4M Knowledge base - papers

Critical Analysis of an Existing Calibration Procedure Built in a White Light Interferometer Microscope and Proposal of an Alternative Spline-Based Approach

C. Ferri, E. Brousseau
Manufacturing Engineering Centre, Cardiff University, CF24 3AA, UK

Abstract

This paper presents a spline-based calibration method in order to overcome the limitations observed in the built – in calibration procedure of a commercial white light interferometer microscope. Quantitative experimental evidence highlighted the presence of inconsistencies of this built-in procedure with the international standard about the linear calibration method. A bias in the measurement results was shown experimentally. The proposed spline-based approach was implemented with reference materials of nominal heights ranging from 182 to 218 μm. The state of control of the measuring process during a calibration and between calibrations was also monitored using purpose developed control chart designs.

Submitted on November 12, 2007 - 16:23.

Demouldability of Microstructures in Polymer Moulding

A De Grave, T. Eriksson, H.N. Hansen
Department of Manufacturing Engineering and Management, Technical University of Denmark, 2800 Kgs., Lyngby, Denmark

Abstract

Demoulding micro structured surfaces and micro parts is an important issue in replication of micro technology based components. In this paper a state of the art on ways to improve demoulding of microstructured parts both in polymer moudling and metal injection moulding is presented. The approach is described and simulation methods are shown in relation to previously existing studies. The approach chosen is the investigation of the influence of the demoulding angle on the demouldability of polymer mouldings. The design is based on a number of micro sized cones with different slope angle placed on a flat metal surface. A mould design is proposed and simulated. The design is based on a number of micro sized cones with different slope angle placed on a flat metal surface. A method for characterization of the mould using Laser Scanning Confocal Microscopy (LSCM) and Atomic Force Microscopy (AFM) to verify the slope angle and the straightness quality of the slope is discussed. Initial mould filling simulations using a 2½ D mesh show that a real 3D simulation were performed.

Submitted on November 12, 2007 - 16:23.

categories

polymers | Replication

Design and Optimization of Flat Solenoid MEMS Actuator by Selection of Proper Material Properties

G. Todorov, K. Kamberov, and L. Dimitrov
CAD/CAM/CAE Laboratory, Technical University of Sofia, Sofia 1000, Bulgaria

Abstract

MEMS actuators are widely used in modern industry. Their main advantage is the concentration of desired mechanical characteristics in a limited space. This paper presents a design and optimization of a flat solid MEMS actuator. The optimization is based of the selection of material properties needed for the achievement of the actuator mechanical characteristics required for good performance. The main goal is to reach necessary output mechanical force with minimal side force effects. The output mechanical force is evaluated by modeling and simulation of the magnetic field and its parameters by the use of FE Analyses. In order to make proper simulations, a finite element model of the complete actuator structure is made up suggested).

Another problem that has been solved in the paper is checking of actuator’s geometry and its dimensions in order to evaluate the effective use of the material. As a result of the study, the optimal output function of the mechanical force versus the stage position has been determined. This has been done on the basis of updated material specifications. The optimal design of a flat solenoid MEMS actuator is proposed.

Submitted on November 12, 2007 - 16:23.

Design for Microassembly – Capturing Process Characteristics

C. Tietje(a), S. Ratchev(a)(b)
a: Precision Manufacturing Group, The University of Nottingham, Nottingham NG7 2RD, UK
b: Centre of Excellence in Customised Assembly, The University of Nottingham, Nottingham NG7 2RD, UK

Abstract

Micro systems technology (MST) is considered to be an enormously strong economic driver in the 21st century. Market estimations predict a large volume of products in MST within the next decade. Within MST, microassembly shows vast potential in a wide range of industrial applications. Currently this potential has only been shown by the development of demonstrator products within research environments and with limited transfer to industrial practice. Microassembly is in particular necessary to produce multi-material devices with complex and true three-dimensional geometries. Although there are various DFA methods in use since the seventies to guide the designer to producing efficient and economic design, there is a lack of well defined solutions tailored to the microworld and its specific challenges. In fact, most DFA methods focus on assembly of products with part dimensions ranging from a few millimetres up to several decimetres. For the design of microproducts it is essential to consider key assembly process features in the early design stages. Furthermore it is important to provide support in the selection of suitable assembly processes by considering process related requirements as well as offering quantitative cost analysis to support the decision making to assure best producability and by this means enable an increased transfer of microproducts from the research laboratory to industrial production.

Submitted on November 12, 2007 - 16:23.

Design of a Micro Injection Moulding Machine for Thermosetting Moulding Materials

W. Michaeli, T. Kamps
Institute of Plastics Processing at RWTH Aachen University, 52056 Aachen, Germany
A De Grave, T. Eriksson, H.N. Hansen
Department of Manufacturing Engineering and Management, Technical University of Denmark, 2800 Kgs., Lyngby, Denmark

Abstract

Demoulding micro structured surfaces and micro parts is an important issue in replication of micro technology based components. In this paper a state of the art on ways to improve demoulding of microstructured parts both in polymer moudling and metal injection moulding is presented. The approach is described and simulation methods are shown in relation to previously existing studies. The approach chosen is the investigation of the influence of the demoulding angle on the demouldability of polymer mouldings. The design is based on a number of micro sized cones with different slope angle placed on a flat metal surface. A mould design is proposed and simulated. The design is based on a number of micro sized cones with different slope angle placed on a flat metal surface. A method for characterization of the mould using Laser Scanning Confocal Microscopy (LSCM) and Atomic Force Microscopy (AFM) to verify the slope angle and the straightness quality of the slope is discussed. Initial mould filling simulations using a 2½ D mesh show that a real 3D simulation were performed.

Micro products made of thermosetting polymers enable innovative applications since thermoplastics do not always yield the desired properties: thermosetting moulding grades offer advantages in thermal durability and chemical resistance in comparison to thermoplastic resins. Processing smallest quantities of polymeric material for applications in micro system technology require high process accuracies, e.g. in the volume of plasticised material and injection dynamics. Alternative machine concepts especially designed for micro injection moulding meet these requirements by means of special constructive setups mostly by using a plunger for injection. An appropriate micro injection moulding machine prototype is available at IKV Aachen. A new design of the plasticising and injection unit specially designed for thermosetting moulding materials is presented in this paper.

Submitted on November 12, 2007 - 16:23.

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