4M Knowledge base - papers

T. Rechtenwald (a), A. Kopczynska (b), E. Schmachtenberg (b), M. Devrient (a), T. Frick (a), M. Schmidt (a)

(a) Bayerisches Laserzentrum GmbH, Konrad-Zuse-Str. 2-6, 91052 Erlangen, Germany
(b) Lehrstuhl für Kunststofftechnik, Friedrich-Alexander Universität, Erlangen, Germany

Abstract

Decreasing sales figures and increasing demand of different variants at the same time, as well as the desire of a short time to market pose a challenge for nowadays manufacturing technology. In this context, a new flexible production technology for mechatronical devices, which include also optical functions, called Embedding Stereolithography (eSLA) is introduced. eSLA combines the flexibility to automatically generated inner and outer complex geometries of conventional SLA with embedded functional components, which are conducted by generative manufactured electrical and/or optical structures. To form a rugged mechatronical device out of mechanic and/or electronic parts by eSLA a sufficient wetting of the used components by the processed liquid photopolymer is needed. Therefore the surface tension and viscosity of different photopolymers is measured and compared to surface energies and surface roughness of relevant component materials. Afterwards the characteristics of wetting of the chosen photopolymers on these materials are discussed.

Per Johander(a), Sjoerd Haasl(b), Katrin Persson(b) and Urban Harrysson(c)
a: IVF- Industrial Research and Development Corporation; Argongatan 30, 431 53 Mölndal, Sweden,
b: IMEGO AB; Arvid Hedvalls Backe 4, 411 33 Göteborg, Sweden;
c: FCubic AB; Källarlyckevägen 6, 429 35 Kullavik, Sweden

Abstract

Nearly every microsystem application requires specific packaging solutions. In this paper we suggest a new approach to use layer manufacturing as a generic tool for microsystem integration. Three different methods to produce 3D electrical interconnects are presented. Ink jet printing is used for the ceramic layer manufacturing process, as well as for the printing of silver for circuit patterns. The technique is demonstrated for an Inertial Measurement Unit(IMU) platform. A four-sided pyramid was manufactured with layer manufacturing in ceramics and four gyroscopes were mounted on the sides of the pyramid. A demonstrator with three light diodes was also manufactured to demonstrate the possibility to produce 3D electrical interconnects in the volume of the pyramid.

A. Schneider (a), L. Frasson (b), T. Parittotokkaporn (c), F. M. Rodriguez Y Baena (b), B. L. Davies (b),
and S. E. Huq (a)

(a) Science and Technology Facilities Council, Rutherford Appleton Laboratory, Technology – Central Microstructure Facility, Harwell Science and Innovation Campus, Didcot, OX11 0QX, UK
(b) Mechatronics in Medicine Lab., Depart. of Mechanical Engineering., Imperial College, London, SW7 2AZ, UK
(c) Institute of Biomedical Engineering, B 422 Bessemer Building, Imperial College, London SW7 2AZ, UK

Abstract

The development of a novel biomimetic neurosurgical probe is inspired by nature. Some insects have spines with a unique surface texture which enables them to penetrate tissue more easily. This surface texture consists of cutting teeth and fin-like pockets on the spine. Instead of drilling, the insect slides its spine into the fibre through the reciprocating motion of independent segments. Applying the same or similar microtexture to a miniaturized neurosurgical endoscope could improve existing tools for brain surgery and brain biopsy. The development of such endoscope could minimize the damage caused by inserting the probe whilst avoiding the risk of buckling, which is a common occurrence when thin flexible probes are axially loaded.
To replicate the surface microtexture, teeth and fin-like high-aspect-ratio microstructures were fabricated. Different geometries of these fins and teeth were studied for insertion into tissue so that the texture could be characterized for friction and tribological interaction with tissue. For these tests, free-standing long and narrow strips with microstructures in up to 525 μm thick SU-8 were designed, fabricated, and mounted onto prototypes made by
stereolithography. This paper focuses on the fabrication of the microtextured strips. The required geometry of these
strips can cause considerable bending. The structures were investigated regarding fabrication and stress conditions.