Simulation-based design of a micro fluidic transportation system for mobile applications based on ultrasonic actuation

Enabling efficient gas transport by small and integrated microsystems became of major interest and gained momentum since much more attention is paid to controlling the air quality in urban areas by the general public. In order to be able to locally detect low concentrations of gases or particulate matter (PM) being potentially harmful to health, e.g. by sensors incorporated in mobile devices, small and energy efficient micropumps are needed to increase the throughput of ambient air and in that way the measurement frequency. In this work, we propose the concept of an ultrasound-based microfluidic pump. In a first step, we evaluate actuation patterns in simple analytic pressure field simulations in order to investigate and design a phased array with tunable radiation angle. Then, the simulation models are extended to fully coupled finite element models (FEM) by taking into account fluid-solid interaction as well. However, upscaled prototypes showed no measurable gas transport. Taking into account our findings, subsequent FEM simulations with rectifying elements in the fluidic channel are conducted. In the end, we compare the efficiency of single-membrane actuators with multi-membrane actuators running in phase as well as out of phase.