Application of stereomicroscope in volumetric micro-PIV

Flow visualization offers valuable and accurate insights into flow characteristics. Doing tomographic volumetric measurements in micro-scale flows is challenging due to physical constraints to fit multiple cameras in a small field of view and ensuring that the entire depth of the measurement volume remains in focus. In this study, a novel stereo-microscope system with a high degree of overlap at high magnification between the two cameras is introduced, and its practical application for internal flow measurement within a microchannel is demonstrated. Therefore, the challenge of using two cameras which reduces volumetric reconstruction accuracy due to the underdetermination of the inverse problem of 3D reconstruction from fewer camera projections, is mitigated. We performed physical experiments to measure volumetric velocity within a phantom with an inner diameter of 3 mm. A validation step is performed by comparing experimental and theoretical velocity profiles. By validating the measured velocity profiles against established theoretical models, the reliability of the results and performance of the system is ensured. Any discrepancies between the measured and theoretical profiles are carefully analyzed and addressed to further refine and improve the measurement process.