| Temperature is an important control parameter during chemical reaction process. Micro reactors have attracted much attention due to its capability of excellent heat and mass transfer, fast reaction, and inherent safety of small scale. Among various types of micro reactors, micro droplet as a batch reactor has its own advantages such as high multiplexing capability. However, strong heat dissipation characteristics of microscale systems (due to large surface to volume ratio) hampers the measurement and monitor of enthalpy changes during the reaction.;This study mainly focuses on temperature monitoring at micro droplet reactor by using thin film resistance temperature detector (RTD). Indium tin oxide (ITO), optically transparent and electrically conductive material was used to fabricate a RTD. A simple reaction was carried out on (EWOD) digital microfluidic device. Droplets of strong base and strong acid were dispensed on an electrode with embedded ITO RTD, and they were allowed to react. This exothermic reaction released considerable amount of heat during reaction which was monitored by RTD temperature measurement. Due to high heat dissipation, very small temperature rise was observed because experiment was not carried out in a control environment. Multi-physics numerical modeling was carried out to determine the amount of overall heat loss through conduction, convection and evaporation. The numerical results were compared with the experimental data to examine the difference in heat transfer and evaporation rate. |
