chapter  4
26 Pages

Material modelling, numerical methods, numerical formulations, FEM modelling

In this paper we present an overview of our work on particle method based simulations of dynamics in MEMS (micro-electromechanical systems).

We consider both, process simulation and device simulation. The first example is the micro powder injection moulding (PIM) of powder filled polymers, where simulation is confronted by the complex rheology of a largely deforming feedstock with free surfaces. In the second example, the micro casting of metal alloys, large differences in length scales occur. Here we show that it is useful to couple the particle method to a grid-based approach. This technique is used to simulate thermal conduction between the alloy and the mould efficiently. The hybrid approach is also useful when we require coupling to electrostatic fields, which is illustrated in the third example where we show how the simulation of conveying a micropart (see Fig. 1) by means of electrowetting can benefit from particle methods. Eventually we give an example from device simulation with particle methods where we consider carbon nantotube resonators (CNT). We perform a molecular coarse-graining that results in a dissipative particle dynamics model. Without considering all the molecular details, this method naturally includes thermal fluctuations, which cannot be ignored on this length scale.