A new microsystem designed to detect and measure in real time the enthalpy of mixingof two fluid constituents is presented. A preliminary approach to quantify the enthalpy of dilutionvalues or mixing is first discussed. Then, a coherent rationale leading to structure devicesoperating in real time is formulated, considering the straightforward assessment of heat-fluxtransducers (HFTs) capability. Basic thermodynamic observations regarding the analogy betweenthermal and electrical systems are highlighted prior consideration of practical examples involvingmixing water and alcohols. Fundamentals about HFT design are highlighted before presenting anadequate way to integrate both functions of mixing and measuring the entailed heat exchange astwo continuously flowing fluids interact with one another. Thereby, the development of a relevantprototype of such a dedicated microsystem is discussed. Its design, fabrication andimplementation under real operating conditions are presented together with its assessedperformance and limits so as to highlight the advantages and shortcomings of the concept.