Implementation of a high-sensitivity thermoresistive microcalorimetric flow sensor: Comparison with a proposed 1D mathematical model and simulations

This study focuses on a Thermoresistive Microcalorimetric Flow (TMCF) sensor for measuring volumetric flow rates of deionized water. A one-dimensional model is proposed to analyze the thermal behavior of channel-type flow sensors, aiming to assess their sensitivity and operational performance. Simulations in COMSOL Multiphysics confirm that the model accurately predicts the sensor's behavior, validating its effectiveness. Experimental results further validate the mathematical model, confirming its accuracy. Additionally, the sensitivities, hysteresis, and response times of the TMCF sensor's temperature sensors were evaluated while operating in Constant Temperature Difference (CTD) mode. Experimental measurements of the sensor were performed on a voltage regulation circuit operating in Constant Temperature (CT) mode to obtain an anemometric response. These experimental results showed good agreement with simulations in COMSOL Multiphysics and later in LTSpice. It was found that these responses were three orders of magnitude smaller than those obtained in CTD mode. The fabrication methodology of the TMCF sensor was successfully implemented using glass substrates, as proposed in the mathematical model, and with the geometry defined in the simulations to enhance the sensor's response. • Proposal of an innovative flow rate sensor to measure water flow velocity in a range of 0 to 2.5 mm/s. • Development of the sensor using an amorphous semiconductor material, experimentally characterized to optimize sensitivity and performance. • Formulation of a mathematical model to predict the thermal behavior of a microcalorimetric flow rate sensor. • Validation of the model's reliability and accuracy through comparisons with simulations in the specialized software COMSOL Multiphysics®.