Novel Approach for Physical Modeling of Microfluidic Systems

The study of fluid flow in micro systems is still an open issue. Finite element models are generally used during prototyping. Such models are useful when the geometry has a large impact on device performance. Unfortunately, the nature of such methods and especially the mesh complexity limits simulation studies to non-transient or limited transient behavior. We present a different approach of microfluidic modeling, which is based on bond graph theory. Lumped component physics and power relations between the elements determine the dynamic behavior. In this way, dynamic simulations are ubiquitous and pave a way for control design. After introducing a number of basic microfluidic components, we concentrate on a case consisting of a three-valve micropump actuated peristaltically and connected to a thin, long tube. Input signals, device dimensions, electrical and mechanical material properties and fluid viscosity are explicitly present in the model and can be fitted for increased performance. Amongst others, simulations reveal the volume flow, pressure generation, and average fluid velocity throughout the model.