4M Knowledge base - papers

Approaching a sub-micron capability index using a Werth Fibre Probe System WFP

Richard Thelen (a), Joachim Schulz (a), Pascal Meyer (a), Volker Sailea (a)
(a) Institute for Microstructure Technology, Research Centre Karlsruhe, 76646 Eggenstein, Germany


Reproducibility and precision of LIGA structures has been claimed in many publications, founded mainly on brilliant pictures. Because of the poor accessibility to the sidewalls many publications are based on surface measurements without including information about z depending aspects [1] and focus on reproducibility as measured close to the top.
Often this neglects operator’s influence, short time and long time reproducibility, environmental effects on the CMM and others. Tactile optical metrology might help to overcome 2D measurements. Repeatability of tactile optical metrology at IMT was proven to be less than 0,3 μm over some months using ultra fine probes with less than 25 μm diameter. In addition DoE was used to determine the minimum deviation for best possible machine settings. Standard Deviation between 50 and 30 nm was measured. Compared to that, uncertainty remains about 1-2 μm for 3D measurements even with z maximum restricted to 1 mm [2]. Not enough to measure sub-μm product variation that is a typical benefit of LIGA products.
Investigations were started at the Research Centre Karlsruhe to find out more about the effects influencing the measurements to explain why repeatability and capability do not match. Interaction between sample and sensor was the main reason. This was simulated and the results were used to reduce the uncertainty of the system. IMT elaborated a new strategy that improves the capability of a coordinate measurement machine CMM with tactile optical sensor for LIGA parts with sub μm variation.

Submitted on July 30, 2008 - 11:48.

ASSEMIC: Research Advances in Microhandling and Assembly – “Special ASSEMIC Session”

Ana Almansa(a), S. Bou(a), Z. Rozynek(a) , W. Brenner(b)
a: Profactor R&S GmbH, Seibersdorf 2444, Austria
b: TU Wien – ISAS, Floragasse 7/2, Vienna 1040, Austria


Few technical fields are so multidisciplinary and present so challenging demands as microtechnologies. The Research and Training Network “Advanced Methods and Tools for Handling and Assembly in Microtechnology” (ASSEMIC) addresses this research field at a European scale. ASSEMIC brings together a consortium of 14 participants, focusing their efforts in microhandling and microassembly. This paper summarizes some of the latest results achieved in this project.

Submitted on November 12, 2007 - 16:23.

Assessment of digital cameras for micro-structural sensing of low contrast surface features

A. Temun, L. Mattsson

Department of Production Engineering, KTH – the Royal Institute of Technology, SE-100 44 Stockholm, Sweden


Evaluation of three digital cameras are presented focusing on their capabilities and applicability in the detection of low-contrast surface features on the micrometer level. The key to a successful identification of surface flaws on micro-structured surfaces, such as silicon wafers is the ability to determine minor deviations in the reflectance of an object surface. Micro-topography of a surface, surface structure and surface roughness has a strong influence on the amount and direction of scattered light. Different portions of the surrounding illumination are reflected on different parts of an uneven surface, hence the resulting contrast-variation on the illuminated surface has a strong correlation to the surface structure itself.

In our work we discuss the possibilities of using either of the investigated cameras for the automated visual inspection of micro-structured surfaces. The cameras - two of them equipped with CCD and one with CMOS image sensors - are studied in an environment which is similar to standard surface appearance measurements, involving human observers. The specimens, featuring different surface structures are imaged in a well-controlled environment under varying illumination conditions. Experimental results of spatial resolution and contrast sensitivity are presented.

Submitted on May 20, 2008 - 11:01.

Automated Patch Clamping Systems Design using Novel Materials

S. Wilson(a)(b), A. Welle(c), E.Gottwald(c), A. Molleman(d), P.B.Kirby(b), W.Pfleging(e), J.J.Ramsden(b), M. Heckele(a)
a: Institute for Microstructure Technology, Forschungszentrum Karlsruhe, 76344 Eggenstein-Leo., Germany
b: School of Applied Sciences., Cranfield University, Cranfield, Beds. MK43 0AL, UK
c: Institute for Biological Interfaces, Forschungszentrum Karlsruhe, 76344 Eggenstein-Leo., Germany
d: School of Life Sciences, University of Hertfordshire, Hatfield, Herts.AL10 9AB, UK
e: Institute for Materials Research 1, Forschungszentrum Karlsruhe, 76344 Eggenstein-Leo., Germany
A. Herrero(a), J. Esmoris(a), S. Azcarate(a), S. Geissdoerfer(b), U. Engel(b)
a: Department of Micro & Nano Technologies, Tekniker, Avda. Otaola 20, 20600 Eibar, Spain
b: Universität Erlangen-Nürnberg, Egerlandstrasse 11, 91058 Erlangen, Germany


The mass production of micro and meso scale products made of polymers or metals is intimately related to the production of high quality microtooling in stable materials capable to provide an accurate and repetitive performance throughout the whole demanded production. As it is widely known, the WEDM process provides high accuracy but is conceptually limited to the production of ruled features. The SEDM process can be a complement to this aspect but the electrodes must be manufactured by other technologies like WEDM, micromilling, turning, etc. Given the importance of several parameters like dimensional accuracy, tooling material for the different replication processes or tooling production technology, the present paper introduces some tests performed by the 4M Metals Workgroup. The analysis of some components manufactured by members of the group is presented discussing the influence of the EDM process on the machined tooling components and the consequent influence on the replication process.

Patch clamping is a highly sensitive technique used to measure the electrical activity of a cell. It is presently a low throughput cumbersome method which requires highly trained and skilled operators to obtain results of value. Patch Clamping is used in applications which include drug screening where there is demand for high throughput systems (HTS). While there are a few commercially available HTS patch clamping systems on the market using traditional patch clamping materials, there are no systems on the market using novel materials, or for dealing with cell networks – a physiologically important consideration for the developing fields of tissue engineering and understanding cell to cell interactions. This paper presents a summary of traditional patch clamping, mentions some commercially available high throughput patch clamping systems based on traditional materials then, using 4M technologies, introduces some novel materials and potential design approaches and processes for producing a polymer based automated patch clamping system.

Submitted on November 12, 2007 - 16:23.

Batch Fabrication Methods for Polymer Based Active Microsystems using Hot Embossing and Transfer Bonding Technologies

T. Grund, M. Heckele and M. Kohl
Forschungszentrum Karlsruhe GmbH, Institute for Microstructure Technology (IMT),Postfach 3640, 76021 Karlsruhe, Germany


A batch compatible process flow to overcome the costly piece by piece assembly of hybrid microsystems is shown. Hot embossing is used to fabricate microstructured polymer layers. Wafer scale compatible bonding tasks are carried out by ultrasonic welding and heat activated bonding with micromachined bonding foils. As demonstrator device, a shape memory alloy (SMA) actuated polymer microvalve is introduced. The valve concept, fabrication technologies and device characteristics are discussed.

Submitted on July 29, 2008 - 11:51.

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