Distributed colorimetric interferometer for mapping the pressure distribution in a complex microfluidics network

Abstract

We demonstrate a novel platform for mapping the pressure distribution of complex microfluidics networks with high spatial resolution. Our approach utilizes colorimetric interferometers enabled by lossy optical resonant cavities embedded in a silicon substrate. Detection of local pressures in real-time within a fluid network occurs by monitoring a reflected color emanating from each optical cavity. Pressure distribution measurements spanning a 1 cm² area with a spatial resolution of 50 μm have been achieved. We applied a machine-learning-assisted sensor calibration method to generate a dynamic measurement range from 0 to 5.0 psi, with 0.2 psi accuracy. Adjustments to this dynamic measurement range are possible to meet different application needs for monitoring flow conditions in complex microfluidics networks, for the timely detection of anomalies such as clogging or leakage at their occurring locations.