Microsystem simulation

Meisel, I., Ehrhard, P., Simulation of electrically-excited flows in microchannels for mixing applications, in Proceedings of the 5th International Conference on Modeling and Simulation of Microsystems, San )uan, Puerto Rico, 22-25 April 2002, Computational Publications, Boston, pp. 62-65 (2002). 

T. Bechthold, E.B. Rudnyi, and J.G. Korvink. Dynamic electro-thermal simulation of microsystems - a review . Journal of Micromechanics and Microengineering 15 (2005), R17-R31. 

The modeling of a thermopneumatic micropump is given as an example of this approach. Simulation results as well as design aspects of a microsystem containing two of these micropumps are discussed. 

G. Lorenz, R. Neul, Network-type modeling of micromachined sensor systems, Proc. Int. Conf. Modeling and Simulation of Microsystems, Semiconductors, Sensors and Actuators, MSM98, Computational Publications, Cambridge MA, USA, April 1998, 233-238. 

D.P. Kern, Parameter extraction for surface micromachined devices using electrical characterization of sensors, Technical Proceedings of the Fourth International Conference on Modeling and Simulation of Microsystems, Hilton Head Island, South Carolina, Computational Publications, Cambridge, MA, p. 406, 2001. 

One of the most important issues for simulation of microsystems is to know the properties of the materials. In the case of microcantilevers, young modulus, Poisson s ratio, and density are the main parameters to be considered. If monocrystalline silicon is used, as reported in this work, the mechanical properties are well-known (see Table 1). For an anisotropic material such as silicon, the Young s modulus, Poisson s ratio, and shear modulus depend on which crystal direction the material is being stretched. The appropriate values for each direction have to be introduced in the model. 

Figure 4. (A) An image of a microfluidic cell culture chip having 1 mm height difference between the bottom of the chamber and the channels (type 3) (inset An enlargement of a flow equalizer that generates an even lateral distribution of streamlines). (B) A finite element simulation of the vertical flow profile (velocity field) of the system in (A). (Reprinted with permission from Ref [8], copyright 2008 The Chemical and Biological Microsystems Society.)...

Figure 6. Finite element simulation of lateral flow profile (velocity field) of type 3 system with flow equalizers. (Reprinted with permission from Ref [8], copyright 2008 The Chemical and Biological Microsystems Society.)...

Alum NR, White J (1998) A fast integral equation technique for analysis of microflow sensors based on drag force calculations. In Proceedings of the inter-natitmal conference on modeling and simulation of microsystems, semiconductors, sensors and actuators, Santa Clara, pp 283-286... 

Electrokinetic and electrohydrodynamic instability mixing in microsystems is a complex phenomenon which researchers are only beginning to exploit and understand. Future work requires a further development of experimental models and expansion of computational simulations to better understand how the instabilities form and grow. Specific applications of electrokinetic and electrohydrodynamic instabilities are still limited. The application of these instabilities to improve mixing between components should be explored. One example is through the use of multiphase systems where electrohydrodynamic instabilities are utilized to improve component partitioning for liquid extraction devices. 

Trebotich D, Chang W, Lippmarm D (2001) Modelling of blood flow in simple Microsystems, hr Modeling and simulation of rrricrosystems 2001, ISBN 0-9708275-0 ... 

To this end multiphysics simulations have been successfully employed to model and calculate hydrodynamic flow and the associated shear forces, transport phenomena due to diffusion and convection, the effects of Joule heating, as well as electrically induced forces acting on cells for the purpose of organ assembly and the resulting cell trajectories. Using this approach, microsystems may be evaluated with respect to the desired function even before building devices, enabling efficient optimization and acceleration of development [5]. 

It is dear from the examples presented above that there is now an enormous amount of work being performed on simulations of flows of relevance to microsystems. This is a very new field, as evidenced by the fact that most of the references dted have been pubhshed within the last 3 years. There are some common conclusions that can be drawn from the above work that are summarized below ... 

International Conference on Modeling and Simulations of Microsystems, 19-21 March 2001, Hilton Head Island, SC, 2001, pp. 223-226. 

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