Pool Boiling Experiments Using Surface Micromachined Thermocouples

A Thin Film Thermocouple (TFT) surface micro-machined on a Pyrex wafer was used to study micro-scale features in nucleate boiling. This study is relevant for various aerospace applications such as spray cooling, energy conversion devices and materials processing. The K-Type TFT was ~50 microns wide and ~250nm thick. A high speed digital data acquisition system was used to record the surface temperature fluctuations during pool boiling of PF-5060. The surface temperature transients were obtained at different superheats and data acquisition sampling rates up to 1 kHz. The spectra of surface temperature transients were analyzed using Fast Fourier Transform (FFT).