEA; ultra-precision grinding, MEMS |
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| PID210079 |
Modelling and simulation of piezoelectric actuation and reliability of micropumpsMeiling Zhu a,*, Paul B. Kirby a, Martin Richter b, Yucel Congar b, Alexander Diehl c, Ralf Voelkl c AbstractModelling and simulation of a low cost micropump with promising mass production is described in this paper. The micropump has a very simple structure and therefore is very low cost effective. The pump consists of one plastic body, one metal diaphragm and three piezo PZT ceramics. The PZT ceramics glued on the metal diaphragm form three actuators and so the metal diaphragm bonded with the plastic body constitute three chambers, which are connected by interconnection channel in the plastic body. A 3D finite element analysis (FEA) model including an electromechanical coupled field simulation is set up and static analyses are preceded for different configuration under different applied voltage for understanding and optimization of the micropump performance. A significant dimensional design of piezo PZT actuators is obtained from simulation results. The ratio of the thicknesses of the piezo PZT ceramics to the metal diaphragm and the piezo in-plane dimension are suggested for obtaining a higher stroke for maximizing the pumping effect and lowering maximum stress in the metal diaphragm for concerning reliability issue. Keywords: Micropump; FEA; Piezoelectric actuators; Metal diaphragm |