Abstract
In this study, micro square heaters having dimensions of $65{\times}65{\mu}m^2$and $100{\times}100{\mu}m^2$ were fabricated and bubble nucleation experiments on the heaters were performed. Bubble nucleation temperature was also measured using a bridge circuit and the photographs of bubble nucleation and subsequent growth were taken by a camera with a flash unit. Measured bubble nucleation temperatures were found to be closer to the superheat limit of working fluid (FC-72). Also quasi-1D analyses for the square heaters were performed. The quasi-1D analysis yielded proper temperature distribution of the square heater at steady state, however failed to predict the temperature rise up to the steady state. Similar time dependent temperature can be obtained with proper value of thermal diffusivity. For the $100{\times}100{\mu}m^2$ square heater, nucleation of several bubbles was observed while only one bubble was observed to be nucleated on $65{\times}65{\mu}m^2$ heater.