Optimization of microfluidic flow sensors for different flow ranges by FEM simulation

Finite element simulation and post-processing results of calorimetric type microfluidic mass flow sensors are presented. The output characteristics of a calorimetric flow sensor are functions of the geometrical position of the temperature sensor elements. A given flow sensor (with a given technology on a given substrate) can be optimized for different flow ranges by determining the position of the temperature sensor elements. The simplified mathematical model of the steady-state thermal profile along the microfluidic channel is presented. It is also shown how the output characteristics depend on the position of the temperature sensors and the ratio of the convective and conductive heat transfer. The optimal parameters of a silicon substrate based microfluidic flow sensor for low and for high flow ranges were calculated by FEM simulation. Based on the simulation results the silicon substrate based microfluidic flow sensor could be optimized for different flow ranges.