Researchers: Jarmo Hietanen, Virpi Junttila, and Kimmo Kaski
This research is a combination of two projects: "Modeling and applications of the micromechanical systems in acoustics" and "MEMS simulations", both financed by the Academy of Finland.
The scope of this research is MEMS related fluid-structure interaction, and its core consists of the coupling between the mechanical structure and fluid, more exactly gas, at audio frequencies. Here attention is paid on velocity field produced by moving structures, see figure 34. The need to study internal flow field of microelectromechanical systems is related to internal energy consumption of the device. With non-optimized design, for instance, vortexes can be produced. If this can be avoided with more optimized design, the transducer will achieve higher performance.
|Figure 34: Velocity fields of fluid flow at the tip of a vibrating cantilever structure. On the left: Contours of fluid flow velocity values (blue: low velocity; green: medium velocity; red: high velocity). On the right: Vector field of corresponding velocities.|
Supporting measurement methods, devices, and systems have also been studied in collaboration with several national and international partners. Sample fabrication was made in MESA Research Institute at University of Twente, The Netherlands. Measurement co-operation took place with Microelectronics Center at Technical University of Denmark, Denmark, Institute for Electroacoustics at Darmstadt University of technology, Germany, and Physics Department at Helsinki University, Finland. We have also had simulation collaboration with Laboratory of Applied Mechanics at University of Twente, The Netherlands, and Center for Scientific Computing, Finland. Industry was present in confidential discussion seminars in which the research was shared with Nokia Research Center, Vaisala Oyj, VTI Hamlin, and VTT Electronics.