4M Knowledge base - papers

J. Dalin (a), J. Wilde (a), A. Synodinos (b), P. Lazarou (b)and N. Aspragathos (b)

(a) University of Freiburg – IMTEK, Department of Microsystems Engineering, Georges-Köhler Allee 103, 79110, Freiburg, Germany, contact: Johan.Dalin@imtek.uni-freiburg.de
(b) Robotics Group, Department of Mechanical Engineering and Aeronautics, University of Patras, Greece, contact: Lazarou@mech.upatras.gr

Abstract

Self-assembly is relatively unused in industrial micro-fabrication, although it offers opportunities to simplify processes and to lower manufacturing costs. A variety of self-assembly procedures have been introduced that take advantage of various forces, e.g. capillary, gravitational, electro-static. In this paper a concept for the alignment of micro-parts on a substrate using fluidic-self-assembly with electro-static attraction is presented. Further, FEM-simulations for the electro-static alignment force are performed and its dependence on several geometric parameters, e.g. the width of the binding sites and the distance between micro-part and substrate at the binding sites, is investigated. Based on results an analytic model is extracted. Furthermore, simulations are also performed to estimate capillary alignment forces, acting on micro-parts that are self-aligned. Finally, the magnitude of electro-static and capillary forces is compared. This novel assembly concept, where the alignment of the component at the binding site is achieved due to electro-static energy minimisation and, optionally, in combination with capillary alignment, could be beneficial in the manufacturing of heterogeneously integrated MEMS, such as optical and RF micro-systems.

P. Lazarou (a), N.A. Aspragathos (a), E. Jung (b)

(a) Robotics Group, Department of Mechanical Engineering and Aeronautics, University of Patras, Patras T.K. 26500, Greece
(b) Chip Interconnection Technologies, Fraunhofer IZM Berlin, Germany

Abstract

Micromanipulation is a very important issue in several fields of technology (microelectronics, optoelectronics & MEMS device packaging). Current implementations do not provide both sub-micron accuracy and movement of parts over centimeter-scale to a ~100μm final alignment precision. A micropart-inside-a-liquid-droplet manipulation concept that manages to bridge the gap from meso via the micro to the sub-micron scale in a fully contained process has been previously introduced by integrating the phenomena of electrowetting, dielectrophoresis and fluidic self-assembly. In this paper, an investigation of the electric fields that drive the manipulation of the droplet and micropart during the stages of electrowettng and dielectrophoresis is presented. Information for critical factors such as electrostatic force, Maxwell stress and surface charge density distribution is provided. Their effect on the manipulation process is verified, in accordance to theory.

Karl F. Böhringer
Department of Electrical Engineering, University of Washington, Seattle, WA 98195-2500, USA

Abstract

Self-assembly is the autonomous and spontaneous organization of components into patterns or structures. Self-assembly is ubiquitous in nature, e.g. in the growth of crystals and organisms, but also at macroscopic scales – it is nature’s prevalent paradigm for manufacturing. Self-assembly also provides the basis for important new industrial manufacturing techniques, especially for components at the milli, micro, and nano scales: their small sizes and large numbers scale unfavorably for common serial techniques but favorably for a new, massively parallel approach. We believe that self-assembling systems will be able to create complex, heterogeneous, non-periodic, three-dimensional
devices in massively parallel production processes. Hence, our research investigates the scientific and engineering foundations of self-assembly processes for integrated micro/nanoelectromechanical systems (MEMS/NEMS).