MICRO FLOW CALORIMETER FOR THERMOELECTRICAL DETECTION OF HEAT OF REACTION IN SMALL VOLUMES

A micro chip element with an integrated flow channel and thin film the rmopiles was developed in order to realize a micro calorimeter for sma ll volumes in a flow arrangement. The flow channel consists of two inl ets, a mixing region, a measurement region, and one outlet. Thermopile s of BiSb/Sb thermocouples were used as thermal transducers because of their extraordinary high thermopower. A thin film heater of a NiCr al loy was integrated in order to yield the possibility of internal elect rical calibration. In addition, this heater can be used for thermal mo dulation of the whole measurement system. The calorimeter was prepared using vacuum evaporation, PECVD and magnetron sputtering for thin fil m deposition and photolithography as well as chemical wet etching for microstructuring. The function of the device was tested to neutralize 400 nmole, 100 nmole and 10 nmole NaOH by H2SO4.