Research Group Microsystems Simulation

The working group for microsystem simulation was founded in April 2017. Their research interests are the multi-physical modeling of micro- and mechatronic systems as well as their simulation on system level. Mathematical methods of model and reduction and topology optimization are applied.

Research interests

  • Modeling and simulation techniques for multi-physical micro-mechatronic systems
  • Model or reduction for time-efficient system simulation
  • Topology optimization

Due to its nature as an energy converter, the coupling of multiple energy domains is an inherent feature of many microsystems. Their modeling at the continuum level and the numerical simulation of individual components is regarded as state of the art. However, as soon as a co-operation of the component with the surrounding electronics, the housing or other components is to be considered, more compact models with acceptable accuracy are necessary.

A reduced model is obtained by mathematical reduction of the number of degrees of freedom of a numerical model. The main advantage of a mathematical model or reduction (MOR) is its automatability and high accuracy. Our MOR methods can be applied directly to large differential equations systems, which arise, for example, in the Finite Element Method (FEM). Reduced multiphysical models can be solved in a time-efficient manner and can be used as a part of an optimization.


Incoming DFG Project

Jade Welt: Jade Hochschule entwickelt mikrotechnische Systeme weiter

Kick and Catch - cooperative microactuators for freely moving platforms

The aim of this research proposal Kick and Catch is to evaluate concepts and prototypes of microactuators which are not suspended to cantilevers but move freely between several stable end positions. Several kinds of actuators have to cooperate to provide the here proposed sudden displacements. The following state of the art focuses on the fact of freely moving microactuators with fast as well as big displacements, on Model Order Reduction (MOR) of large-scale multiphysics finite element models and on model-based controller design all of which are relevant for Kick and Catch.


Project Groups:

Ulrik Wallrabe, University of Freiburg, Department of Microsystems Engineering, Laboratory for Micoactuators, Georges-Köhler-Allee 102, 79110 Freiburg

Martin Hoffmann, Ruhr-Universität Bochum, Chair for Microsystems Technology, Universitätsstraße 150, 44801 Bochum

Christoph Ament, University of Augsburg, Chair for Control Engineering, Eichleitner Straße 30, D-86159 Augsburg

Tamara Bechtold, Jade University of Applied Sciences, Department of Engineering, Modeling and Simulation of Mechatronic Systems, Friedrich-Paffrath-Straße 101, 26389 Wilhelmshaven


The Bechtold Group for modeling and simulation of mechatronic systems at the Jade University of Applied Sciences aims to develop methodologies for generation of system-level models of Kick and Catch microactuator systems. This work contributes to the work of the Ament group, as an actuator model is essential for control development. Furthermore, the Hoffman and the Wallrabe groups benefit from this work, as the availability of an accurate and efficient model is beneficial in their respective device designs. Furthermore, those methodologies will be applicable to a broad class of cooperative multistable microactuator system models.

The system-level Kick and Catch actuator model will integrate two sub models, the electromagnetic Catch actuator model and the electrostatic respectively piezoelectric Kick actuator model. The micro actuators considered here include nonlinear structural dynamics (with periodic contacts between sphere and platform), electrostatic and magnetic fields for actuation and position sensing. To model these effects with sufficient accuracy, multiphysical numerical models are necessary. Sub models are highly accurate, but too large to be employed within a control loop. Furthermore, the strongly different duration of the kick, spin, fly and catch periods, impose extremely high requirements on modelling the contact events in an adequate way. It is thus the of the Bechtold group to develop suitable methods for order reduction of multiphysical field-solution models and supply those to the Ament group for integration in the control loop. Beyond the present microactuators systems, those methods will be applicable to other multiphysical models, especially under the presence of time-varying contacts and nonlinear effects.


Observer-based control-scheme of the Kick and Catch actuator integrating a system-level model, which consists of a reduced order model (ROM), a lumped element (LE) model or a look-up table (LT) derived from finite element models. The system-level model describes the actuator's behavior in response to voltage and current excitation; in response it provides flying mass' and platform positions. The model supports controller development.


Prof. Dr. -Ing. Ulrike Wallrabe; Prof. Dr. -Ing. Martin Hoffmann; Prof. Dr. -Ing. Christoph Ament; Prof. Dr. -Ing. Tamara Bechtold


Academic Team Members

Chengdong Yuan (Jade2Pro2.0 Ph.D. student), Gunasheela Sadashivaiah (Master student in University of Rostock), Prof.Dr.-Ing. Tamara Bechtold (Jade University of Applied Science), Prof. Dr. Ing. Dennis Hohlfeld (University of Rostock), Siyang Hu (Jade2Pro2.0 Ph.D. student), Sofiane Bouhedma (Ph.D. student in University of Rostock)