OpenFOAM Simulation of Microfluidic Molecular Communications: Method and Experimental Validation

The convergence of microfluidics and Molecular Communication (MC) has garnered significant attention in the context of the emerging Internet of Bio-Nano Things (IoBNT) paradigm. Microfluidic systems offer unique capabilities for manipulating fluids at the nanoscale, enabling precise control over molecular interactions. Potential IoBNT applications of microfluidic MC lie in healthcare, environmental monitoring, and biotechnology. The MultiPhase Particle-In-Cell (MPPIC) solver in OpenFOAM was originally intended for applications in sedimentation, separation, and granular flows. In contrast, in this methods article, we investigate the feasibility of utilizing the MPPIC solver in OpenFOAM for the simulation of microfluidic MC in the context of the IoBNT. This methods article thus provides a simulation framework for studying the intricate interplay between microfluidics and MC; the examined OpenFOAM simulation methodology can serve as a foundation for further research in the field of microfluidic MC simulation. Specifically, we compare our OpenFOAM simulations to an analytical model as well as to a particle-based simulation approach. For a uniform release of particles on the transmitter side and a flow-dominated regime, our simulation results demonstrate that the Channel Impulse Response (CIR) in the analytical approach and in the particle-based approach are similar to the OpenFOAM simulation results. As the geometry expands in the direction of fluid flow, the OpenFOAM simulations converge to the analytical model, especially for the tail of the CIR. In addition, we compare the OpenFOAM simulation results with measurements on a fluidic MC testbed in the millimeter scale. We find that the OpenFOAM simulation results closely approximate the experimental measurements for the flow-dominated regime with a Root-Mean-Square Error (RMSE) below 10 %.